Gymnobela angulosa Sysoev, 1988 (PSH G3)

(Figures 4H–K, 6D)

Gymnobela angulosa Sysoev, 1988 – Sysoev 1988, p. 965 –967; pl. 2, figs. 1–2; pl. 3, fig. 1

Holotype (Figure 4H). Tasman Sea (− 39.950°S, 165.130°E), Station no. 3156, 5525 m, RV Vityaz, ZMMU Lc-22363.

Material examined

Other material: Australia, Tasmania /Victoria, Bass Strait (− 39.552°S, 149.553°E), IN2017_ V03 _030, 4197– 4133 m, 1 wet (AMS C.571648), 1 wet (AMS C.571649); Africa, Guinea, Guinea Basin, M 63–2, Station 94–8 EBS (0.630°N, −6.430- 6° 25’ 48”W), M 63–2 (94–8), 5151- m, 1 wet (ZSM mol_20070770) .

Distribution

N Pacific Ocean (off Japanese Archipelago); Tasman Sea (Bass Strait), Central Atlantic (off western Africa).

Remarks

At the time of writing, the holotype of this species could not be located by staff of the Zoological Museum of Moscow University (ZMMU), and all observations were conducted on the only available photograph of its shell (Figure 4H) . The shell of G. angulosa (Figures 4H–K) is similar to that of G. mitrodeta (Figure 8G), differing by its taller spire and more cylindrical whorl profile.

As no description of the anatomy is available for this species [except for a figure of the radula of the holotype (Sysoev 1988, pl. 3, fig. 1)], further anatomical details (based on AMS C.571648) are given below. Animal pale blue. Cephalic tentacles short, blunt; eyes very small. Venom apparatus: proboscis long, coiled; venom gland very long, convoluted; muscular bulb moderately large, elongate-ovate, pearlescent. Radula of hypodermic teeth, straight, tightly rolled; approximately 150 µm in length; adapical opening long; ventral side forming blade approximately 1/5 of length of tooth; base wide, angular, with lateral process; texture rugose; basal opening large, subcircular, unrestricted.