ON RECENT SPECIES OF SPIRASERPULA REGENHARDT, 1961 



53 



mation that the specimens belong to this species came from a 

 very small number of old and empty tubes at the bottom of 

 the aggregations having the characteristic serrated internal 

 dorsal ridge. The population had been subjected to oil 

 pollution, as evidenced by a thick deposit of it which covered 

 the tubes externally, and even lined them thinly internally. 

 worms: The longest operculate specimen (from lie Plane, 

 Marseille, BMNH ZB 1989 101-150) is 19.0 mm long; its 

 thoracic width 1.1 mm. It has 5 pairs of radioles, in addition 

 to an operculum on one side and a rudimentary operculum on 

 the other. It also has the longest operculum and peduncle, 

 3.5 mm; its operculum is 1.0 mm long, 1.2 mm in diameter, 

 bell-shaped, and with 11 rounded marginal lobes. The abdo- 

 men is 13.5 mm long and has 51 segments, the last four with 

 capillaries. The longest non-operculate specimen, from the 

 same locality, has a total length of 20.0 mm. Its abdomen is 

 15.5 mm long and has 43 segments, the last ten with capillar- 

 ies. The two specimens indicate variations in abdominal 

 length due to extent of contraction during fixation, and that 

 the number of segments in the abdomen may not be always 

 proportional to its length. In the other specimens studied, the 

 length of the operculum together with the stalk ranges from 

 1.0-2.0 mm; the operculum from 0.5-0.6 mm in length and 

 0.3-1.5 mm in diameter. 



The shape of the operculum varies from an elongate funnel 

 in the majority of cases to a narrow bell in the others (Fig. 4, 

 D, E).The opercular radii end in 10-16 rounded marginal 

 lobes. The width of the peduncle, just before the constriction, 

 is 3/5ths to 4/5ths that of the proximal end of the operculum. 

 The number of radioles observed is 4-6 pairs, and their 

 pinnule-free tips vary in length from l/5th to2/3rd the total 

 length of the radiole (i.e. radiole plus pinnule-free filament). 

 Zibrowius (1968) reported a higher maximum number of up 

 to 23 marginal lobes on the operculum. This high number, in 

 one specimen, is apparently not representative of the species 

 (Zibrowius, pers. comm.). 



A total of 67 specimens from different localities (including 

 21 from the abnormal Portman material, vide below) were 

 examined for various characters. All the Portman specimens 

 possess only rudimentary opercula. Out of 46 specimens from 

 the other collections 25 possess an operculum, 12 lack one, 

 and the rest are indeterminate since they lack radiolar 

 crowns. The majority of specimens from normal populations, 

 therefore, possess an operculum. 



Another character, hitherto not reported, is the presence 

 of two light red to reddish-brown clusters of prostomial ocelli 

 (Fig. 4, F). They can be seen when a worm with its radioles 

 removed is viewed from the anterior end, or through the 

 collar in mounted specimens. Each ocellus consists of a 

 pigmented cup-shaped part, and a transparent anteriorly or 

 antero-laterally directed lens-shaped part within it (Fig. 4, F). 

 Thoracic glands, as found in other species of the genus, are 

 absent. 



The numbers of thoracic chaetal tufts, 6 to 9 on each side, 

 may be symmetrical or asymmetrical. The condition in 26 



Table 1 Spiraserpula massiliensis (Zibrowius). Number of thoracic 

 chaetal tufts on each side. 



No. of individuals (n=26) 

 No. of thoracic chaetal tufts 



1 



6/7 



4 



7/7 



7 

 7/8 



11 



8/8 



3 

 8/9 



Table 2 Spiraserpula massiliensis (Zibrowius). Extent of the 

 thoracic membranes of the two sides. 



No. of individuals (n=21) 

 Thoracic membrane ends 



1 



2 



10 



2 



3 



3 



4/5 



4/6 



5/5 



5/6 



6/6 



6/7 



specimens is summarized in Table 1. Likewise, the thoracic 

 membranes may end symmetrically or asymmetrically, but 

 always anterior to the last thoracic chaetiger; an apron is, 

 therefore, absent (Fig. 4, E). The condition in 21 specimens 

 is given in Table 2. 



Collar fascicles bear 3 to 5 bayonet chaetae each. Bayonet 

 chaetae consist of a long serrated blade, an unserrated notch 

 of moderate length, and a basal boss with several teeth of 

 variable size (Fig. 3, G-J; PL 2, A). Thoracic and anterior 

 abdominal uncini usually have 4 or 5 teeth arranged in a 

 single row (edge saw-shaped), (Fig. 4, K, L; P1.2, B & C). In 

 the intermediate abdominal region, the edge of each uncinus 

 is saw-shaped anteriorly whereas several teeth are placed side 

 by side (edge rasp-shaped) posteriorly. The number of teeth 

 in a single row decreases and the rasp-shaped posterior 

 portion increases as the posterior end of the abdomen is 

 reached (Fig. 4, M-O). Although the posterior abdominal 

 uncini are rasp-shaped, they have a single large tooth anteri- 

 orly (Fig. 4, O). 



Live material. (Vide Zibrowius, 1968) 



Habitat and distribution. This species is commonly 

 found in submarine caves and at depths accessible by diving 

 (Zibrowius, 1968). The original description mentioned a 

 depth of 10-22m, but subsequently the species was found to 

 occur in shallower and deeper water (see list of material 

 examined). Deeper water collections came from depths of 

 31-36m (Tunisia) and 58-60m (off Point Elbow, Western 

 Sahara), the latter consisting of operculate and non- 

 operculate specimens. Empty tubes of this and other serpulid 

 species typical of shallow water have been obtained along the 

 the steep slope of the Gorringe Bank at 150-430m. This 

 occurrence may be due to slumping from shallower depths 

 (Zibrowius, pers. comm.). The Madeira Archipelago mate- 

 rial (125-145m) also consisted of dead material. The empty 

 tubes and single specimen from Canyon de la Cassidaigne 

 (170-200m) is also exceptional. In general, therefore, the 

 species commonly occurs in depths to about 60m, rarely down 

 to about 200m. 



S. massiliensis is common in the Mediterranean (Greece, 



Fig. 5 Spiraserpula capeverdensis sp. nov. A-P, From type locality (SW of Sao Vicente), CANCAP 6.148 & 6.146; A-L, From 6.148, M-P, 

 from 6.146. A, Opened tube showing serrated internal dorsal ridge along the convex wall of coiled part; and granular overlay in places. B, 

 Coiled part of tube with fine transverse growth wrinkles externally, and its fractured end showing dorsal ridge on convex inner wall, and 

 two ventro-lateral longitudinal rows of smooth tubercles on opposite wall. C & D, Cross-section of two tubes, both with serrated internal 

 dorsal ridge, and one with ventro-lateral rows of tubercles. E-G, Three views of same worm showing rudimentary opercula (F), condition 

 of the thoracic membranes (G), and dorsal longitudinal groove (E & G), and ventral abdominal groove posteriorly (E). H, Anterior end of 

 younger specimen. I-L, Bayonet collar chaetae, all from same fascicle. M, Thoracic uncini. N, Anterior abdominal uncini. O, Uncini from 

 transitional region of abdomen. P, Posterior abdominal uncini. 



