Synelmis britayevi, Salazar-Vallejo, 2003

Salazar-Vallejo, Sergio I., 2003, Revision of Synelmis Chamberlin, 1919 (Annelida, Polychaeta, Pilargidae), Zoosystema 25 (1), pp. 17-42 : 23-24

Synelmis britayevi n. sp.

( Figs 1A ; 3 )

TYPE MATERIAL. — Syntypes: SE Mozambique Channel, Walters Shoal, International Indian Ocean Expedition, Anton Bruun, cruise 7, stn AB 381 A, grab sampler, 33°13’S, 43°51’E, 46 m, 30.VIII.1964, 7 syntypes ( LACM-AHF- 2092).

TYPE LOCALITY. — Mozambique Channel.

ETYMOLOGY. — This species in named for Dr Temir A. Britayev, in recognition of his many publications on polychaetes and polychaete commensalism and especially for his research on pilargids.

OTHER MATERIAL EXAMINED. — Southwestern Indian Ocean. SE Mozambique Channel, Walters Shoal, 33°13’S, 43°51’E, International Indian Ocean Expedition, Anton Bruun, cruise 7, stn AB 381 B, rock dredge, 30.VIII.1964, 36- 40 m, 10 specimens (LACM-AHF).

DISTRIBUTION. — Apparently restricted to the Mozambique Channel.

DESCRIPTION

Body filiform, variously pigmented from pale to dark red or purple probably due to Rose Bengal staining; pigment more intense on sides of body and ventrally in paired darker glands. Specimens 4.0- 20.5 mm long, 0.3-1.0 mm wide, with 32- 92 setigers.

Prostomium rectangular with biarticulated palps well separated from each other, palpostyles rounded, massive, with small ventrolateral papillae. Three similar fusiform antennae, lateral antennae located at middle of prostomium, median placed on posterior margin, very short, not reaching setiger 1 ( Fig. 3A ). Two well developed eyes, medial to and slightly behind lateral antennae. Of 17 specimens, nine had two well developed eyes, two had one eye duplicated, two had both eyes duplicated, one had one eye split into three eyespots but not arranged in a line, and in two specimens eyes could not be seen. Two pairs of tentacular cirri, the dorsal one slightly longer than the ventral one and as long as dorsal cirri of setiger 1.

Parapodia with slender fusiform cirri, never thicker than setal lobe. Dorsal cirri and ventral cirri similar in length or ventral cirri slightly shorter. Glandular areas well developed posteri- or to setal lobe region; starting from setiger 2-3, glands become bigger and better developed posteriorly, continue to end of body; appear circular in frontal view, contain transverse rods. No interramal glands but paired glandular areas ventrally in posterior setigers. Anterior parapodia with setal lobe about half the length of ventral cirri ( Fig. 3B ). Median ( Fig. 3C ) and posterior parapodia similar ( Fig. 3D ) though ventral cirri become usually slightly longer posteriorly.

Notospines slightly emergent even in posterior parapodia; usually first present from setigers 13-18; variation in first occurrence slightly dependent on body size or due to regeneration of specimens (one anteriorly regenerating specimen with 32 setigers had notospines from setiger 6; another one with 54 setigers had notospines from setiger 10). Neurosetae include smooth capillaries, limbate setae, and one or two symmetrical furcate setae per setal bundle ( Fig. 1A ).

Pygidium with two lateral anal cirri, as long as previous two asetigerous segments ( Fig. 3E ). Pharynx can be as long as four to nine setigers.

REMARKS

Synelmis britayevi n. sp. resembles S. harrisae n. sp.; their main difference is that the former has well developed lateral glands behind setal lobes while the latter lacks such glands. The wide range of first occurrence of notospines due to regeneration may lead to misidentifications. One specimen was regenerating its anterior end but it had already spines in the anteriormost setiger which could be quite misleading. Most specimens (three exceptions) had the first notospines between setigers 10-17. This should be reevaluated with specimens without regeneration.

Figures

FIG. 1. — Furcate setae from different Synelmis species; A, S. britayevi n. sp. (LACM-AHF-2092); B, S. emiliae n. sp. (UANL-318); C, S. gibbsi n. sp. (BMNH-1971.65); D, E, S. gorgonensis (Monro, 1933) n. comb.; D, BMNH-1932.12.24.128; E, ZMH-14211; F, S. harrisae n. sp. (LACM-AHF-2095); G, S. rigida (Fauvel,1919) n. comb.(BMNH 1970.310); H, S. rigida n. comb. (MNHN A71); I, J, S. sotoi n. sp. (MNHN A888 As296). Scale bar: 30 µm.

FIG. 3. — Synelmis britayevi n. sp. from the Mozambique Channel (LACM-AHF-381B); A, anterior end in dorsal view; B, setiger 5 in posterior view (LACM-AHF-2092); C, setiger 19 in posterior view; D, setiger 45 in anterior view; E, posterior end in dorsal view. Scale bars: A, E, 0.22 mm; B-D, 50 µm.