Enteropsis tromsoensis, Kim & Boxshall, 2021

Kim, Il-Hoi & Boxshall, Geoff A., 2021, Copepods (Cyclopoida) associated with ascidian hosts: Ascidicolidae, Buproridae, Botryllophilidae, and Enteropsidae, with descriptions of 84 new species, Zootaxa 1, pp. 1-286 : 275-277

Enteropsis tromsoensis sp. nov.

( Figs. 182 )

Type material. Holotype ♀ (MNHN-IU-2014-21586) and paratype ♀ (dissected, MNHN-IU-2014-21499) from mçlycarpa fẚbrçsa (Stimpson, 1852) (MNHN-IT-2008-6485 = MNHN S1 / POL.B/54); off Tromsø , Norway, Norbi Cruise, RV “Jean Charcot”, Stn CP 11 (69°52’N, 17°08’E), depth 250-300 m, Bouchet & Warén coll., 01 July 1975.

Additional non-type material. 2 ♀♀ (MNHN-IU-2014-21587, intact) in mçlycarpa pçrculus Monniot C. & Monniot F., 1979; collected at type locality on same date.

Etymology. The name of the new species is based on its type locality, Tromsø.

Description of female. Body ( Fig. 182A ) eruciform, incompletely 7-segmented, consisting of cephalosome, first to fourth pedigerous somites, genital complex, and 1-segmented abdomen. Body length 2.23 mm; maximum with 682 μm (across second pedigerous somite). Cephalosome 360×490 μm, distinctly defined from first pedigerous somite; posterior part of body from second pedigerous somite narrowing posteriorly. Genital apertures positioned laterally on genital complex. Abdomen 250×290 μm, gradually narrowing posteriorly; anus opening dorsally; anal prominence and anal operculum absent ( Fig. 182B ). Caudal rami ( Fig. 182B ) tapering, about 2.9 times longer than wide (208×71 μm), with straight, sclerotized lateral margin and oblique medial margin, and tipped with 1 small spine (55 μm long).

Rostrum absent. Antennule ( Fig. 182C ) broad, indistinctly 2-segmented, 70×50 μm; proximal segment un- armed; distal segment with 6 or 7 setae (3 setule-like and 2 with swollen articulated base); 1 small distal seta (indicated by arrowhead) present or absent. Antenna ( Fig. 182D ) consisting of proximal segment and large distal claw; proximal segment 45 μm long, with 1 small cusp subdistally; distal claw (or claw-like distal segment) 50 μm long, slightly curved, unarmed.

Labrum ( Fig. 182E ) armed with 5 broad, spinulose, setiform processes along posterior margin, middle 3 processes about 33 μm in length and about 1.5 times longer than lateral 2. Mandible absent. Maxillule ( Fig. 182F ) bilobed distally, with 5 elements on inner lobe and 3 elements on outer lobe, all elements ornamented with minute spinules; 5 elements of inner lobe consisting of 2 shorter processes and 3 slender setiform elements; elements on outer lobe all broad, blunt processes. Maxilla ( Fig. 182G ) massive, 2-segmented; broad proximal segment bearing 1 sclerotized tubercle on protruding medial margin; distal segment terminating in strong claw, with 1 small seta proximally. Maxilliped absent.

Leg 1 ( Fig. 182H ) 2-segmented; proximal segment unarmed, with scattered minute spinules on anterior surface; distal segment bearing 1 claw (representing exopod) and 1 shorter, tapering, corrugated process (endopod). Legs 2-4 same as leg 1. Leg 5 absent. Leg 6 not visible.

Male. Unknown.

Remarks. bnterçpsẚs trçmsçensẚs sp. nov. can be clearly defined by the characteristic armature of the labrum and maxillule. Its labrum is armed with 5 setiform processes along the free posterior margin. Although Illg & Dudley (1980) recorded the presence of 5 or 6 “setae” on the labrum of b. capẚtulata, these elements were described as small, naked, and arranged along the anterior margin of the labrum. No other congeners are recorded as having 5 setae or processes on the labrum. The maxillule of b. trçmsçensẚs sp. nov. is armed with 3 processes on the inner lobe and 5 processes on the outer lobe. The numbers of processes are extraordinary because they exceed the previously known maximum numbers, which are 2 on the inner lobe and 3 on the outer lobe (reported in five other species).

Figures

FIG. 182. bnterçpsẚs trçmsçensẚs sp. nov., female. A, habitus, dorsal; B, caudal rami, dorsal; C, antennule; D, antenna; E, labrum; F, maxillule; G, maxilla; H, leg 1. Scale bars: A, 0.5 mm; B, 0.1 mm; C-F, 0.02 mm; G, H, 0.05 mm.