100 



T.G: PILLAI AND HA. TEN HOVE 



synonymized Pseudoserpula rugosa Straughan, 1967, with 

 Crucigera inconstans Straughan, 1967, stating that the type of 

 Pseudoserpula is a pseudoperculate individual of C. incon- 

 stans, but the evidence was incomplete. Moreover, there still 

 remained the problem of the actual generic identity of P. 

 minuta Straughan, 1967. Hence it was considered necessary 

 to re-examine the types of P. rugosa and P. minuta and 

 compare them with other collections, including those of 

 Crucigera inconstans. 



The holotype of the nominal species Pseudoserpula rugosa 

 (AM W4027) yielded the following data: The tube is white, 

 2.0 mm in external diameter, and has conspicuous transverse 

 wrinkles (Fig. 33, A-C). It lacks ITS. An operculum is absent, but 

 a rudimentary operculum is present on each side (Fig. 33, C). An 

 apron is present (Fig.33,B). The bayonet chaetae typically 

 possess two conical teeth on the basal boss, as seen in developing 

 chaetae deep inside the fascicle (Fig. 33, H, I); one of the conical 

 teeth may be smaller than the other or abraded in the older 

 chaetae (Fig. 33, D-F). A short, unserrated notch is present; the 

 chaetal shaft is smooth below the teeth. 



Additional material of Crucigera inconstans (NSW, Sandy 

 Beach, 21 km N. of Coffs Harbour, legit H. A. ten Hove, 

 27.iv.1986, Stn. 38 [8 specimens, ZMA V. Pol. 3741] and 

 Sydney, Long Reef, intertidal rockpools, legit H. A. ten 

 Hove and P. Hutchings, 29.iii.1986, Stn 30. [lspecimen, 

 ZMA V. Pol. 3740]) gave the following data: The tube is 

 smooth and has transverse wrinkles (Fig. 33, J). Only three 

 specimens, two from Sandy Beach and one from Long Reef, 

 possess opercula; the remaining five only rudimentary oper- 

 cula. The opercula (Fig. 33, J-L, S-V) agree fully with 

 Straughan's description and figures of C. inconstans. The 

 bayonet collar chaetae (Fig. 33, M-P) agree with those of the 

 holotype of Pseudoserpula rugosa. The rudimentary opercula 

 show different stages of development: both club-shaped, with 

 somewhat tapering ends in the holotype (Fig. 33, C); one long 

 and tapering, the other more bulbous (Fig. 33, W); and a 

 clearly developing operculum (Fig. 34, A). While the holo- 

 type of Crucigera inconstans has 10 or 11 pairs of radioles 

 (Straughan, 1967), an operculate individual in our material 

 shows 15/16. The bayonet chaetae (Fig. 34, D-M) are similar, 

 although they may occasionally possess a small third tooth 

 (Fig. 34, J). A well developed apron is present in non- 

 operculate and operculate specimens (Fig. 34, B), and in the 

 holotype of P. rugosa (Fig. 33, B). 



Some of the specimens bearing rudimentary opercula have 

 regenerating radioles and/or operculum, which appear to have 

 been nipped off on one side or the other (Figs. 33, W; 34, C). In 

 one of the operculate specimens too some of the radioles are 

 regenerating (Fig. 33, J). It appears, therefore, that opercula and 

 radioles in Crucigera inconstans are favoured as food by certain 

 predators. Whether this is the sole reason for a large number of 

 specimens possessing only rudimentary opercula or not, has to be 

 determined through further studies. It is worth noting, however, 

 that the radioles of both sides in the holotype of Pseudoserpula 

 rugosa are disproportionately small for the size of the worm, and 

 show every indication of being in a state of regeneration (Fig.33, 

 B,C). 



Meanwhile, Pseudoserpula minuta Straughan, 1967, lacks 

 an apron and has ITS and, therefore, belongs to the genus 

 Spiraserpula Regenhardt, 1961. 



Another nominal genus, Protoserpula Uchida, 1978, needs 

 to be discussed. Its original description does not mention if 

 and where any material has deposited. It is not in the 

 National Science Museum, Tokyo, and other efforts to obtain 

 it were unsuccessful. Among the generic characters men- 

 tioned are the following: An operculum is absent, the number 

 of thoracic chaetigers is 9 or 10, and capillary chaetae are 

 absent towards the posterior end of the abdomen. The latter 

 is emphasized in the statement 'All the species of Serpula and 

 its related genera have their long hair-like abdominal poste- 

 rior segments, but the new genus has not such kind of setae in 

 abdomen' (Uchida, 1978: p. 23). 



The more important characters described under P. paci- 

 fica, the type species, are as follows: 'Tube calcareous white 

 opaque, cylindrical form, attached throughout its length, 

 curved irregularly . . Operculum absent. Branchiae consist- 

 ing of 5 pairs of filaments and a pair of palpi. . . The 

 ventral-most one pair of branchiae are much reduced (0.3mm 

 long). . . The thoracic membrane developed in the anterior 

 region but suddenly reduced in width from the 5th segment, 

 and it becomes to continue to the abdominal body surface 

 without any structures in the last thoracic segment. Abdomen 

 . . . consisting of about 20 setigerous segments, 2.5 mm long 

 and 0.2 mm wide. . . Bayonet-shaped seta has a basal process 

 with about 8 large teeth arranged into a circle. . . Each 

 abdominal segment has 1-3 spatulate setae and 8-11 uncini 

 on one side. . . The spatulate setae arranged to the last 

 setigerous segment, and without substitution to the long 

 hair-shaped setae as occurred in every species in Hydroides. 

 Serpula, Vermiliopsis, and other many genera' (Uchida, 

 1978, p.23-24). 



Protoserpula appears to be based on a juvenile serpulid 

 (ten Hove, 1984, p. 193). A juvenile specimen would not be 

 sound for erecting a genus since the adult characters could be 

 different, particularly with regard to the presence or absence 

 of an operculum. 



In the development of operculate serpulids, the operculum 

 appears after a certain number of radioles have already been 

 formed (ten Hove 1984, p. 183, and Fig. 3). This appears to be 

 in keeping with the greater importance of feeding and respi- 

 ration over closure of the tube against predators at this stage. 

 The dorsalmost pair of radioles remains simple and palp- 

 shaped, and forms the lateral appendages of the dorsal lip 

 (mouth palps). In this process they may decrease in size. The 

 operculum develops as a modification of the second most 

 dorsal radiole of one side. 



As seen from the species of Spiraserpula described in this 

 account, some possess an operculum, some may or may not 

 possess one, and others lack one but possess a rudimentary 

 operculum on each side. Some agree with regard to the 

 number of radioles, but none of them show palps. 



It appears unlikely that rudimentary opercula ( = pseudo- 

 percula) were mistaken for 'a pair of palpi' since, in the 

 same paper, Uchida clearly distinguishes between pseudo- 



Fig. 33 Crucigera inconstans Straughan, 1967. A-I, From holotype of Pseudoserpula rugosa Straughan, 1967, with only rudimentary 

 opercula. A, Anterior part of tube. B & C, Worm within posterior part of tube, showing apron (B), presence of rudimentary opercula 

 (=pseudopercula, C). D-I, Bayonet chaetae. J-W, Crucigera inconstans Straughan, 1967 from Long Reef, Sydney. J & K, Operculate 

 specimen within its tube and three views of its operculum. M-R, Bayonet chaetae from same fascicle, M & N newly formed deep within 

 fascicle. S & T, Two views of small operculum. U & V, Two views of large operculum. W, Anterior end of large non-operculate specimen 

 with two rudimentary opercula. 



