Tribus Calyptommini W.M. Tattersall, 1909

Calyptomminae W.M. Tattersall 1909: 137.

Calyptomminae – W.M. Tattersall 1911: 59–60 (definition).

Erythropini – Illig 1930: 572 (in key, partim). — Tattersall & Tattersall 1951: 186 ( partim). — Mauchline 1980: 21 ( partim). — Tchindonova 1981: 26 ( partim).

Leptomysini – Mauchline 1980: 22 ( partim).

Calyptommini – Nouvel et al. 1999: 79. — Meland & Willassen 2007: 1093, table 1, fig. 3 (molecular phylogeny). — Wittmann et al. 2014: 337 (definition). — Meland et al. 2015: 18, table 3 (classification). — San Vicente 2017: 161.

Diagnosis

Revised from Wittmann et al. (2014) in order to receive Abyssomysis gen. nov. Eyeplate without distinct median cleft, plate mainly formed by a transverse median bridge, eyes rudimentary or absent. Antennal scale well developed, its smooth outer margin ending in a tooth; antennal gland hypertrophic. Labrum normal, symmetrical. Females with 2–3 pairs of oostegites. Pleopods uniramous, reduced to unsegmented endopods in both sexes, except that the fourth male pleopod may be sub-segmented in certain species. Uropods normal. Telson entire, lateral margins not serrated but for the most part or entirely smooth, terminal portions with spines, no setae.

Type genus

Calyptomma W.M. Tattersall, 1909.

Inventory

Three genera with a total of five species are now included: Calyptomma W.M. Tattersall, 1909, with only the nominotypical species C. puritani W.M. Tattersall, 1909, and Michthyops W.M. Tattersall, 1911, with M. parvus ( Vanhöffen, 1897), M. theeli ( Ohlin, 1901) and M. arcticus Petryashov, 1993, finally the below described Abyssomysis gen. nov. with its only species A. cornuta gen. et sp. nov.

Distribution

The species of Calyptomma and Michthyops are mostly bathybenthic, living on or close to the sea floor of the Arctic Ocean, North Atlantic and Mediterranean. Only M. theeli has been found in a wider depth range of 27–2245 m. With the below records of A. cornuta gen. et sp. nov. the geographical range of the

tribe is extended to 17° S in the SE-Atlantic, and the bathymetrical range to the abyssobenthos down to 5460 m depth. For additional distribution data see key to species below.