Amphiura carchara H. L. Clark 1911

Amphiura carchara H.L. Clark, 1911

Fig. 14G‒L

Amphiura carchara H.L. Clark, 1911: 142‒143, fig. 55.— Martynov 2010: figs. 15m, 31f.

Pandelia carchara. Fell 1962: 10.— Kyte 1969a: 1737.

Material examined. 31 individuals at three stations. TALUD XVIB, Sta. 22, 1 ind. (ICML-EMU-11149-A) and 4 ind. (ICML-EMU-11149-B); Sta. 26, 1 ind. (ICML-EMU-11149-C); Sta. 27, 10 ind. (ICML-EMU-11150) and 15 ind. (ICML-EMU-11667).

Comparative material. Holotype: USNM 25594. Paratypes, 158 ind.: MCZ OPH-3140, MCZ OPH-3141, MCZ OPH-3370, USNM 25993, USNM 26053, USNM 26114, USNM 26115, USNM 26213, USNM 26615, USNM 27017, USNM 27018, USNM 27054, USNM 32377, USNM 33639 (Supplementary file 2).

Description (ICML-EMU-11667). DD = 7 mm. Disc rounded. Dorsal disc covered by imbricated scales. Primary plates oval, separated from each other by scales. RS triangular with rounded edges, in contact only distally, the rest separated by scales (Fig. 14G). Ventral interradii covered by integument, distally with a fold of scales (Fig. 14H). OSh broader than long, bell-shaped with rounded edges, a distal lobe. Madreporite not evident. AdSh triangular, wider distally, meeting in front of OSh or separated. Jaws bearing three oral papillae at each side; AdShSp elongated, pointed; BSc elongated, pointed; IPa quadrangular with rounded edges, strong. vT elongated with straight edge (Fig. 14I). Arms slender. DAP broader than long, fan-shaped with rounded edges, contiguous (Fig. 14J). VAP longer than broad, pentagonal, slightly separated from each other. LAP with three ArSp, small (approximately 1.5 arm segment in length), pointed, middle ArSp stronger than rest. Tentacle pores with one oval TSc (Fig. 14K). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) (Fig. 14G‒L).

Habitat and distribution. Bering Sea, Gulf of Alaska, Washington, USA, and northwestern Mexico (H.L. Clark 1911; Granja-Fernández et al. 2015); 568‒ 3,611 m depth, sandy and muddy substrates (H.L. Clark 1911; Maluf 1988). The material examined was collected in northwestern Baja California; 982‒ 1,560 m depth.

Remarks. Examination of the types and the material available herein showed that the morphology in Amphiura carchara is very constant. The only variation observed during this study was the presence of round and separated primary plates in specimens with a DD <5 mm vs. no easily distinguishable primary plates in individuals with a DD> 6 mm.