Pseudoscalibregma bransfieldium Hartman 1967

Pseudoscalibregma bransfieldium (Hartman, 1967)

Figure 6 F‒G

Eusclerocheilus bransfieldia Hartman, 1967: 130 ‒131, pl. 39

Hyboscolex bransfieldia: Kudenov & Blake, 1978: 440.

Pseudoscalibregma bransfieldia: Hartman, 1978: 180 ‒181, fig. 28

Pseudoscalibregma bransfieldium: Blake, 1981: 1143 ‒1145, fig. 6; Hartmann-Schröder & Rosenfeldt, 1991: 75.

Material examined. East Antarctic Peninsula, RVIB Nathaniel B. Palmer Cruise 2000-03, Collector, J.A. Blake. —Larsen-A Ice Shelf Area, transect along border with Larsen B, Sta. NBP- 10, 332 m, 1 specimen (LACM- AHF Poly 7010).

Additions to description. Single specimen complete, 10 mm long, 3 mm wide with 22 setigers; the body more maggot-shaped than arenicoliform. In alcohol, color light tan with no body pigment.

Prostomium bears two long frontal horns projecting anterolateral; dorsal surface of prostomium somewhat domed or elevated, clearly visible; eyes absent; nuchal organs not apparent. Peristomium a single dorsal ring surrounding the prostomium dorsally; ventrally forming upper and lower lips of mouth with upper lip relatively smooth and lower lip with three weakly developed lobes. A weakly developed ventral groove apparent along body from setiger 4; initially, groove formed by a single large segmental annulus that at the mid-point produces a notch between segments; in last 5‒6 segments, a distinct furrow develops at segmental mid-point. The pygidium damaged, but bears five anal cirri.

Anterior parapodia weakly developed with low noto- and neuropodia; posteriorly podial lobes elongate, apically pointed, bearing distinctive dorsal and ventral cirri (Fig. 6 G), both of which are bulbous extensions of the podial lobes; internal glands absent from cirri and elsewhere on body. Interramal papillae weakly developed.

Setae consist of numerous capillaries arranged in 2‒3 rows throughout; lyrate setae from setiger 2; setiger 1 bears an anterior row of short, thin, spinous setae (Fig. 6 F) anterior to capillaries, the homologues of lyrate setae now known to occur on numerous species of Scalibregmatidae.

Remarks. Pseudoscalibregma bransfieldium differs from other scalibregmatids by the distinctive dorsal and ventral inflated extensions of the podial lobes. The short anterior spinous setae of setiger 1 are newly reported.

Distribution. Widespread in Antarctic seas 332‒ 916 m.