Marumomysis antarctica, San Vicente, 2007

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

Marumomysis antarctica San Vicente, 2007

Marumomysis antarctica San Vicente, 2007: 685–689, figs 1–4.

Marumomysis antarctica – San Vicente 2010: 47, figs 26, 36d–e (diagnosis, distribution). — Petryashov 2014a: 149–150 (biogeography). — Wittmann 2020: 33 (eye morphology, in comparison). — Mees & Meland 2024: AphiaID 431975 (accepted).

Material examined

SOUTHERN OCEAN • 1 ♀ ad. ( BL = 23.1 mm), 1 ♂ subad. (at pre-molt stage, BL = 9.7 mm), 1 imm.; Drake Passage , N of South Shetland Islands, ANDEEP-I station 114-4; 61°43.54ʹ S, 60°44.20ʹ W to 61°43.54ʹ S, 60°44.55ʹ W; depth 2914–2920 m; 18 Feb. 2002; EBS supranet .

Type locality and distribution

The type locality is in the Southern Ocean: Bellingshausen Sea, 68°59ʹ53ʺ S, 90°26ʹ58ʺ W, depth 1895 m ( San Vicente 2007). Additional records in the Bellingshausen Sea at 69– 70° S, 80– 90° W, depth 1320–1895 m ( San Vicente 2010). The present record at ANDEEP I station 114-4 is in the Drake Passage at 62° S 61° W, depth 2914–2920 m, indicating significant latitudinal, longitudinal and bathymetric extensions of the known range. The resulting total range is 62– 70° S, 61– 90° W, depth 1320–2920 m.

Remarks

Eye rudiments set apart, sickle-shaped with single, tooth-like, non-sensory disto-lateral process, organ of Bellonci present near base, no visual elements, no ocular papilla. Basal segment of antennular trunk dorsally with antennular bursa, ventrally with rounded mid-sagittal carina. Terminal segment without female lobe. Disto-median lobe with four barbed setae and six teeth, five of the latter increasing in size laterally (three such teeth in Dactylamblyops benthophilus sp. nov.: Fig. 4B ); as an unusual feature, small sixth tooth on lateral side of largest tooth in M. antarctica . Both rami of pleopod 4 with nine segments in present subadult male. In the original description, San Vicente (2007) reported nine segments in the exopod vs twelve in the endopod of adult males. In the ANDEEP material the left antennular trunk of the adult female and the frons of the subadult male are infested with settled spores of ellobiopsid parasites.

Figures

Fig. 4. Dactylamblyops benthophilus sp. nov., paratypes, adult males with BL of 20.3 mm (A–D, G: ZMH 64670), 17.0 mm (F, H: ZMH 64674) and adult female 21.8 mm (E: ZMH 64676). A. Male antennula, obliquely dorsal. B. Detail of A, showing disto-median lobe of antennular trunk. C. Antenna, dorsal view, setae of antennal scale omitted. D. Eyes and carapace expanded on slide, dorsal view. E. Labrum, ventral = aboral. F. Mandibles with right palpus, rostral view. G. Labium, caudal view; right lobe (visualized to the left) inclined with respect to the observation plane. H. Maxillula, caudal view.