Polaruschakov reyssi Pettibone 1976

Polaruschakov reyssi

Macellicephala arctica.—Reyss, 1968:323 [part]; 1971:244 [part].—Levenstein, 1972:172 [part; not Knox, 1959].

Macellicephala (Sinantenna) arctica.—Hartmann-Schröder, 1974:81 [part; not Knox, 1959].

MATERIAL EXAMINED.—Mediterranean, submarine canyon off Banyuls-sur-Mer, Rech Lacaze-Duthiers, 42°28′N, 03°28′E, 750 m, sta. EP 5, D. Reyss, collector, holotype (USNM 52225; exchange from COB).

DESCRIPTION.—Length of holotype 14 mm, width with parapodia 4 mm, width with setae 6 mm, segments 23, last one very small. Body and parapodia with patches of black pigment. Prostomium cordiform, with shallow anterior notch; palps long, tapering, smooth; without eyes (Figure 33a). All but right dorsal tentacular cirri missing or broken; style long, tapering, smooth, shorter than palps. Without distinct facial tubercle but with somewhat lobulated upper lip (Figure 33a,b). Paired scalelike lobes on segment 6, wide, thickened, soft, elongate-oval (Figure 33a). Notosetae moderate in number on anterior five setigerous segments, few or lacking more posteriorly (Figure 33a,c,d). Notosetae slender, tapering to capillary tips, with spinous rows (Figure 33e). Neurosetae slender, slightly stouter than notosetae, transparent, iridescent, flattened distally, spinous along lateral borders, with bare, slightly tapered, blunt tips (Figure 33f). Styles of dorsal cirri all missing, except for left parapodium of segment 3 (Figure 33a). Dorsal tubercles on cirrigerous segments inconspicuous. Nephridial papillae indistinct.

ETYMOLOGY.—The species is named for Dr. Daniel Reyss, who collected the holotype and presented it to the Smithsonian Institution.

DISTRIBUTION.—Mediterranean, in 750 meters.

BATHYMACELLINAE, new subfamily

TYPE-GENUS.—Bathymacella, new name for Macella Averincev, 1972, preoccupied.

Averincev (1972:111) placed his new genus Macella close to Macellicephala McIntosh, Macellicephaloides Uschakov, and Macelloides Uschakov. The distinguishing character that separated Macella from the other three genera was the complete absence of chitinous jaws on the pharynx. Hartmann-Schröder (1974:75, 81, 85) placed Macella, along with the other three genera, in the subfamily Macellicephalinae.

Based on a study of the paratype of the type-species of Macella, M. uschakovi, it was noted that lateral prostomial antennae were present, not absent, as indicated by Averincev in his original description. The ceratophores of the lateral antennae are small, rounded, and inserted ventrally to the large ceratophore of the median antenna; these structures were referred to as lateral prostomial horns by Averincev. The styles of the lateral antennae were missing but their places of attachment were observed. The presence of lateral antennae and their ventral insertion would place Bathymacella closer to the Harmothoinae, rather than the Macellicephalinae. The parapodia and setae of Bathymacella, however, differ from that found in both subfamilies.

The unique feature of the new subfamily is the structure of the pharynx, indicated by the complete absence of jaws. The opening of the pharynx is encircled with pleated folds, not distinct papillae, as generally found in the Polynoidae.

At present, the subfamily Bathymacellinae is represented by the type-species, Bathymacella uschakovi (Averincev), endemic in the deeper waters of the Antarctic.

Macella Averincev, 1972, preoccupied by Macella Walker, 1858, in Lepidoptera, and by Macella Stål, 1875, in Orthoptera [see Neave, 1940:2].

TYPE-SPECIES.—Macella uschakovi Averincev, 1972. Gender: feminine.

DIAGNOSIS.—Body flattened, fusiform, with short, thick parapodia; segments 18 (first achaetous). Elytra and prominent elytrophores 9 pairs, on segments 2, 4,5, 7, 9, 11, 13, 15 and 17; elytra round, transparent, without tubercles or papillae. Dorsal tubercles on cirrigerous segments large, nodular. Prostomium subtriangular, bilobed; median antenna with large ceratophore in anterior notch, with short style; lateral antennae with small ceratophores ventral to ceratophore of median antenna (styles missing); palps small, subcorncal, ventral to cirrophores of tentacular cirri; without eyes. First or tentacular segment fused to prostomium, not visible dorsally, with two pairs of tentacular cirri lateral to prostomium, with large cirrophores and short styles, without acicular lobes or setae; without facial tubercle. Segment 2 with ventral buccal cirri longer than following ventral cirri, attached to basal parts of parapodia, posterolateral to mouth. Parapodia biramous; notopodia low, rounded, with digitiform acicular lobes on lower side; neuropodia deeply cut dorsally and ventrally, forming diagonally truncate, longer presetal and shorter postsetal rounded lobes. Notosetae more slender than neurosetae, with spinous rows and blunt tips. Neurosetae more slender (upper ones) and stouter, with slightly hooked bare tips and spinous rows. Dorsal cirri with short cylindrical cirrophores and short, tapering styles; ventral cirri short. Pygidittm rounded, posterior to last segment, with pair of anal cirri. Pharynx without distinct papillae, without jaws.

The genus is monotypic, represented by the type-species: Bathymacella uschakovi (Averincev), as Macella uschakovi Averincev, 1972; Australian-Antarctic, north of Davis Sea, in 4540 meters.