Bathyvermilia kupriyanovae, Bastida-Zavala, 2008

Bastida-Zavala, J. Rolando, 2008, Serpulids (Annelida: Polychaeta) from the Eastern Pacific, including a brief mention of Hawaiian serpulids, Zootaxa 1722, pp. 1-61 : 14-16

Bathyvermilia kupriyanovae sp. nov.

( Figures 3A–O)

Type locality: 34º41’N, 123º8’W, 220 km off California, USA .

Material examined. Fourteen specimens (more 6 by H.A. ten Hove): California ( USA), LACM-AHF Poly 2181, holotype; LACM-AHF Poly 2182, 13 paratypes, ZMA V.Pol. 3863, 6 paratypes (34º41’N, 123º8’W, 220 km off California, R / V New Horizon, cruise Pulse 2, sta. 224M, otter trawl, on stalks of glass sponges, 4,100 m, Oct. 30, 1989, coll. K.L. Smith) .

Description. Tube white, ID=2.5 mm (n=6, r:0.9–2.5, µ=1.8±0.5), ED=3.5 mm (n=6, r:1–3.8, µ=2.7±1), circular in cross section; surface smooth, very shining, almost polished, and slightly transparent; up to eight wide peristomes (n=5, r:3–8, µ=6±2.3) throughout length of tube, distance between peristomes decreases towards distal end of tube. Tube lacks longitudinal ridges or alveoli ( Fig. 3C). Tubes attached to sponge spicules throughout their length (some tubes with anterior end unattached).

Colour and size: body pale yellow. TL=19.3 mm (n=4, r:(1.7)12.8–19.3, µ=16.5±2.7).

Branchial crown: with 25 radioles (n=5, r:11–25, µ=19.8±5.9) on the left, and 26 on the right (n=5, r:10–27, µ=20.2±7). RL=7.5 mm (n=5, r:(0.6)3–7.5, µ=5.4±1.7). Radioles not connected by an interradiolar membrane, terminal filaments short. Pinnules long. Dorsal lip of mouth with pair of up to 0.2 mm long finger-like palps, ventral lip crenulated (observation by H.A. ten Hove).

Peduncle: POL= 8 mm (n=5, r:(0.7)3.2–8, µ=5.7±1.9), three times thicker than radioles. Insertion left (n=2) or right (n=3), within line of normal radioles; smooth, with very marked constriction ( Figs 3A, D). Two peduncles annulated distally ( Fig. 3E). Lacks pseudoperculum.

Operculum: OL= 2 mm (n=5, r:(0.25)0.9–2.2, µ=1.6±0.5), OD= 2 mm (n=5, r:(0.15)0.9–2.0, µ=1.6±0.5). Operculum as shallow funnel, with basal membranous section and chitinous-calcareous distal plate, yellowish white, varying from slightly concave ( Fig. 3A) to deeply concave in most specimens ( Figs 3D–E). Distal plate of some specimens with concentric and radial lines ( Figs 3B, E).

Collar: short, reaches the base of the radioles, not incised ventrally or laterally. Collar with hooded (limbate) chaetae of two sizes ( Figs 3F–G).

Thorax: THL= 3 mm (n=5, r:(0.6)1.7–3.5, µ=2.9±0.7), THW=1.1 mm (n=5, r:(0.1)0.5–1.5, µ=1±0.4). Thoracic membrane short, reaches to 4 th chaetiger, wider extends to second chaetiger and then narrowing sharply. Six chaetigers with hooded (limbate) chaetae ( Fig. 3H); ” Apomatus ” chaetae present from third chaetigers onwards ( Fig. 3I); saw-shaped uncini ( Figs 3L–M) with 7 teeth including anterior fang.

Abdomen: with short achaetiger region followed by 66 (n=4, r:(7)51–77, µ=62±11.9) chaetigers. Anterior and middle chaetigers with almost straight geniculate chaetae ( Figs 3J–K). Posterior chaetigers with “capillary” chaetae. Uncini saw-shaped, with two rows of teeth ( Figs 3N–O), 5–6 teeth in lateral view. Abdomen with two terminal anal cirri.

Habitat. Depth: 4,100 m. Bathyal. On stalks of glass sponges of the genus Hyalonema and artificial stalks, co-occurring with Hyalopomatus mironovi (cf. Beaulieu 2001a –b).

Distribution. North-eastern Pacific. Off California ( USA) (34º41’N, 123º8’W).

Etymology. Named after Elena Kupriyanova (presently The University of Adelaide), for her remarkable dedication to the taxonomy and biology of the serpulids.

Taxonomic remarks. Bathyvermilia kupriyanovae n. sp., is similar to B. zibrowiusi Kupriyanova, 1993 because it has a tube with peristomes and thoracic membrane extends to 4 th chaetiger. However, B. kupriyanovae n. sp., differs from B. zibrowiusi in having concentric convex plate (as depicted in Kupriyanova’s figure 2c) with several concentric ridges (as stated in her description, Kupriyanova 1993: 24), while B. kupriyanovae n. sp., has only one chitinous-calcareous plate, slightly concave in the holotype ( Fig. 3A) and more concave in the rest of the specimens ( Figs 3D–E). The former species has an operculum with smooth sides, while B. kupriyanovae n. sp., has the ventral side wrinkled in all specimens ( Figs 3A, D–E). Also, in B. kupriyanovae n. sp., the opercular peduncle is three times thicker than the radioles, while in B. zibrowiusi it is 1.5 times thicker than the radioles. Bathyvermilia zibrowiusi was described from only one specimen, collected from Kurile Trench (depth 4,550 m). Another species of Bathyvermilia , B. challengeri Zibrowius (1973) , was described from Mid-Pacific (depth 4,346 –5,719 m) based on two incomplete specimens and several tube fragments, and differs from B. kupriyanovae n. sp., as the tube of the former species is subquadrangular in cross section, while in B. kupriyanovae n. sp., it is circular; also, B. challengeri has many (22 in Zibrowius Fig. Id) smooth transverse ridges not encircling completely the tube, different to the less numerous (3–8) true peristomes present in B. kupriyanovae n. sp.; the opercular plate is slightly convex in B. challengeri , while it is concave in B. kupriyanovae n. sp.; the number of radioles is 12 in each lobe in B. challengeri , while there is a mean of 19 and 20 radioles in left and right lobes in B. kupriyanovae n. sp.; the thoracic membrane extends to second chaetiger in B. challengeri , while in B. kupriyanovae n. sp., it extends to the fourth thoracic chaetiger.

Remarks. The holotype has several foraminifera incrusting the distal plate ( Figs 3A–B); other specimens have small tubes of the same species on the distal plate. Bathyvermilia kupriyanovae n. sp., is the most abundant metazoan present on the stalk communities of the sponge Hyalonema ( Beaulieu 2001b) .