A MONOGRAPH ON THE POLYCHAETA OF SOUTHERN AFRICA PART I. ERRANTIA Publication 656 No. A MONOGRAPH ON THE POLYCHAETA OF SOUTHERN AFRICA PART I. ERRANTIA BY J. H. DAY, Professor of Zoology, University of Cape Town TRUSTEES OF THE BRITISH MUSEUM (NATURAL HISTORY) LONDON: 1967 Issued October, 1967 © Trustees of the Brilish Museum (Natural History) 1967 Polychaeta of Southern Africa. Pt. i Corrigenda p. 332. Corrigendum, legend to Fig. 14.12, substitute: Fig. 14. 12. Pseudonereis variegata. (a) Head, (b, c) Dorsal and ventral views of proboscis, (d) Anterior foot, (e) Falciger. (f) Posterior foot. Pjcwrfmifrra anoma/a (after Gravier, 1901). (g) Head and proboscis, (h) .\nterior foot, (i) Posterior foot, (j) Falciger. Perinsreis vancaunca. (k, l) Dorsal and ventral views of proboscis, (m) Anterior foot, (n) Posterior foot, (o) Falciger. Perinereis nuntia vallata. (p, q) Dorsal and ventral views of proboscis, (r) Posterior foot, (s) Falciger. p. 336. Corrigendum, legend to Fig. 14.13, substitute: Fig. 14. i^. Perimreii falsoiariegala. (a) Head, (b, c) Dorsal and ventral views of proboscis, (d) Falciger. (e) Anterior foot, (f) Posterior foot. Perinereis capemis. (o) Anterior foot, (h) Posterior foot, (i) Head, (j, k) Dorsal and ventral views of proboscis, (l) Foot of heteronereid form. (m) Falciger. Perinereis cultrifera. (o, p) Dorsal and ventral views of proboscis, (q) Posterior foot. Perinereis mgropunclata. (r) Head, (s) .Anterior foot, (t) Posterior foot, (u, v) Dorsal and ventral views of proboscis. Printed by Eyre and Spottiswoode Limited at Grosvcnor Press Portsmouth CONTENTS PART I Preface ....... Introduction A brief survey of polychaete literature Notes on using the monograph The distribution of polychaetes with particular reference to southern Africa. Planktonic polychaetes The main diagnostic characters of the Class Polychaeta Methods .... System.\tic Accoltnt Classification Key to the families. .Aphroditidae. PalmyTidae and Spintheridae . -Amphinomidae Pisionidae .... Phyllodocidae Pontodoridae and lospilidae Alciopidae .... Tomopteridae Typhloscolec i dae Pilargidae .... Hesionidae .... Syllidae .... Sphaerodoridae Nereidae .... Nephtyidae and Lacydoniidae . Glyceridae .... Eunicidae .... Index of Scientific Names in Part i Page Figures Map 12 13 16 19 ■20 0. - 0.6 30 I.I - 1. 21 115 2. 120 3- - 3-2 132 4- 136 5- - 5-7 167 6. 172 7- - 7-5 196 8. - 8.2 207 9- 214 10. -10.2 221 1 1. -II-3 233 12. -12.13 288 13- 291 14. -I4'3 33B i.^i- ->5-3 352 16. -16.6 374 '7- -17.10 PART 2 Introductio.n Notes on using the monograph Systematic .Accoitnt Classification Key to the families Spionidae .... Magelonidae .... Cirratulidae and Heterospionidae vii (2) Map (2) (2) 0.4- 0.6 459 18.1-18.9 494 IQ.I 49B 20.1-20.4 CONTENTS Systkmatic Accot'NT (cnnlil.) 'rroihocliartidac and Apistobiant iiid Clhactoplcridac Orbiniitlac I'araoiiidac Opiicliidac Cossuridae Scalibrrgmidae Capiicllidae . Arenicolidac . Maldanidae . Owcniidac and Steriiaspidae Flabclligcridae Sabellariidae . Peclinariidac. Anipliaretidae TercbcUidae . Sabcllidac . Serpulidae Glossary of Technic:al Tkrms References Index of Scientific Names in Parts i -,'9 5'- 533 555 570 581 5«3 59' 606 613 64H 652 667 678 686 706 7:." 79' 821 827 842 23- 24. 25- 26. 29- 30- 3'- 32- 33- 34- 35- 36. 37- 38. -22.2 -23.6 -24.4 -25.2 -27.2 -28.3 -29.2 -30.8 -324 -33-3 -34-2 -35-5 -36.10 -37-'o -38.7 PREFACE The polychaete fauna of southern Africa is very rich and varied. Over 800 species have already been recorded and there is no doubt that many more await discovery. Unfortunately the records and descriptions of the known species are scattered through more than 50 papers. There is thus an urgent need for a monograph not only as an aid for further taxonomic work but also for the rapid identification of common species for ecological and physiological studies. This monograph covers "southern Africa", here defined as the subcontinent south of the twentieth parallel and extending from the northern parts of South West Africa around the Cape of Good Hope to the port of Beira in Mocambique. For good measure the faunae of .Angola and Madagascar are included too but as these regions are poorly explored it is unlikely that the treatment given here is adequate. The coverage of planktonic species is good for most of the species known from the world oceans have been found in samples as widely distributed as Angola, the southern tip of the Agulhas Bank and Nosy Be in northern Madagascar. The depth range of benthonic species includes shore forms from coasts and estuaries to dredged forms from the edge of the continental shelf In general this is about 200 metres but there are also a few scattered records from greater depths, some exceeding 3000 metres. Undoubtedly many more species remain to be described from these deeper levels of the continental slope. The main purpose of this monograph is to provide an adequate description of all the species of polychaetes known from this area with keys for rapid identification. Since the fauna is incompletely known the keys cover many other genera and species, marked with an asterisk, which may later be found in the area. By the same token it is hoped that they will be useful to workers beyond the limits of southern Africa. Another purpose is to provide a check-list of the whole fauna with a summarised distribution of each species and references to the works in which the records will be found. The method of presenting this is novel and will be described on p. 2. The collections on which this work is based were made mainly by the University of Cape Town, and I have to thank my colleagues and many past students for assistance in the field. I also vvdsh to thank many other institutions for sending me material. Among these are the several South African universities and museums, the Division of Sea Fisheries, the National Institute of Oceanography in the United Kingdom, the British Museum (Natural History), the .\merican Museum of Natural History, the Berlin Museum, the Danish Museum in Copenhagen and the State Museum in Stockholm. Not only was I able to examine much South African material in this way, but I was also able in many cases to compare this material viii POI.VCIIAETA OF SOUTIIKRX AFRICA witli the types. The types (if my own new species have been deposited in two nuiseunis. Those of species described in "The polychaete fauna of South Africa: Part ■,"" I Day, i960), have been placed in the South African Museum, Cape Town; while tlie types of all of the other new species described by me from southern Africa ha\c been deposited in the British Museum (Natural History), London. This study has been carried on at intervals for more than 30 years and it would ha\e been impossible without generous financial aid from several sources. I would like to acknowledge my gratitude to the University of Cape Town, the South African Council for Scientific and Industrial Research, the CUunegie Corporation of New York, the Nuffield Foundation and the Oppenheimer Memorial Trust. Finally I would like to thank my many friends who have helped in the preparation of the monograph. First Miss Margaret Dcnholm for the laborious work of typing (and often retyping) the text. Next Miss V. J. Vanderplank, Miss Jenny Jarvis, Mr. George Branch and Miss Elizabeth Miinchmeyer who helped with the illu- strations and finally Mr. Reginald Sims and my many friends at the British Museum (Natural History) who ha\e advised and assisted in the actual publication. INTRODUCTION A BRIEF SURVEY OF POLYCHAETE LITER.\TURE The early classical accounts of what is now known as the Class Polychaeta of the Phylum Annelida dealt largely with the taxonomy of European species. General accounts such as those of Cuvier (1817), Savigny (1820), Audouin and Milne- Edwards (1832-33), Grube (1851), Qiiatrefages (1865), Malmgren (1867) and Ehlers (1864-68) brought order out of the chaotic group "Vermes". These are only a few of the more important works and many more will be found in the list of refer- ences at the end of this monograph, while detailed accounts of particular groups will be referred to under the introductions of the various families. The first com- prehensive account of the European fauna with clear descriptions, good figures and useful keys to the various families, genera and species was provided by Fauvel (1923 and 1927) in the Faune de France series of monographs. Fauvel's mono- graphs are invaluable to systematists everywhere. It is now known that polychaetes are the dominant organisms living in soft bottoms at all depths of the sea. While many hundreds of species await description, attention is now turning to ecological and physiological studies. For references to all branches of polychaeta research up to 1950 the reader is referred to Dr. Olga Hartman's "Literature of the polychaetous Annelids" published in 1951. Her "Catalogue of the polychaetous Annelids of the world" published in 1959 widi a supplement and index in 1965 is also a useful tool in systematic work. For details of anatomy and physiology the most recent general works are those of Dales (1963) on the Annehda and Fauvel (1959) in Grasse's "Traite de Zoologie" vol. V (i). Bullock and Hor- ridge (1965) give a detailed account of the structure and funcdon of the nervous system. Fauvel (1923 and 1927) covers most of the cosmopolitan and European species in southern Africa but does not deal with the tropical species which dominate the fauna of Madagascar, Mocambique and Natal. For these Indo-west-Pacific species the most useful works are Gravier's beautiful monographs on the Red Sea fauna (Gravier 1899- 1908), Fauvel (191 9) on the fauna of Madagascar and Fauvel (1930, 1932 and 1953) on Indian species. There are, of course, many other papers dealing with the Indo-west-Pacific fauna but there is no space to mention them all. The few subantarctic species which reach the colder waters of the Cape are covered by the works of Ehlers (1901), Monro (1930 and 1936) and the keys given by Hartman (1964). This leaves the endemic species which comprise about 36 per cent of the fauna of a POLVCHAETA OF SOUTHERN AFRICA southern Africa. Unfortunately there is no comprehensive work which covers these and the descriptions are scattered through some 57 papers, which are listed chrono- logically on p. ■!,. A Ijrief historical survey is given below. The earliest records of polychactes from southern .\frica were made by individual explorers and collectors such as W. C. Peters (1854) who collected along the coast of Mocambique and .T. .\. Wahlberg who collected in Natal and the Cape of Good Hope. The latter collection was later described by Kinbcrg (1858-1910). The most important of these early collections, however, was that made by Ludwig Schmarda and published in 1861. From 1850 onwards many scientific research \esscls called in at Table Bay en route to .Vntarctica or the Indian Ocean. Stimpson (1856) described a small col- lection made at the Cape by the U.S. vessel "Blake", Mcintosh (1885) described a fe\v South African species as part of the "Challenger" collections and Ehlers (1908 and 1913) described the collections made by the "\'aldivia" and the Deutches Slidpolar Expedition. The more recent expeditions which collected around southern .Africa are the "William Scoresby" and "Discovery" reported Ijy Monro (1930 and 193G), the "Meteor" reported by .\ugcner (1931) and the "Galathea" reported by Kirkcgaard (1959). The first collections made by local scientists at the Cape were those of Dr. Percival of the South .African Museum and Professor Gilchrist of the Uni\crsity of Cape Town. Percival's collection was described by Willey {1904) and Gilchrist's by Mcintosh (1904 and 1925). Meanwhile collections were also made in South West Africa by Captain Hupfcr and Professor Michaelsen. These were sent to the Zoological Museum in Hamburg and described by Augener (1918) in an important monograph co\ering the whole west /\frican polychaete fauna. Another important collection was made about the same time in Madagascar and described by Fauvel (1919). Professor T. .V. Stephenson's classic survey of the intertidal fauna and flora of South Africa stcUted in 1932 and the early polychaete collections were described by Monro (1933 ''""i '037)- My own work also started at this time (Day 1934) and in 1938 I joined Professor Stej^henson and made intertidal collections all around the South African coast. ^VorId War II interrupted the work and the intertidal collections were described much later along with the estuarine species in 1951, 1953, 1955 and 1957. The ecological surveys were then extended below tide marks and the poKchaetes were reported in Day i()Go, 1961, 1963 and 1963a. The more recent collections still have to be sorted and work on the shelf fauna will continue. Little has been published on planktonic polychaetes from southern Africa. .A few scattered records from the area will be found in the works of Ehlers (1913 and 1917), Monro (1930 and 1936) and Tebble (i960). By and large, however, all these works deal with the South ,\tlantic and .Antarctic seas. My own work on planktonic polychaetes from southern .Africa is still unpublished though descrijitions and a summ.iry of the ri-cords have been included in this monograph. NOTES ON USING THE .MONOGRAPH \Vhen identilying material from a p.uticular area it is first necessary to know INTRODUCTION what papers contain original records or descriptions of the fauna. These are not easy to recognise in a long list of references such as that at the end of this mono- graph. For this reason a complete chronological list is given below. 1. Peters, W. C, 1854 2. Stimpson, W., 1856 3. Kinberg, J. G., 1858-1910 4. Schmarda, L. K., 1861 5. Baird, W., 1865b 6. Quatrefages, A. de, 1865 7. Kinberg, J. G., 1867 8. Grube, E., 1867 9. Grube, E., 1869 10. Mcintosh, W. C., 1885 11. Marenzeller, E. von, 1887 12. Willey, A., 1904 13. Mcintosh, W. C., 1904 14. Cravier, C., 1905c 15. Ehlers, E., 1908a 16. Ehlers, E., 1908 17. Gravier, C., igog 18. Ash worth, J., igio ig. AshworthjJ., 191 1 20. PLxell, H., igi3 21. Ehlers, E., 191 3 22. Ramsay, L., 1914 23. Horst, R., 1917 24. Ehlers, E., igi? 25. Horst, R., igi8 26. Augener, H., igi8 27. Fauvel, P., 1919 28. Fauvel, P., 1921 29. Treadwell, A. L., 1921 30. Seidler, H. J., 1923 31. Fauvel, P., 1923a 32. Mcintosh, W. C., 1925 33. Monro, C. C. A., 1930 34. Augener, H., 1931 35. Monro, C. C. A., ig33 36. Day, J. H., ig34 37. Monro, C. C. A., 1936 38. Monro, C. C. A., 1937 39. Treadwell, A. L., 1943 40. Day, J. H., 1951 41. Day, J. H., 1953 42. Tebble, N., 1953 43. Tebble, N., 1953a 44. Day, J. H., 1955 45- Day.J. H., 1957 46. Banse, K., 1957 47. Wilson, D. P., 1958 48. Kirkegaard,J. B., 1959 4g. Tebble, N., i960 50. Day, J. H., i960 51. Day, J. H., 1961 52. Uschakov, P. V., 1962 53. Day, J. H., 1962 54. Laubier, L., 1962 55. Day, J. H., 1963 56. Day, J. H., 1963a 57. BeUan, G. and Picard, J., 1965 — Day, J. H., unpublished records In biogeographical studies one must know what species are found in the area covered by the monograph, where and at what depth they occur and what synonyms have been used in earlier works. It is hoped that the species lists appended to each family will supply this information rapidly and that the "Records" and "Distri- bution" will supply the further details that may be required. All the published records of polychactes from southern Africa, Angola and Madagascar have been extracted from the list of papers given above and other, more recent unpublished records have been added. The complete list of valid species is given family by family. Each list is arranged alphabetically for ease of reference with synonyms and incorrect identifications preceded by the word "as". All species names are annotated by a code showing which workers used that name and the province and depth in which the records were made. The code is explained as follows : POLYCHAETA OF SOUTHERN AFRICA Authorily for the record Shown by a number which refers to the numbered list of references given above. Province where collected A — Angola G ~ Cape Province M~ Madagascar N = Natal P = Portuguese East Africa (Mocambifjue) W= South West Africa Depth range a = abyssal (over looo metres) d = deep (100-499 metres) e — esluarine i — intertidal p -; planktonic s — shallow (1-99 metres) vd= very deep (500-999 metres) The use of the code is best shown by an example. Lepidonotus scmitectus is listed among the Polynoinae on p. 37 as follows: Lepidonotus semitectus Stimpson 2C4 (and other code numbers) as Lepidonotus wahlhergi Kinberc; sCaNi (and other code numbers) as Polvnoe trochiseophora Schmarda 4(4 The first record shc)ws that the valid name is Lepidonotus semitectus first used by Stimpson 1856 (code number 2 in the literature list) and his ixcord was made in the Cape Province (code letter C) in the intertidal zone (code i). The same specific name has been used by several other workers as shown by the other code numbers against it. The first synonym is L^epidonotus wahlhergi Kinberg and the code 3CiNi gives the reference to Kinberg's publication in 1858-1910 and the information that these specimens were collected in the intertidal zone in the Cape Province and Natal. The second synonym is Polynoe trochiseophora Schmarda and the code letters 4Ci show that Schmarda's name was published in 1861 and the specimens came from the intertidal zone of the Cape Province. Other synonyms and records follow and all of them together show the full range of synonyms which appear in the polychaete literature of southern Africa and that Lepidonotus semitectus is a common intertidal and shallow water species which extends from South West Afiica around the Cape of Good Hope to Natal. More detailed information is appended to the description of each s]5ecics. If there are only three or four locality records, all of them are given, and if there are many, a summary shows the limits of the geographical and bathymetric range. After careful consideration, it was decided that place names would not be as helpful as latitude and longitude since the names of many collecting stations would not be found on ordinary maps and, in any case, dredged and plankton records would have to be given in degrees of latitude and longitude. Minutes of latitude and longitude have also been omitted for the sake of brevity and this means that unless the reader refers to the publication from ^vhich the record has been extracted, he will not be able to pinpoint the record more accurately than somewhere in the 60 mile square formed by a degree of latitude and longitude. For most purposes this is sufficient. Luckily the whole of southern Africa is covered by degrees of south latitude and east longitude so that the words "south" and "east" are omitted. Thus the locality can be expressed in four figures and the depth range by a letter. For example the records foi- Hcrmonia hrstri.\ described on p. 32 are shown as Cape (31/15/d) ; ? Natal (29/3 1, 's). This means that the species has been recorded in Cape wateis in the latitude/longitude square 3i'S/i5'E, in the depth range 100-499 metres ; there is INTRODUCTION 5 also a doubtful record from Natal in the latitude/longitude square 2g°S/3i°E in the depth range 1-99 metres. Reference to the map facing p. 9 will show that the Cape record is off Lamberts Bay and the doubtful Natal record is close to Durban. Distribution beyond the limits of southern Africa is given in the conventional form and a code letter signifying the depth range has been added when this information is available. It is urged that some indication of depth range should always be added to summaries of distribution since the fauna at different depths may differ markedly. For example tropical species are restricted to intertidal and shallow depths while the very deep and abyssal bottoms may be colonised by cold water species. It may also be noted that the summary of distribution given in this monograph has been deliberately selected from twentieth century reports of well known taxonomists since earlier works are not always reliable. THE DISTRIBUTION OF POLYCH.\ETES WITH P.VRTICULAR REFERENCE TO SOUTHERN .^RICA Polychaetes are an ancient group of worms. They are characteristically marine and the great majority are benthonic though some 50 planktonic species are dis- tributed throughout the oceans of the world. Benthonic polychaetes are probably the commonest type of macroscopic animal on sandy or muddy bottoms and they extend from the sea shore to the greatest depths of the hadal zone that have yet been sampled. They are also common in estuaries and a few species extend into fresh water although none of these have been recorded from southern Africa. In marine environments many species are very widely distributed. This is not surprising among planktonic forms for they are typically oceanic rather than neritic and the oceanic forms of all groups of animals are widespread. Among benthonic animals, however, a world-wide distribution is very unusual. None the less many benthonic polychaetes are known from all the oceans of the world and from the Arctic to the Antarctic. Species such as Chaetopterus varieopedatus, Owenia fusiformis and Hydroides norvegica seem to have been recorded from all seas that have been thoroughly investigated. Many other examples might be quoted and this has led some investigators to claim that the bulk of the Polychaeta are not restricted to the zoogeographical regions. This, however, is an overstatement. In the case of Dio- patra neapolitana which was reported to have a cosmopolitan distribution, it was found that several closely related species had been misidentified and when other "cosmo- politan" species are studied more carefully it will probably be found that many of them have been misidentified in the past. Current work on .Xephtrs hombergi suggests that this is another "cosmopolitan" species which has gained its reputation through misidentification. Another widely distributed group is the circumtropical group of species. Eurythoe complanata is a good example for it is found in the shallow waters of all tropical seas. Other tropical species are more limited. For example Iphione muricata is an Indo- west-Pacific species which extends from the Red Sea down the coast of .Africa to Natal and across the Indian Ocean to Indonesia and thence through the western Pacific to southern Japan and the Great Barrier Reef and New Caledonia. In 6 i'Oi,\'t:iiAi: TA (ir sonrmcRX africia liopiral America it is replaced b)- llie related Ibriii Ijiltwne ovata which occurs on both the Pacilic and Atlantic coasts. In the Atlantic ocean there is a large groiijj of species which appears to l)e restricted to temperate waters for many Atlantic species have been recorded from the coasts of Emope and \Vest Africa as far south as Cape Verde. They arc not known from tropical western Africa but reappear in the cool waters of South West Africa and extend dcnsn to C^ape Agulhas. Possibly they will later be discovered in deeper and thus cooler wati-rs in tropical latitudes. This at any rate is the general theory regarding bipolar distribution. The account given thus far has stressed the widesjsread distribution of four groups of species. Rut there are many other more restricted groups. The work of Dr. Olga Hartmaii .ind othtr ,\merican taxonomists has shown that the bulk of the new world fauna is distinct from that of the old world. Similarly Aimenkova and Uschakov have shown that there are characteristic species in the Arctic while Monro and others have described many species which are restricted to tlie Antarctic. As will be shown later, about 36 per cent of the South African fauna is endemic. Obviously a great deal more remains to be done in many parts of the world and many of the early records need revision but there is already sulTicient evidence that the distri- bution of polychaetes is essentially similar to that of other shallow water marine animals described by Ekman (1953). \\'ithin the limits of southern Africa (dehncd earlier as Africa south of tlie twentieth parallel of latitude) the ])atterns of distribution of the intertidal marine fauna and llora arc related to the ocean eiurents. This has been shown conclusively by Stephenson in a long scries of papirs summarised in Stephenson (1941, 1944 and 1947). Stephenson's intertidal survey is now being extended downwards to the edge of the continental shelf. In these deeper \\aters the currents change and sea tempera- tures are imiform o\'er much wider areas of sea bottom than they are in the intertidal zone. The work is incomplete for an adef[uate coverage of '-!,-,oo miles of coast and continental shelf takes a long time. In ])artieular, little is yet known of the shelf fauna of Natal and Mocambicjue. None the less a preliminary analysis of the poly- chaete fauna of southern Africa from the intertidal zf)ne to about 200 metres provides a useful introduction to further study and is given below. Earlier discussions of polychaete distribution in different parts of southern Africa will be found in Augener (1918), Fauvel (191 9), Day (1957) and Kirkegaard (1959). As mentioned earlier, about 750 species of polychaetes are known from this region and altogether there must be over 5000 records. A random sample of this fauna was obtained by extracting those benthonic species whose generic names started with the letters A to F. This ga\e 171 species. A preliminary inspection showed that 46 had been recorded from only one locality in southern Africa and a further 25 were known from only two. All of these were rejected as being too rare for dis- tribution analysis and the remaining too species which w'ere known from three or more localities were analysed further. An analysis of the recorded depths showed that there arc very few records of more than 200 mc'tres so that practicalK nutliing is known of the cU-chibenthal or abyssal fauna and all the notes on distributinn that follow a]3ply to the intertidal and shelf INTRODUCTION 1 < l/l d > g < < 5 I O c z a 1 U _) (- z c Q. UJ D- < < I < < z 1/1 >- z I H- UJ s 00 _l tu cr UJ hi I (/I < CD 2: < m n Q 8^ 31 UJ z a s < I z a: < o < < < Cosmopolitan 12 ?. 3 r~ fi ^z — 7 in 1? 11 10 q 7 7 fi fi 4 CIRCUN- Tropical 13 1 3 5 5 ■s fi 11 12 11 9 Tropical Indo-west Pacific 15 7 3 3 3 4 3 3 6 1? 14 13 1? Atlantic 13 2 3 6 ": — ~ ^- - 11 12 12 !0 9 6 3 Southern 1 1 ] 1 A A 3 3 other Foreign 7 0. _ 1 5 6 fi 5 fi U 4 4 2 1 Endemic 36 - n 1 z fi S — - ~ 17 ?3 ?a ?R 27 ?? Ifi 9 2 Total RFr.nRn<; 3 11 32 37 49 66 70 64 56 50 47 38 30 25 Fig. o.r. Distribution of faunistic components in a random sample of loo polychaetes from southern Africa. 8 POLVCHAETA OF SOUTHERN AFRICA fauna. Of the loo species, 63 liad been recorded from both the shore and the shallows while 37 had never been recorded from the intcrtidal zone. This suggests that there arc twice as many species whicli are intcrtidal in some part of their range than those that are confined to deeper levels of the shelf. In passing it may be noted that there are \'ery fi-w species that are confined to the intcrtidal zone and never extend below Inw tide marks. One characteristic intcrtidal species that springs to mind is the serpulid Poniatoleios kraussi. The geographical distribution of the too species sample from Angola around the Cape to Mocambique and Madagascar is shown graphically in fig. o.i. The main collecting stations are separated by intervals corresponding to the geographical distances between them and the range of each species is shown as a line joining the limits of the recorded distribution. This implies that the distribution is continuous between these points and for most species the locality records are scattered at fairly regular intervals throughout this range. Only in one case {Eurylhoe complanata) is the distribution believed to be discontinuous. This species is circum- tropical in distribution and in southern Africa it has been recorded from the tropical waters of Angola but is absent from the cold waters of South West Africa and the temperate waters of the southern Cape. It reappears again in the subtropical waters of Natal. It is significant that only one species out of the sample too has this type of discontinuous distribution. The sample 100 species has been divided into six faunistic components on the basis of their distribution beyond the limits of southern Africa and each component is described in turn. Table I Analysis of polychaete distribution around southern Africa 3 CT >^ x; rt >. .a pS ^ J3 J3 > S 4J 60 m 1 Z ■3 a. be < OJ c 3 Si £ bo < ^ :i <£ ^ ^ (2 Q C s Number of records 3 1 1 32 37 49 66 70 64 56 50 47 38 30 25 % Cosmopolitan 67 27 '9 '9 20 18 16 16 16 '4 15 16 20 16 % Circumtropical 33 5 7 8 9 16 23 32 37 3b °a Indio-Pacific 6 8 6 5 6 5 5 12 26 37 43 48 % .Atlantic 6 8 12 17 17 19 18 18 13 8 °a Southern 9 3 3 2 6 6 5 5 °o Other foreign 9 16 16 12 8 9 6 7 8 4 3 °o Endemic 55 50 47 47 42 40 42 49 32 ■9 5 ecorded oceans, e 12 are 1 Africa, ction of position lere the cosmo- •llccting t of the 1 in the itic and .s noted 1 absent ecorded las been .hich is |ue and ■re they Bashee ly). In juthern mbique ch are 3 warm limit is ;y form irds in ter two around ay that ds into e been ■.e tem- ranean iwever, of the s com- as the \r 13" M" 15° \6' 17" 18' 19^ 20 .-- ir- XT 23° 24= 25" 26° 27= 28° 29° 30° 31° 32° 33° 34° 35° 36° 3T 12° 13° I '" '^° 16^^ '7° ,8° ,9° 20° 21° 2r 23° 24 25° 26° 27° 28° 29° 30° 31° 32° 33° 34° 35° 36° 37° INTRODUCTION g 1. The Cosmopolitan Component includes those species which have been recorded from the tropics and the northern and southern cold temperate zones of all oceans. Some species are known from polar seas as well. In the lOO species sample 12 are cosmopolitan and it will be seen that they are distributed all around southern Africa. The actual number recorded at any one collecting station is mainly a reflection of the intensity of collecting in that area. For this reason the percentage composition of the total records from each locality is shown in Table i. From this it will be evident that apart from Angola and Walvis Bay where the total number of records is too small to provide reliable percentages, the cosmo- politan component forms a very constant proportion of the fauna at all collecting stations. In brief the cosmopolitan component comprises about 12 per cent of the total fauna of southern Africa and is uniformly distributed around its coasts. 2. The Circumtropical Component includes those species which are common in the tropics but may extend into warm temperate waters of the Indian, Atlantic and Pacific oceans. Thirteen such species occur in the 100 species sample. As noted earlier only one has a discontinuous distribution and occurs in Angola, is absent from the Cape and reappears in Natal. The other 12 species have been recorded from the tropical Atlantic but not from Angola possibly because little work has been done there. Neither have they been recorded from South West Africa which is bathed by cold water. They are, however, strongly represented in Mocambique and Madagascar where they form more than 30 per cent of the fauna. From here they extend southwards in decreasing numbers. There is a marked fall at the Bashee River in the Transkei but a few reach the east side of Cape Point (False Bay). In brief the circumtropical component forms 13 per cent of the total fauna of southern Africa ; it is largely restricted to the tropical and subtropical shores of Mocambique and Natal. 3. The Tropical Indo-west-Pacific Component includes those species which are common in the tropical Indian Ocean or western Pacific but may extend into warm temperate waters. The western limit is the Mediterranean and the eastern limit is Hawaii. Fifteen species belonging to this group occur in the sample 100. They form more than 40 per cent of the fauna of Madagascar and extend southwards in decreasing numbers. There is a marked fall at tlie Bashee River but thereafter two to three species which form about 6 per cent of the local fauna extend all around the southern tip of Africa to Luderitz in South West Africa. It is noteworthy that there is no reduction at Cape Point and that tliis tropical component extends into the cold Benguela Current. It is possible diat South Africa endemics have been derived from cold tolerant forms of this group of Indo-west-Pacific species. 4. The Atlantic Component includes those species which are common in the tem- perate waters of the North Atlantic. Some of them extend into the Mediterranean and a few extend along the coasts of tropical western Africa. Most of them, however, appear to be absent from the tropics and reappear in the temperate waters of the South Atlantic. They have not been recorded from other oceans. In the sample 100, there are 13 of these Atlantic species showing that this com- ponent forms as strong an element in the total fauna of southern .Africa as the lo l'OI.VC:IIAr.T.\ OF .SOUrilF.KN .\FRIt;A cosmopolitan, llic lircunilropical or tlii- liulo-wt-sl-Pacilir conipoiu-nt. Tlicir dis- tribution williiii this art-a is surprisinj;. It liad l)rcn (.'xprctcd tiiat they would have been restricted to the Athuuic coasts between Walvis Bay and Cape Point, but in fact they seem to be most common along tlie south coast between Cape Point .md the Bashce River and some even reach Loureneo Marques. The Atlantic component is common in dredgings and it is possible that the strength of this component along the south coast is a rellection of the large number of dredgings on this part of the coast. 5. The Sonl/iiin Comjwncnl includes those spceirs whidi are widely distributcil in temperate or euld waters of the sduthern hmiisplure but do not extend to tlie tropics. Their range includes such areas as the Straits of Magellan, the Falkland Islands, Tristan da Cunha, Kerguelen, southern Australia and New Zealand. They do not reach Antarctica and it may be noted in passing that no typicall)' antarctic species occur in southern Africa. The southern component is represented fiy foiu- species in the sample 100. It is thus a small but delinite element in the total fuma. Most of the records come from dredgings and they are fairly evenly spread between Walvis Bay and Port Elizabeth. Since the bottom temperature on the continental shelf within tiiesc limits is V2 to 14'C;. the distribution of the southern component is understandable. 6. ''OlIiciFonigir ipcciis. Under this heading are huiiped all those species whose distribution extends beyond the limits of southern Africa but which cannot be assigned to any of the components defined abo\e. It is probable that they really belong to one t>f the other components but their distribution is imperfectly known and some of the anomalous records may be due to misidentifieations. Records in southern Africa do not reveal any obvious pattern but the species tend to form a more important group on the Atlantic coast than elsewhere. 7. The Endemie Component includes those species which have not been recorded beyond the limits of southern Africa as defined earlier. There are 36 such species in the sample 100 showing that the endemic comjjoncnt is about 36 per cent of the total fauna. The percentage of endemics at the different stations along the coast is particularly interesting. Table i shows that the percentage remains practically constant along the whole coast from Luderilz to Port Elizabeth. At Walvis Bay there is a slight increase to 55 per cent but as this re]3rescnts 6 species out of 1 1 this change may not be significant in which case endemics would form about 43 per cent of the fauna at any jioint from South West Africa south and east to Port Elizabeth. Further along the coast llie iicrccntage of endemics drojis abruptly to 32 per cent at Bashee River, 19 per cent at Dinban and 5 per cent at Loureneo Marcpies. This sample shows no endemics further to the north biU more complete records indicate that 1-2 per cent reach Inhambane. It has often been implied that there are two grou]5s of endemics in sovuhern Africa or even tluci'. This has arisen frum tlie wurk ol' Stephenson on the imertifial biota who showed that there is a subtropical liicila in Natal, a waini temperate biota on the suulliirn coasts of the Clapc and a cold temperate biota f)n the west or Atlantic coast stretching as far north as C:a|ie Frio in South West Afiica. These INTRODUCTION i: three divisions of the total biota which includes of course not only the endemic component but all the other components as well, will be considered shortly but as far as the endemic polychaetes are concerned there is no evidence of two distinctive groups let alone three. Reference to fig. o.i shows that the range of individual endemic species is very variable. Some are restricted to the west coast, some extend from various points on the west coast to the south coast or Natal, some are restricted to the south coast and others extend from there onto the coast of Natal or even reach Lourenco Marques. None are restricted to the Natal coast. When all the endemic species are considered together they do not form two distinct groups, one centred on the west coast, and the other centred on the south coast, but rather a single group. It is concluded that there is one endemic polychaetc fauna in southern Africa. Faunistic Provinces in Southern Africa When the various components of the polychaete fauna are considered together certain conclusions may be drawn. It would appear that the fauna of Madagascar and Mocambique is very similar and is composed mainly of circumtropical and Indo-west-Pacific species along with a few ever-present cosmopolitan forms. The strength of the tropical components in this area is not surprising considering the sea temperature is usually above •25°C. South of Lourenco Marques which is incidentally the southern limit of coral reefs though not of individual coral growths, there is a weakening of the tropical components and an increase of endemics and other com- ponents. This change continues along the Natal coast and becomes very marked at Bashee River which seems to be a critical point in geographical distribution. It is at this point that the warm Agulhas Current swings away from the coast and a wedge of cooler water lies over the shelf and occasionally comes to the surface inshore when the Agulhas Current swings further out to sea. From Bashee River south and west to Cape Point the tropical components are weak and other components are more important. The endemic component in particular forms almost half the fauna at any point. From Cape Point northwards along the Atlantic coasts the fauna is very similar to the south coasts ; it is true that the remnants of the circum- tropical component do not pass Cape Point but the Indo-west-Pacific component does not decrease any further and the endemic component remains equally strong. In brief there certainly are changes in the polychaete fauna in the vicinity of Cape Point but they are not marked. Cape Point is not as marked a barrier as is Bashee River. This finding is very different from that of Stephenson but it should be remembered that he was working on the intertidal biota alone and here the poly- chaete fauna both of the intertidal zone and the whole continental shelf down to a depth of 200 metres is being considered. When hydrographic conditions are examined the significance of the wider depth range is apparent. The intertidal zone of the south coast from Bashee River to Cape Point is bathed by surface waters which have a temperature range of about 15° to 20°C. whereas from Cape Point north along the west coast to South West Africa the intertidal temperatures are about 12° to i5°C. As a result there are distinct intertidal biotas on the two coasts. 12 rOLVC:HAEl'.\ OF SOUIHERN AFRKiA At a depth of too metres the bottom temperature is surprisingly uniform at 12° to 14° C. from Port Elizabeth on around Cape Point and northwards along the west coast to Luderitz. In this case it is not surprising that there is one shelf fauna and that those species which can tolerate a bathymctric range of o-ioo metres can extend all around southern x\frica from the Bashce River to South West Africa. On the basis of the evidence presented above it is possible to summarise the faunistic provinces in southern Africa as follows : 1. The Mocambique-Madagascar pro\ince dominated by tropical species. This reaches Lourenco Marques. 2. The Natal province with many tropical species but also fair numbers of endenrics and Atlantic species. This reaches Bashee River. 3. The Cape and South West African province dominated by endemics but with a few tropical species and several other components. The intcrtidal fauna of this province diflTers on the Indian and Atlantic coasts. 4. Angola is dominated by tropical western African species and is quite distinct from South ^Vcst Africa. The faunistic boundary between the two is still unknown but probably lies to the north of Cape Frio. PLANKTOXIC POLYCHAETA Although the larvae of most polychactes are planktonic and the sexual stages of certain families such as the Syllidae and Nereidae are found at night in tow-ncttings over shallow water, the great majority of adult polychactes arc benthonic. Holo- planktonic species belong to six families namely the Phyllodocidae (subfamily Lopadorhynchinae), Pontodoridae, lospilidae, Alciopidae, Tomopteridae and Typhloscolecidac. Certain genera of the Polynoinae such as Dreischia and Nectochaeta have also been found in the plankton but these are almost certainly the late larval stages of the benthonic genus Lepidnsthenia. The planktonic families are all highly transparent and probably carnivorous though a careful search of the transparent gut has failed to reveal recognisable prey ; on the other hand there is no sign of phytoplankton either. Probably the most highly specialised for planktonic life arc the Tomoptftidae in which setae are replaced by membraneous pinnules and the Alciopidae which have enormous eyes as well as vesicula seminalcs and receptacula seminis for the direct transference of sperm. Useful references to planktonic forms will be found in Grceff (1885), Reibisch (1895), Apstcin (igoo), Rosa (1908), Southern (1909), Stop-Bowitz (1948), Dales (1957) and Tebble (1963). The earlier workers give descriptions and figures of the various species. Stop-Bowitz provides a useful review, Dales has drawn up a valuable key to most of the species and Tebble has discussed their distribution. Although they are never common in plankton samples, planktonic polychactes are very widely distributed and se\cral species occur at great depths. In all the oceans of tlie world there are probably less than 60 species of whicii 48 are now reported from the seas around southern Africa. They are typically oceanic and a neritic plankton sainple may be distinguished from an oceanic one by the fact that INTRODUCTION 13 it contains numerous benthonic larvae but few holoplanktonic forms. A few species may prove useful indicators of specific water masses. Thus Tomopteris carpenteri and Vanadis anlarctica are restricted to the southern oceans south of the subtropical convergence. Tomopteris dunckeri on the other hand appears to be restricted to the warm surface layers of the Indian Ocean. Tomopteris septentrionalis has been reported from most oceans but the early records were not made with closing nets and thus do not show at what depth the worm was living. In South African seas it is limited to cooler waters; it reaches the surface off die Cape Peninsula but is restricted to much deeper layers off Natal. This submergence under warm water masses may be the key to the wide distribution of many other species as well. THE MAIN DIAGNOSTIC CHARACTERS OF THE POLYCHAETA While no attempt will be made to describe the detailed morphology of the Polychaeta, a brief description of external structures is necessary here as an intro- duction to taxonomic studies. A glossary of technical terms is set out on p. 821. Basically the whole body of a polychaete worm consists of a cephalic lobe or pro- stornium, a segmented body or metastomium and a tail end or pygidium on which the anus opens. Each is formed from a different part of the trochophore larva. The pro- stomium is formed from the pretrochal region in front of the ciliated girdle or pro- totroch, the pygidium is formed from the posterior end which bears the telotroch while the metastomium is formed by segmental division of the part between the prototroch and the telotroch. The most anterior segments are formed first and while the worm grows new segments are continually being formed in front of the pygidium. In most polychaetes additional segments are added throughout life but in a few genera (e.g. Ophelia) the number of segments is fixed and is an important specific character. The Prostomium. This is a pre-oral lobe which contains the cerebral ganglia and bears the most important sense organs. In primitive forms there are two pairs of eyes, three antennae (a median and two laterals) , a pair of ventro-lateral palps and a pair of postero-lateral nuchal organs in the form of ciliated pits or grooves. In some families such as the Nereidae the distal part of the palp or palpostyle is separated from the proximal part or palpophore by a deep groove so that the whole palp is two- jointed. All the prostomial sense organs are best developed in the Polychaeta Errantia which are usually active carnivores. In the Polychaeta Sedentaria which are inactive microphagous feeders the antennae, prostomial palps and even the eyes may be lost and the whole prostomium may be fused too, and indistinguishable from the first metastomial segments or peristome which develops food-gathering organs. Even in errantiate forms which have adopted burrowing habits many of the prostomial sense organs are reduced or lost. The antennae may be reduced from three to two or even lost entirely, the palps and eyes may be lost and the prostomium is then reduced to a naked lobe above the mouth as is found in Lumbrineris. The Mouth. This is formed from a stomadeal invagination immediately behind the prototroch in what later becomes the buccal or peristomial segment. In the adult, the buccal cavity is eversible in errantiate families forming a proboscis which may be covered with papillae or provided with hard chitinous elements such as the 14 POLVCHAE'IA OF SOUTHERN AFRICA paragnaths and jaws of the Ncrcidac. These are of course used for feechnt; but in burrowing forms such as \ephlys, Ghcera and Arenicola the eversiblc proboscis is used for burrowing as well. In filter-feeding tubicolous forms such as Sabella and Serpula the buccal ca\ity is not eversiblc and there is no proboscis. The Parapodia. In most polychaetcs the first segment or the first few segments are modified and joined to the prostomium to form the head. This process of ccphalisa- tion will be described later but in the most primitive genera the whole Ijodv or metastomium consists of numerous similar segments each bearing a pair of lateral parapodia. These are typically biramous, with the parapodial trunk dividing to form a dorsal notopodium and a ventral neuropodium. The two rami are basically similar and each consists of a cirrus and a setigerous lobe bearing chitinous setae {olim chaetae) and supported by a stout internal chitinous rod or acicuhan. There are many modi- fications of this basic plan and any part of the parapodium may be suppressed cither along the w hole lengtli of the body or in some part of it. Thus all setae may be lacking so that the parapodium is achactous or the setigerous lobes may fail to develop leaving only the dorsal and ventral cirri and the segment becomes apodous. Finally the cirri may be lost or the setigerous lobes may develop without the cirii. Again the two rami of the parapodium may differ in structure. L'sually it is the notopodium which is reduced since it has less contact with the substratum. The dorsal cirrus often persists after the setigerous lobe of the notopodium has gone and the notopodial aciculum may remain embedded in the cirrophore or base of the dorsal cirrus. Such a parapodium is termed sub-biramous or sesquiramous. If however all notopodial setae and acicula are lost the parapodiuiu is truly uniramous. In a few cases the whole parapodial projection is lost so that the setae arise directly Irom the body wall as in the Oligochacta. The Setae. These chitinous structures show an infinite variety of form and do not change during preservation. They are thus of great importance in classification and many terms are used to describe them. The simplest forms arc slender hair-like structures appropriately called capillary setae or just capillaries. The distal end of the capillary seta may be flattened to form a blade [limbate capillary) or have a central axis with a blade on either side {winged capillary). They may be sculptured by the development of spinules, serrations, barbs or cusps. In the Errantia the neurosetae and e\cn the notosetae may be jointed so that the base or shaft articulates with a distal blade or apex. Such setae are termed compound in contrast to the normal unjointed or simple setae. If the shaft-head of a compound seta is symmetrical it is termed homogomph and if asymmetrical it is said to be heterogomph; similarly if the distal portion is a tapering blade it is termed spinigerous and if it is stout and blunt or hooked it is said to he falcigerous. Sometimes a simple seta becomes very stout like a projecting aciculum and is then termed an acicular seta. In the Sedentaria in particular, stout spines curved at the end commonly occur in the neuropodia. Earlier workers often referred to these as crotchets but they are no\v usually referred to as hooks even if they are only slightly curved. In some families these hooks have their ends protected by delicate bivalve hoods and are appropriately called hooded hooks. The most aberrant types of setae found in the Sedentaria are flattened plates provided with recurved teeth. They are termed uncini and may be rectangular with INTRODUCTION 15 numerous teeth or Z-shaped with a single main fang or rostrum surrounded by a crest of denticles. Further details arc described under the relevant families. Branchiae. Since the body wall is thin and the parapodia large, special respiratory organs are seldom developed by active forms but they commonly occur in tubicolous or sedentary forms. They may occur on any part of the body but are commonly dorsal in origin either on the dorsum itself or associated with the notopodium. Usually they are thin walled filaments richly supplied with blood but they may become complex branching organs. In filter-feeding fan worms the branchial crown on the head serves both as a respiratory organ and a food-gathering apparatus but in the deposit feeders the branchiae are separate from the buccal tentacles and occur on a few segments behind the head. Body Regions. As in other phyla of segmented animals there is a tendency for groups of segments to become specialised for different functions. The most obvious region is the AW formed of the prostomium and a few anterior segments which bear the feeding and sensory appendages. In tubicolous forms the head may be further specialised to form an operculum or plug when the worm retracts into its tube. Behind the head, tubicolous forms often develop a specialised anterior region or thorax often bearing the respiratory organs and behind this a posterior region or abdomen with poorly developed parapodia. When the end of the tube is open the last few segments may be specialised as a plug (e.g. the scaphe of Pectinaria) but usually the end of the tube is closed and the faecal pellets pass forward along a ventral groove or copragogue to be voided from the mouth of the tube. Cephnlisation. In its simplest form the head consists of the prostomium and the buccal segment or peristome. Apart from encircling the mouth, the peristome may be a normal segment with fully developed parapodia similar to those which follow. Such a peristome occurs in the family Amphinomidae. Usually however the peri- stome becomes specialised. In the Errantia the dorsal and ventral cirri often become elongated to act as tentacular cirri while the setigerous lobes and setae are reduced or disappear. Various degrees of this type of specialisation of the peristome occur in the Aphroditidae and in the genus Polynoe for example, only two or three setae remain at the bases of the tentacular cirri. The next segment however is normal apart from a slight elongation of the ventral cirri. Further cephalisation results in the fusion of additional segments to the peristome, the elongation of their cirri and the loss of their setigerous lobes. The Nereidae have four pairs of tentacular cirri derived from the fusion of two segments which have lost their setigerous lobes. The Phyllodocidae illustrate all stages of fusion of the first three segments and the loss of their setae while the Hesionidae have up to eight pairs of tentacular cirri derived from four segments. In burrouang forms which ingest organic particles buried in the mud the head is usually very simple and lacks appendages. In the Orbiniidae and Capitellidae for example the prostomium is a simple conical lobe without antennae or palps and the peristomial segment usually lacks both parapodia and setae. In deposit feeders the head may show many specialisations but usually the pro- stomium lacks appendages and the peristome or buccal segment develops a pair of i6 i>cilvc;h.\i:ta of southern Africa grooved food-gathering apjicudagcs called "paljDs" which pick up the focid particles from the surface and convey them to the mouth. These peristomial "palps" arise from the post-trochal region of the larva and thus differ not only in structure and function but also in origin from the sensory palps of the Errantiatc families which are pretrochal in origin. They should be given a separate name but it is difficult to conceive one which wDuId not cause confusion and the homologies of other food- gathering organs of the Sedentaria still have to be worked out. The peristomial palps of the Spionidae are certainly homologous with the peristomial palps of Dodecaccria and Tharxx among the C.irratuUdae. Further dissection has shown that the numerous grooxed tentacular filaments of Cirriformia are also peristomial in origin and thus homologous with the "palps"". In the Trochochactidae, grooved peristomial palps are again present but in addiuon there are diree dorsal digitiform appendages possibly derixed from the nuchal organs and the whole head is protected by a cephalic cage of lc)ng, forwardly directed setae originating from the second segment. A somewhat similar arrangement is foimd in the Flabelligeridae. The grooved palps are ob\iously homologous and the cephalic cage is now formed from setae of two, three or even four segments but the homologies of the "branchial filaments" are uncertain. The prostomium is reduced and fused to the peristomium and both are retractile into an introvert inside the cephalic cage. It is possible that the "branchial filaments" of the Flabelligeridae are homologous with the "nuchal organs of the Trochochactidae. The Pectinariidae, .'\mpharetidae and 'Fcrcbellidae are another group of deposit feeders which Hesslc (191 7) has shown to be fairly closely related. The Pectinariidae show the greatest degree of cephalisation for the prostomium is reduced to a cephalic veil protected by two fused segments which have grown forward over the dorsal surface to form an operculum. In the Ampharetidae the prostomium is not greatly modified but in the Terebellidac it is completely fused to the Ijuccal segment to form a tentacular lobe from which the food-gathering tentacles arise. According to Hessle (191 7) these tentacles arise from the prostomium but the \'iew adopted here is that they arise from the upper lip and arc stomadeal in origin. A. detailed discussion will be found in the Terebellidac. The Sabellidae and Serpulidae are suspension feeders which filter the plankton from the water by means of a branchial crown on the head. The prostomium is reduced and usually indistinguishable from the peristomium which bears a pair of branchial lobes each di\iiliil int" a semi-circle of bipinnate radioles. When the worm is feeding these radioles lurm a funnel of interlacing pinnules which trap the food particles in mucus and comey them along ciliated grooves to die palps and mnutli. In the .Serpulidae one ol the radioles is modified to f )rm an operculum t" plug the tube when die worm retracts. METHODS Collection. Polychaetes are one of the commonest groups of marine animals on the sea bottom and on soft substrata they usually form more than a third of all INTRODUCTION 17 the species collected. On the other hand most of them are small and seldom contri- bute greatly to the total biomass. They may be collected by all the methods com- monly used in marine biological work and for different purposes hand collecting, digging, dredging and grabbing are used. When sorting through the mud obtained by digging or grabbing it is important to remember than many species of polychaetes measure no more than a few millimetres in length and it is necessary to use a sieve of I mm. mesh if the majority of the species are required. A smaller mesh (e.g. 0-25 mm.) will naturally involve more labour and the additional specimens obtained are mainly post-larvae or small juveniles which are very difficult or impossible to identify. In many cases a good deal of sand will be retained by the i mm. mesh sieve along with the worms, small Crustacea and other animals. This should all be spread out in a shallow sorting tray with a little water. If the tray is tilted so as to expose the mixture of sand and animals for a few seconds and then straightened again so that the water flows back over the mixture, most of the small Crustacea which have a hydrophobic surface will be caught on the surface film and may be filtered off through a piece of plankton gauze. The small worms and sand grains which remain are then sorted by rough sedi- mentation. The whole mixture is washed into a large jar of 3 to 4 litres capacity and rapidly swirled around. Just sufficient time is allowed for the heavier sand grains to settle and the lighter animals are immediately poured off through a piece of plankton gauze. If this process is repeated five or six times very few worms are left mixed with the sand. Preservation. When engaged on routine dredging or grab-sampling at sea there is seldom time for elaborate and refined methods of preservation. After hand-sorting and sieving the whole catch is roughly sorted by size and the polychaetes and other small animals are washed into a cloth bag with a station label. The bag is simply placed into a large container, such as a five gallon milk churn, half-filled with 5 per cent formalin in sea water which has been neutralised with hexamine. In this way the polychaete catch may safely be stored for a few months before the formalin acidifies. The formalin/sea-water mixture must then be washed out with fresh- water, (the catch sorted to taxonomic groups) and the specimens preserved in 70 per cent alcohol. When using the rapid bulk methods described above many of the polychaetes will be twisted or broken and if time and facilities permit more refined methods should be used. While still alive the worms are washed in sea water and then relaxed. This may be done either by transferring them to a 7-5 per cent solution of MgCl2 or by adding alcohol drop by drop to the sea water over an hour. A piece of filter paper is then damped with sea water and placed on a slanting sheet of glass. The worms are then straightened out on the filter paper and 70 per cent alcohol pipetted over them until they are dead. With the sudden addition of the strong alcohol the probosces of Phyllodocids, Nereids and Glycerids are often everted and can be held in this position until the worm is fixed in a flat sorting tray of 70 per cent alcohol. None of the worms should be bottled until they are thoroughly hardened in the flat tray. i8 POLYCHAETA OF SOUTHERN AFRICA Disstxtion and the mounting of parajwdia. For taxonomic purposes it is often neces- sary to dissect out tlie proboscis to examine tiie jaws or other structures and it is always necessary to examine the parajiodia under a microscope. The proboscis of a hirge worm may be dissected with a pair of fine scissors but most worms are too small for this and the most useful instrument is a microscalpel shaped like a spear with a blade 2 to 3 millimetres long. If this is kept razor-sharp it is possible to dissect out the proboscis of a 5 nun. worm under a stereo dissecting microscope. For the removal of small parapodia the most useful instrument is a mounted needle which has been filed down to form an oblique cutting edge. It need not be particularly sharp for it is merely used to press down and sever the parapodium against the bottom of a glass dish. The parapodia are then transferred by means of a small pipette to a slide and mounted in a drop of glycero-formol. This is a half and half mixtmc of 5 per cent formalin and glycerine. The parapodium may be transferred directly to it from the 70 per cent alcohol and if a permanent slide is rec[uired the cover slip is later ringed with cement. THE SYSTEMATICS OF THE POLYCHAETA OF SOUTHERN AFRICA CLASSIFICATION The phylum Annelida to which the Polychaeta and several other groups of worms belong, is difiicult to classify into classes and orders. Earlier workers included the Archiannelida, Polychaeta, Myzostomida, Oligochaeta, Hirudinea, Echiura, Sipuncula and Priapulida. Recent workers, including Dales (1963), regard the last three groups as distinct and consider each of the other groups as a separate class of the phylum Annelida. The division of the class Polychaeta into orders has been attempted by Benham (1896) and Dales (1963). They have based their divisions on the structure of the head and the nature of the feeding organs, the regions of the body and the nature of the parapodia and setae. As shown earUer the method of feeding and the habitat whether it be planktonic, active crawling on the surface, burrowing in the mud or tubicolous does have an important effect on the structure of the head and body. However there are still many doubts regarding the homologies of the feeding organs and there is still no general agreement as to which families should be included in the various orders which have been erected. For this reason it is better to leave the matter open and agree with Fauvel (1923) and many earlier workers that for practical purposes the arbitrary grouping into Polychaeta Errantia and Polychaeta Sedentaria should be used. The Polychaeta Errantia includes active carnivores and a few others while the Polychaeta Sedentaria includes the remaining microphagous feeders. There are no mutually exclusive characters which define these two groups and a summation of characters is used in the following key. Key to the Families of Polychaet.\ Note Some families have such a wide range of characters that they appear twice in the key. In these cases a number in brackets refers to the other couplet in which the family appears. Most of the following characters; Prostomium with sensory appendages. Pharynx armed with jaws or teeth. Parapodia well developed and often bear compound setae . (Polych.\eta Err.\ntla) (p. 20) Most of the following characters: Prostomium seldom with sensor)' appendages and often fused to the peristome which may bear grooved palps, buccal cirri or a branchial crown. No jaws or teeth. Parapodia often reduced and compound setae very rare (Polychaeta Sedent.\ria) (p. 24 see also Part 2) 20 POLYCHAETA OF SOUTHERN AFRICA POLYCHAETA ErRANTIA (Part i) 1 Elytra {dorsal scales) present on many segments, at least in the anterior half of the body (fig. 0.2.1) .......... ,\PHR0DITII>.\F, (p. 30) - Elytra absent ............. 2 2 Notosetae in transverse rows across the dorsum. (Gills present or absent) ... 3 - Notosetae not in rows across the dorsum ........ 5 3 Neurosetac compound. Gills absent ......... 4 - Neurosetae simple. Rows of gills alternate with rows of notosetae AMPinNOMiDAE (6) (Euphrosine) (p. 120) 4 Notosetae are tlattened paleac not supported by membranes. Neurosetae not hooked (fig. 0.2.3) .......... Palmvridae (p. 115) - Notosetae slender and supported by membranes. Neurosetae are stout hooks (fig. 0.3.4) .Sphintiierid.\e (p. 119) 5 .\ sensor)' lobe (caruncle) behind the prostomium. Setae tubular, never compound (fig. 0.2.2) ......... Amphino.mid.'VE (4) (p. 120) - No caruncle behind the prostomium. Setae not tubular, often compound ... 6 6 Animal entirely planktonic with a clear translucent body ...... 7 - .Animal normally benthonic with an opaque body . . . . . . 12 7 Eyes enormous (fig. 0.3.7) ......■■ .-\lciopid.\e (p. 172) - Eyes normal, rudimentary, or absent ......... 8 8 Parapodia of body segments lack setae but have membraneous pinnules (fig, n.3.3) TOMOPTERIDAE (p. 1 96) — Parapodia of body segments have setae. Membranous pinnules absent ... 9 9 Setigerous lobe well developed and setae always compound . . . . 10 — Setigerous lobe small and setae always simple and acicular (fig. 0.3.6). (Large foliaceous dorsal and ventral cirri) ....... Typhloscolecidae (p. 207) 10 .Setigerous lobe produced as a slender thread among the setae (fig. 0.2.4) PONTODORIDAE (p. 167) — Setigerous lobe not so produced . . . . . . . . . 1 1 11 Antennae absent. Body cylindrical (fig. 0.2.3) .... Iospiud.\e (p. 168) — Four antennae. Body usually llattened . Phvllouocidae (22) (Lopadorhynchinae) (p. 156) 12 Prostomium with ventro-lateral palps ......... 13 — Prostomium without palps . . . . . . . . . . . 18 13 Palps bi-articulate with a stout basal joint and a small distal one . . . . 14 — Palps simple, sometimes cushion-shaped and partially fused to the prostomium . . 16 14 CompoLind setae absent. Never more than two pairs of tentacular cirri (fig. 0.2.9) Pilarcid.\e (p. 214) ■ — Compound setae present. Four or more pairs of tentacular cirri . . . . 15 KEY TO THE FAMILIES Fig. O.2. Illustrations of Family Characters, i, Aphroditidae. 2, Amphinomidae. 3, Palym- ridac. 4, Pontodoridae. 5, Syllidae. 6, lospUidae. 7, Pisionidae. 8, Eunicidae. 9, Pilargidae. (a) Eniire worm, (b) Head ; b*, b' maxillae and mandibles, (c) Foot. (d) Noloseta. (v) Neuroseta or seta of uniramous parapodium. POLYCIIAI-.TA OF SOUTHERN' AFRICA Jaws, if present, usually slyliform. Denticles absent. Tentacular cirri often jointed (tig. 0.3.1) .......... HllSIONID.'iE (p. denticles as well. Tentacular Nereidae (p. Syllidae (p. 8) PiSIONID.XE (p. . EUNICIDAE {22) (p. Sph.\erodoridae (p. — Two pairs of toothed jaws always present and often horn>' cirri smooth (fig. 0.3.2) ..... 16 A barrel-shaped gizzard follows the pharynx (fig. 0.2.5) — Gizzard absent ....... 17 Two pairs of jaws. Gills in\"ariably absent (fig. 0.2.7) — Four or more pairs of jaws. Gills may be present (fig. 0.2 18 Body papillose. Head indistinct (fig. 0.3.5) — Body smooth. Head distinct .... 19 Proboscis without jaws ..... — Proboscis with jaws ...... 20 Dorsal cirri lamellar, not annulated. (fig. 0.3.8). (No parapodial lamellae) Phyllodocid.ve (13) (p. — Dorsal cirri long and annulated (fig. 0.3.1). (Xo parapodial lamellae) Hesionid.ae ( 1 7) (p. — Dorsal cirri short and conical, not annulated (Parapodial lamellae present) Lacydoniid.\e (p. 21 One pair of jaws ..... Pil.m<.cid.\£ (16) (T.ahelesapia) (p. — Two or more pairs of jaws ........... 22 Peristome with parapodia and setae ......... — Peristome without parapodia or setae (fig. 0.2.81 .... F,unicid.\e (17) (p. 23 Prostomium a pointed cone. Body circular in .section. Parapodia without lamellae (fig. 0.3.10) .......... Glyceridae (p. — Prostomium pentagonal. Body square in section. Parapodia with lamellae (fig. 0.3.9) Nethtyidae (p. 221) 291) 233) 17 132) 374) 288) 19 20 21 136) 221) 350) 214) 22 23 374) 352) 338) KEY TO THE FAMILIES 23 Fig. 0.3. Illustrations of Family Characters. 1, Hesionidae. 2, Nereidae. 3, Tomopteridae. 4, Sphintheridae. 5, Sphacrodoridae. 6, Typhloscolecidae. 7, Alciopidae. 8, Phyllo- docidae. 9, Nephtyidae. 10, Glyceridae. (a) Entire worm, (b) Head, (c) Foot. (d) Notoseta. (v) Neuroseta or seta of uniramous parapodium. 24 POLVCniAETA OF SOUTin-:RN AKRKIA Polv{:haeta Sedentaria (Part 2) 1 Body short and stout with a tuft of filamentous anal gills (fig. 0.5.8) SiERNASPiixMi (p. 64H) — Body elongate. N'o anal gills .......... 2 2 Head modified by the development of frilly membranes (fig. 0.6.1b), buccal tentacles (tig. 0.6.6) or a branchial crown around the mouth (fig. 0.6.7). Prostoinium often reduced and indistinguishable from the buccal segment . . . . 17 — Head not greatly modified. Prostomium usually well developed and obvious. Buccal segment sometimes with parapodia and may bear a pair of adhesive palpj> (lig. 0.4. i h) or a few grooved tentacles (fig. 0.4.6b) . . . . . . . . 17 ■^ Buccal segment %vith tentacles retractile into the mouth (fig. 0.6.5) Ami'Hare'udae ('jj) (p. 6}J6) — Buccal segment with a pair of adliesive paljis (often broken ofT) or several grooved tentacles dorsally ............ 4 - — Buccal segment without food-gathering appendages of any sort . . . . lo 4 Hooded hooks (fig. 0.4. i.v) present in the posterior segments at least. Parapndia always well developed ............ 5 — Hooded hooks entirely absent. Parapodia sometimes reduced to mere ridges , . 6 5 Head fiattened and spade-shajjed. Gills absent. Paljis papillose (iig. 0.4.2) M.^oELONiD.\E (p. 494) ~ Head not flattened. Gills often present. Palps grooved (fig. 0.4.1) Spionidae (p. 459) 6 Long filamentous gills at least on anterior segments. Parapodia reduced to ridges . 7 — Gills not long and filamentous. Parapodia not in the form of ridges .... 8 7 Body divided into an anterior region of short segments and a posterior region of long segments (fig. 0.4.5) . ....... Heterospionidae (p. 518) — Body not divided into regions ; segments do not difier greatly in length (fig. 0.4.6) Girratulidae (p. 4(j8) 8 Both rami of anterior parapodia well develi>ped aiul ])rovidcd with long setae (fig. 0.4.4) TROC:UOCH.'\ETmAE (p. 5i()) — Either the nf>topodium or the ncurojxidium of anterior segments reduced or absent . 9 9 Anterior segments uniramous having no neuropodia. Posterior segments biramous with neurosetae in the form of minute uncini (fig. 0.4.3) • ■ Ghaetopteridae (p. 522) — Anterior segments with notopodia reduced to cirriform lobes with an internal aciculum but not setae (fig. 0.4.8) ....... Asimtobranchidae (p. 52 1) KEY TO THE FAMILIES 25 Fig. 0.4. lUuilrations of Family Characters, i, Spionidae. 2, Magelonidae. 3, Chaetopteridae. 4, Trorhochaetidae. 5, Heterospionidae. 6, Cirratulidae. 7, Orbiniidae. 8, Aspito- branchidae. (a) Entire worm, (b) Head, (ca) ■'\nterior foot, (cp) Posterior foot. (d) Notoseta. (v) Neuroseta. 26 l'OI.VCHAETA OF SOUTHERN AFRICA lo Dentate-crested hooks (fig. 0.5. 7\) present in posterior segments if not earlier . . 15 — No dentate-crested hooks ........... 1 1 It Capillary setae crcnulate (fig. 0.4. 7d) ...... Orbiniidae (p. 533) — Capillary setae not crenulate .......... 12 12 A single long filiform gill arising from the dorsum of sctiger 2 or 3 (fig. 0.5.3) CossrRiD.\E (p. 581) — Gills, if present, not single and median . . . . . . . . . 13 13 Capillary setae winged in anterior segments. ^\ median antenna may be present (fig. 0.5.1) PARj\oNinAE (p. 555) — Capillary setae not winged. A median antenna is never present .... 14 14 Prostominm a taj^crcd cone. Body fusifonn, often grooved ventrally (fig. 0-5.2) Opheliid.^e (p. 570) — Prostomiimi notched or lobed. Body swollen anteriorly but not grooved ventrally (fig. 0.5.4) ......... Sc.^LIBREGMIDAE (p. 583) 15 Dentate-crested hooks with hoods (fig. 0.5.5). Body resembling an oligochaete Capitellidae (p. 591) — Dentate-crested hooks without hoods. Body not resembling an oligochaete . , . 16 16 Middle segments greatly elongated but never anniilated (fig. 0.5.7). Gills rare Mai.danidae (p. 613) — Middle segments not greatly elongated but always annulated (fig. 0.5.6). Gills always present ........... Arenicolidae (p. G06) KEY TO THE FAMILIES 27 Fig. 0.5. Illustrations of Family Characters, i, Paraonidae. 2, Opheliidae. 3, Cossuridae. 4, Scalibregmidae. 5, Capitellidae. 6, Arenicolidae. 7, Maldanidae. 8, Stemaspidae. (a) Entire worm, (b) Head, (ca) Anterior foot, (cp) Posterior foot, (d) Notoseta. (v) Neuroseta. ■2 I Setae on liead usually in tlic form Flabelligeridae (p. (152) 28 POL veil AETA OF SOUTH KRN AFRICA 17 Head usually with a frilled food-gathering membrane. Never any tentacles, palps or bipinnate radioles (fig. 0.6. i) ....... Ovvf.niid.\e (p. I149) — Head without a frilled food-gathering membrane but lias either tentacles or palps or bipinnate radioles ............ 18 18 Head with stout setae ..... Head without setae ..... 19 Capillary setae annulated. No marked body regions of a cephalic cage (fig. 0.6.2) — Capillary setae not annulated. Body regions well marked. Setae on head are paleae which form part of an operculum ......... 20 20 Two to three rows of paleae. Caudal region long and cylindrical. Tube attached (fig. 0.6.3) .......... S.^BELL.\RnD.\E (p. 667J — One row of paleae. Claudal region short and llattcncd. T\ibe free (fig. 0.6.4) Pectinariidae (p. 678) 21 Head with soft tentacles for deposit feeding. Gills often present on the first few .segments. Setal types not inverted in the posterior region ....... 22 — Head with a crown of i^ipinnate radioles (fig. 0.6.7) ^^^ suspension feeding. Nc^ gills behind the head. Setal tyjDcs inverted in the posterior region .... 23 22 Tentacles retractile into the mouth. Tiiey are either grooved or papillose (fig. 0.6.5) AMPHARETin.\E (3) (p. (j86) — Tentacles n