40 



T.G. PILLAI AND HA. TEN HOVE 



of the worm when withdrawn into the tube, and thereby, 

 have an additional protective function. The form and 

 arrangement of the internal tube structures, in combination 

 with characters of the worms themselves, served to separate 

 the various species. They are absent in Serpula Linnaeus, 

 1758, and have not been described in any of the other known 

 genera of Serpulidae. They differ from the transverse tabulae 

 of certain serpulids, an account of which is given by Lom- 

 merzheim (1979). Another important character common to 

 the group is that, unlike in Serpula, the thoracic membranes 

 of the two sides are not united posterior to the thorax to form 

 a ventral flap or apron. 



In the search for a name for this group, the genera 

 Pseudoserpula Straughan, 1967 and Protoserpula Uchida, 

 1978, were considered, among others. The former was found 

 to be invalid, and an account of the study which led to this 

 conclusion is provided under Spiraserpula minuta, 

 (Straughan, 1967), in this paper. It was not possible to 

 examine the type specimen of Protoserpula to establish 

 whether it has ITS or not. It is not in the National Science 

 Museum, Tokyo, and other efforts to locate it were unsuc- 

 cessful. 



H. Zibrowius of Station Marine d'Endoume, Marseille, 

 who went through the manuscript of this paper, and the 

 second author discussed the group with M. Jager of Rohrbach 

 Zement, Dotternhausen, Germany, who re-examined the fos- 

 sil serpulids studied by him (Jager, 1983), and other material, 

 and found that some of them too possessed internal tube 

 structures, although they had not been reported earlier. The 

 collaboration which followed (pers. comm.) led to a study of 

 likely Cretaceous and Tertiary serpulid genera and species 

 (Pillai, 1993), which revealed that the group belongs to the 

 genus Spiraserpula Regenhardt, 1961, previously known only 

 from fossil species. Spiraserpula Regenhardt, 1961, has prior- 

 ity over Protoserpula Uchida, 1978, even if the latter were to 

 possess internal tube structures, henceforth referred to in the 

 text as ITS {vide Jager 1993)). Zibrowius (1972) described a 

 Recent spirorbid species belonging to the genus Neomicrorbis 

 Rovereto, 1904, which was previously known only from 

 Cretaceous and Tertiary fossils. 



In three of the Recent species of the genus Spiraserpula 

 definite proof of asexual reproduction was found, in the form 

 of branching tubes, corroborated by the presence of a parent 

 with a schizont in one tube of Spiraserpula snellii sp. nov. 

 Asexual reproduction had previously been reported for the 

 genera Filograna Berkeley, 1835, Filogranula Langerhans, 

 1884, Josephella Caullery & Mesnil, 1896, Salmacina Cla- 

 parede, 1870 and Rhodopsis Bush, 1905 (ten Hove, 1979; 

 Ben-Eliahu & ten Hove, 1989). Pillai (1993) reports the 

 occurrence of tube branching in the fossil species Spiraserpula 

 versipellis Regenhardt, 1961. It would not be surprising if it 

 turns out that scissiparity takes place in most, if not all, 

 species of the genus Spiraserpula, in view of their aggregated 

 occurrence. 



Nineteen species of Spiraserpula, including the three 

 known ones referred to above and an unnamed one, are 

 described. They come from the Mediterranean, Madeira, 

 Canary and Cape Verde Islands, Gulf of Mexico, the Carib- 

 bean and Panama, the northern Red Sea, Mozambique, the 

 eastern islands of Indonesia, Eastern Australia, Japan and 

 New Caledonia. 



METHODS AND MATERIALS 



The tubes and their internal structures, as well as whole 

 worms and parts were examined and drawn under a stereo 

 microscope fitted with a drawing attachment. Measurements 

 were taken with a pair of fine dividers against a scale having 

 an accuracy of 0.5 mm, of total length of the tube when 

 possible, external diameter of the tube, total length of the 

 worm, width of the thorax just posterior to the pair of collar 

 fascicles, length and diameter of operculum, length of the 

 opercular peduncle, and length of the longest radiole and its 

 pinnule-free tip when present. Radioles and thoracic seg- 

 ments were counted on both sides, while the abdominal 

 uncinal tori of one side were counted to determine the 

 number of abdominal segments. The chaetae were mounted 

 in polyvinyl lactophenol or aquamount and figured under the 

 oil immersion lens of a high power microscope fitted with a 

 drawing attachment. Measurements of chaetae were made 

 with an eyepiece micrometer standardised with a stage 

 micrometer. Scanning electron micrographs of chaetae of 

 some of the species are also provided (Plates 1-5). 



The sources of material have been detailed under the 

 respective descriptions as well as the acknowledgements. Full 

 details of E. Atlantic stations surveyed by the 'Tydeman' 

 Canary and Cape Verde Islands Expeditions of 1980, 1982 

 and 1986 (CANCAP-IV, VI and VII), (e.g. CANCAP 

 4.D14, 6.134) can be found in van der Land (1987); of E. 

 Indonesian stations sampled during the Indonesian-Dutch 

 Snellius II Expedition (e.g. Snellius II 4.051) in van der Land 

 & Sukarno (1986). The following abbreviations have been 

 used in the text: AM: Australian Museum, Sydney; AMNH: 

 American Museum of Natural History, New York; BM(NH): 

 British Museum (Natural History), London, presently. The 

 Natural History Museum, London; FSBC I: Florida Depart- 

 ment of Natural Resources, Invertebrate collection, St. 

 Petersburg, Florida; HUJ: The Hebrew University, Jerusa- 

 lem; MCZ: Museum of Comparative Zoology, Harvard; 

 NNM: Nationaal Natuurhistorisch Museum, Leiden (for- 

 merly Rijksmuseum van Natuurlijke Historie); NSMT: 

 National Science Museum, Tokyo; QM: Queensland 

 Museum, Brisbane; RMNH: Collection numbers of NNM; 

 SME: Station Marine d'Endoume, Marseille (most material 

 will be deposited later in the Musee Nationale d'Histoire 

 Naturelle, Paris); USNM: United States National Museum of 

 Natural History, Washington DC; V.Pol: Polychaete collec- 

 tion numbers of ZMA; ZLU: Zoological Laboratory, 

 Utrecht; ZMA: Zoologisch Museum, Instituut voor Taxo- 

 nomische Zoologie, Amsterdam; ZMH; Zoologisches Insti- 

 tut und Zoologisches Museum, Hamburg; ZMK: Zoologisk 

 Museum, Kobenhavn. 



TERMINOLOGY 



The terminology used in this paper is explained in Figs 1 and 



2. 



