Bathyeliasona kirkegaardi (Uschakov 1971)

Bathyeliasona kirkegaardi (Uschakov)

Macellicephala abyssicola.—Kirkegaard, 1956:64 (part?) [not Fauvel, 1913].

Macellicephala kirkegaardi Uschakov, 1971:37, figs. A–E.—Levenstein, 1971b:24, 30, fig. 4b [part]; 1972:172 [part]; 1973:129.—Reyss. 1971:251.—Hartmann-Schröder, 1975:53. figs. 9–15.

Macellicephala (Macellicephala) kirkegaardi.—Hartmann-Schröder, 1974:76, 84.

MATERIAL EXAMINED.—Southwest Pacific, Kermadce Trench, 32°20′S, 176°54′W, 6620 m, Galathea sta. 650, 31 December 1952, 1 specimen (USNM 51972; exchange from UZMC; as M. abyssicola by Kirkegaard, 1956).

North Pacific, Aleutian Trench, 52°26′N, 170°54′E, 7180 m, Vitiaz sta. 3357, 1955, paratype (ZIASL 13757). 51°09′07″N, 174°35′E, 7250 m, Vitiaz sta. 6145, 1969. 1 specimen (USNM 51970; exchange from IOASM; reported by Levenstein, 1971b).

Northeastern Atlantic, off Portugal, 42°10.7′N, 14°20.8′W. 5275 m, Meteor 3, sta. 38, 19 March 1966, Thiel, collector, 2 specimens (USNM 52071; exchange from ZMH; reported by Hartmann-Schröder, 1975).

DESCRIPTION.—Length of paratype (ZIASL 13757) 50 mm, width with parapodia 30 mm, segments 17. Length of specimen from Vitiaz sta. 6145 (USNM 51970) 47 mm, width with parapodia 23 mm, segments 17. Length of specimen from Kermadec Trench (USNM 51972) 38 mm, width with parapodia 20 mm, segments 17.

Bilobed prostomial lobes rounded, with minute filiform frontal filaments; ceratophore of median antenna long, cylindrical, with style long, tapered, with minute papillae; palps very long, smooth, extending to about segment 8 (Figures 15a,b, 17a; Uschakov, 1971, fig. A; Hartmann-Schröder, 1975, fig. 9). Tentacular parapodia with conical projecting acicular lobe and truncate setigerous lobe with transverse row of notosetae (up to 14); styles of tentacular cirri long, slender, with minute clavate papillae (Figures 15a, 17a; Uschakov, 1971, fig. A; Hartmann-Schröder, 1975, fig. 9).

Parapodia typical (Figures 15c, 16a,f, 17b,c; Uschakov, 1971, fig. B; Hartmann-Schröder, 1975, fig. 12). Neuropodia of posterior segments longer than notopodia, similar to more anterior parapodia (Figure 15f,g; Uschakov, 1971, fig. C; Hartmann-Schröder, 1975, fig. 11). Notosetae moderate in number (up to 20), variable in length and width, with numerous spinous rows and blunt bare tips (Figures 15d, 16b,d, 17d Uschakov, 1971, fig. D; Hartmann-Schröder, 1975, fig. 13). Neurosetae of segment 2 not as wide as on following segments (Figure 15e). Neurosetae very wide, with serrated lateral margins (Figure 16c,e, 17e; Uschakov, 1971, fig. E; Hartmann-Schröder, 1975, fig. 14).

Pygidium enclosed in parapodia of segment 17, with posterior paired subconical anal lobes (Figure 15f,g; Uschakov, 1971, fig. C; Hartmann-Schröder, 1975, fig. 11). Female specimen from Aleutian Trench (USNM 51970) with grapelike bunches of small eggs; large bubble-like eggs free in body cavity, 1–2 mm in diameter, with transparent, thin, tough, flexible membranes and filled with oil globules.

DISTRIBUTION.—North Pacific (Aleutian Trench), Southwest Pacific (Kermadec Trench), Indo-Pacific (Sunda Trench—Kirkegaard), Northeastern Atlantic (off Portugal), in 5275 to 7250 meters.

Bathyeliasona kirkegaardi is a deep-sea scale worm which is only known to occur in the Pacific Ocean, where it is recorded from a depth range of about 5,500–8,000 m.