ON RECENT SPECIES OF SPIRASERPULA REGENHARDT, 1961 



89 



3830, BM(NH) 1993.17, AM W21677). 5. Boulton Reef, on 

 scleractinian coral (Thecopsammia regularis Gardiner 1899), 

 USNM 78572, dry material, legit J. C. Lang, 31.vii.1973. H. 

 Zibrowius, who identified this, kindly drew our attention to 

 its serpulid epifauna. 



Loyalty Islands, E. of New Caledonia: 6. SW Pacific Lagoon 

 of Beautemps-Beaupre Atoll; overhang 8 m, on heavily 

 encrusted dendrophylliid scleractinian coral, scuba diving, 

 dry material; MUSORSTOM 6 cruise, legit H. Zibrowius, 

 17.ii.1989. 



Okinawa (Japan): 7. W. side of Sesoko Island, 2-3 m, on 

 cliffside, in caves and grooves, scuba diving, on unidentified 

 coral, legit S. Nakamura, 10.i.l989, dry material, USNM . H. 

 Zibrowius kindly drew our attention to the serpulid epifauna. 

 Sinai (Egypt): 8. Strait of Tiran, at Sharks Observatory, 

 20-25 m; Nos. 210-213, legit H. A. ten Hove, 8.vi.l990 (2 

 specimens, tubes, HUJ, ZMA V. Pol. 3886). 

 Elat (Israel): 9. In front of Marine Biological Laboratory, 

 20-25 m, coral rubble; Nos. 154, a-d, legit H. A. ten Hove, 

 4.vi.l990. 10. Oil port, S. pier, 6-25 m, coral rubble and 

 pillars of pier; Nos. 181,244, 311, 339, 340, legit H. A. ten 

 Hove, 6.vi.l990 (3 specimens, several tubes, HUJ). 



Type locality. Taka Bone Rate (Flores Sea, Indonesia). 



Description. 



TUBES: Mustard coloured, with a pair of darker longitudinal 

 bands in places along each flank, joined by transverse bands, 

 especially just anterior to the thickenings found at intervals 

 (Fig. 26, A,C). They may be coiled more or less parallel to 

 one another in the horizontal plane, mutually bonded 

 together or spread out on the substratum and branched in 

 places. Their external diameter is quite small, only up to 

 about 0.6 mm. Earlier formed portions of tubes may show 

 narrow transverse wrinkles (Fig. 26, B,D). In fresh material 

 the colour of the tube may be more brownish, and appears to 

 fade to mustard after a few months in alcohol. 



ITS consist of an unserrated ventral ridge only (Fig. 26, 

 B,E-I), which is T-shaped in cross-section towards its middle 

 (Figs. 26, G, I; 3, F), and becomes progressively less thickened 

 both anteriorly and posteriorly (Fig. 26, E,I). 

 worms: The total length of the worms ranges from 2.2 mm in 

 the case of a juvenile, to a little more that 12.3 mm in an 

 older individual which lacks its radioles. The complete holo- 

 type (Fig. 26, J) is only 5.8 mm long. The thoracic width in all 

 the specimens is around 0.3 mm. 



An operculum may or may not be present. Younger 

 specimens have radioles but lack opercula (Fig. 26, L,M); 

 apparently opercula appear only in older worms (Fig. 26, 

 A,J,K). The length of the operculum and peduncle in the 

 holotype is 1.5 mm, the operculum 0.3 mm long and its 

 diameter 0.2 mm. Its distal part is nearly globular 

 (Fig.26,A,J,K) and, unlike the opercula of the other known 

 members of the group, its margin is not divided into lobes, 

 but shows about four pseudo-lobes, apparently caused by 

 contraction in alcohol. Its proximal part is shaped like a 

 narrow funnel, separated by a sharp constriction from the 

 slender peduncle. A short filamentous rudimentary opercu- 

 lum was observed in one specimen only. It appears likely 

 that, like the operculum, they are developed in older worms. 

 Pinnule-free tips of radioles short. Thoracic glands were not 

 found. Some counts and meristic data are given in Table 20: 



The abdominal length in eight specimens ranged between 

 11.2 and 1.0 mm, and the number of segments between 48 



Table 20 S. snellii sp. nov. Some meristic and other data of type 

 series. 



No. of specimens (n=6) 

 No. of radioles 



3 



5/5 



3 



4/4 









No. of specimens (n=8) 

 No. of thoracic chaetal tufts 



2 

 8/7 



1 

 8/6 



2 



7/7 



2 

 7/6 



1 



7/5 



No. of specimens (n=3) 

 Thoracic membrane ends 



1 



4/4 



1 



4/3 



1 



3/3 







and 22, respectively, with capillaries on the last 6 or 7. 



Collar fascicles of older specimens bear about four fully 

 formed bayonet chaetae and a developing one deep within. 

 Each bayonet chaeta possesses a long serrated blade, a 

 moderately long unserrated notch (1/3-1/4 the length of the 

 entire blade), and several teeth on the basal boss (Fig. 26, 

 N-U; PI. 5, F). Thoracic uncini (Fig. 26, V,W) and anterior 

 abdominal uncini (Fig. 26, X; PI. 5, G) bear 4-6 and 4-5 teeth, 

 respectively, in a single row. Flat trumpet-shaped chaetae are 

 typical (PI. 5, H). 



Remarks. One single tube revealed 2 specimens: a parent 

 with schizont closely appressed to its posterior end. Posteri- 

 orly, the abdomen of the parent was abruptly tapering 

 (dorso-ventrally), with long capillaries. Lying between those, 

 the three pairs of radioles of the schizont could be found. It 

 had a narrow, still not fully developed thorax with 7/6 chaetal 

 tufts, followed by a well-formed abdomen with 17 chaetigers 

 (the last 7 with capillaries). The entire schizont was folded 

 over the ventral internal ridge. 



Collections from other localities. The specimens in 

 sample 2 from Queensland agree with those in the Indonesian 

 sample with regard to the overall mustard colour. Against 

 this background colouration there are darker mustard to 

 brown longitudinal bands, which are variable. One of the 

 three available tubes has a pair of lateral longitudinal bands, 

 lacking in places. The second tube has a thin median longitu- 

 dinal stripe in addition. The third has a pair of mustard yellow 

 longitudinal bands laterally, and a broad brownish median 

 band which is partially divided into two bands by a narrow, 

 yellow longitudinal band. 



They are coiled upon themselves either individually or 

 mutually bonded together. The coils are more or less concen- 

 tric, low, flattened against the substratum, and bonded 

 together (Fig. 27, A). The maximum external tube diameter is 

 1.2 mm. The granular overlay consists of a median longitudi- 

 nal band made up of broad, transverse, forwardly-directed 

 scutes, and a narrow band of smaller granules laterally 

 (Fig. 27, A). At irregular intervals there are wavy, thickened, 

 peristome-shaped transverse ridges. 



ITS agree with those of the Indonesian specimens. They 

 consist of only an unserrated ventral ridge. Its edge is smooth 

 and, in cross-sectional appearance, varies from being wedge- 

 shaped to thickened and T-shaped at its maximal develop- 

 ment (Fig. 27, B). The cross-bar of the T may also be curved 

 outwards and bear a shallow longitudinal depression. The 

 mid-ventral longitudinal abdominal groove is applied to this 

 ridge. 



Three worms were removed from the tubes. One has a 

 damaged thorax and an incomplete abdomen, while the 

 second lacks the radioles of both sides, the third is broken in 4 

 fragments. The former (Fig. 27, D), is 0.4 mm wide in the 



