Mysidetes sp.

Wittmann, Karl J., 2024, The Mysidae (Crustacea, Mysida) of the ANDEEP I-III expeditions to the Antarctic deep sea with the description of twelve new species, establishment of four new genera and with world-wide keys to the species of Erythropinae and Mysidellinae, European Journal of Taxonomy 940, pp. 1-180 : 121-122

Mysidetes sp. M

nec Mysidetes sp. – Wittmann et al. 1993:32. — Wittmann 1995: fig. 1c.

Material examined

SOUTHERN OCEAN • 1 imm. ( BL = 8.7 mm); South Sandwich Trench , SE of Montagu Island, ANDEEP-II station 143-1; 58°44.69ʹ S, 25°10.27ʹ W to 58°44.49ʹ S, 25°10.47ʹ W; depth 773.9– 755.6 m; 25 Mar. 2002; EBS supranet • 1 ♀ subad. ( BL = 14.1 mm); NW Weddell Sea, ANDEEP-II station 133-3; 65°20.15ʹ S, 54°14.35ʹ W to 65°20.06ʹ S, 54°14.51ʹ W; depth 1122– 1119 m; 7 Mar. 2002; EBS epinet • 2 juv., SE Weddell Sea, ANDEEP-III station 074-6; 71°18.35ʹ S, 13°57.71ʹ W to 71°18.28ʹ S, 13°57.31ʹ W; depth 1030–1040 m; 20 Feb. 2005; EBS epinet • 1 imm. (BL = 5.3 mm); eastern Weddell Slope , Kapp Norvegia , ANDEEP-III station 078-10; 71°09.39ʹ S, 13°59.30ʹ W to 71°09.36ʹ S, 13°58.81ʹ W; depth 2156– 2147 m; 21 Feb. 2005; EBS epinet • 1 ♀ subad. (BL = 16.4 mm), 6 juv. (BL = 4.1–5.9 mm); Powell Basin , SW continental slope of South Orkney Islands, ANDEEP-III station 150-6; 61°48.70ʹ S, 47°28.04ʹ W to 61°48.57ʹ S, 47°28.19ʹ W; depth 1996– 1993 m; 20 Mar. 2005; EBS epinet • 1 ♀ subad. ( BL = 16.1 mm); same collection data as for preceding except for occurrence in supranet • 1 ♂ ad. ( BL = 20.5 mm), 1 imm. ( BL = 9.6 mm); Bellingshausen Sea , NW of Anvers Island , ANDEEP-III station 153-7; 63°19.31ʹ S, 64°36.94ʹ W to 63°19.15ʹ S, 64°37.18ʹ W; depth 2092–2118 m; 29 Mar. 2005; EBS supranet .

Distribution

Widely distributed in the areas covered by the ANDEEP II–III expeditions: SE Weddell Sea, eastern Weddell Slope, NW Weddell Sea, Powell Basin, Bellingshausen Sea, South Sandwich Trench; total ranges 59– 71° S, 14– 65° W, depth 774–2147 m. The lower depth range significantly exceeds the maximum depth of 1105 m previously known for species of Mysidetes at a worldwide scale ( Wittmann & Chevaldonné 2021).

Remarks

The ANDEEP specimens closely approach the first description of Mysidetes macrops O.S. Tattersall, 1955 , and the respective features given in the worldwide key to Mysidetes species by Wittmann & Chevaldonné (2021). However, the ANDEEP specimens differ by larger body size, antennal scale extending longer beyond antennular trunk, rostrum slightly covering base of eyestalks, and tip of triangular rostrum narrowly rounded rather than acute. This material will be treated in greater detail in a forthcoming publication on Mysidetes materials from other Antarctic expeditions.