Serpula cf. vermicularis

Bastida-Zavala, Rolando, 2012, Serpula and Spiraserpula (Polychaeta, Serpulidae) from the Tropical Western Atlantic and Gulf of Guinea, ZooKeys 198, pp. 1-23 : 8-9

Serpula cf. vermicularis Figs 1 E–F2H–J 56

Material examined.

Nigeria. Five specimens (UMML 22.545), RV Pillsbury, sta. 248, Southeast of Lagos, 4°05'N, 5°40'E, 10-foot try-net, 33 m, May 13, 1965.

Description.

Tubes missing. Body light brown (preserved material only). TL= 18.5 mm (n=4, r:9.4-18.5, µ =36.6 ± 10.3); THW= 1.7 mm (n=5, r:1.2-1.7, µ =1.6 ± 0.2). Thoracic membranes and opercular peduncles of all the specimens damaged. Branchial crown with 27 radioles (n=4, r:19-27, µ =23.8 ± 3.4) left, and 25 right (n=4, r:17-25, µ =22.5 ± 3.7); lacking inter-radiolar membrane.

Peduncle smooth, with insertion on left (n=2) or right (n=2); lacking constriction between it and operculum, its position represented only by a slight change in color (Figs 1E, 2I). Club-shaped pseudoperculum present in all specimens.

Operculum with short, shallow symmetrical funnel; lacking bulbous basal part (Figs 1E, 2I). OL= 2 mm (n=4, r:1.3-2.1, µ =1.9 ± 0.4), OD= 1.8 mm (n=4, r:1.1-1.8, µ =1.6 ± 0.3). Interradial grooves 1/4 of funnel length (Fig. 2H). Funnel with up to 39 radii (n=4, r:33-39, µ =36.3 ± 3.2) with blunt tips (Fig. 1 E–F). Opercular inner surface lacking tubercles (Figs 1 E–F, 2I).

Collar thick, with ventral and dorsal lobes short. Thorax consists of seven chaetigers. Collar chaetal fascicles symmetrical with regard to size and composition unlike in Serpula vossae sp. n. Bayonet chaetae with two blunt-elongate teeth, distal blade smooth, lacking proximal rasp (Fig. 2J); hooded (capillary) chaetae present.

Thoracic membranes apparently well developed (membranes damaged), narrowing toward posterior thorax, fused ventrally, forming a short apron. Remaining six thoracic chaetigers with hooded (limbate) chaetae of two sizes; saw-shaped uncini.

Abdomen with anterior achaetous region. Anterior and middle abdominal chaetigers with flat-trumpet chaetae. Posterior chaetigers with ‘capillary’ chaetae. Anterior and posterior uncini saw-shaped.

Variation.

Two specimens with a hyaline circle in radii tip (Fig. 1F). One specimen with few inconspicuous tubercles in interior funnel surface.

Distribution.

Nigeria, Gulf of Guinea (Fig. 6).

Ecology.

Sublittoral, 33 m.

Remarks.

Serpula cf. vermicularis resembles the nominal species; unfortunately, the tubes of all the specimens are missing. There are some differences with the nominal species, particularly with regard to the number of radii: Serpula cf. vermicularis has 33-39 opercular radii (Fig. 1F, 2I, 5), while Zibrowius (1968) recorded specimens from Marseille with more than 40 opercular radii, and Kupriyanova and Jirkov (1997) recorded specimens from Norway and Iceland with a mean of 50.8 opercular radii; and the proximal rasp of the bayonet chaetae: Serpula cf. vermicularis lacks a proximal rasp (Fig. 2J), while Rioja (1931) and Kupriyanova (1999, Table 1) mentioned that their specimens have a proximal rasp.

Zibrowius (1973) recorded several specimens as Serpula vermicularis , from Western Africa (from Angola to Morocco); unfortunately the description was too brief and did not included figures; however, Zibrowius (1973) mentioned that the specimens that he reviewed showed considerable variation.