Monstrillopsis pontoeuxinensis sp. nov.

[ZooBank LSID # for the specific name]

Monstrillopsis pontoeuxinensis Suárez-Morales & Üstün, 2018: 553–555, figs 4, 5 (unavailable; source paper deemed unpub-

lished).

Type material. Holotype adult male deposited in collection of Zooplankton held at El Colegio de la Frontera Sur (ECO- SUR), in Chetumal, Mexico (ECO-CHZ-10337), collected from plankton on 6 June 2016 at station B, Hamsilos Bay, Sinop, Turkish coast of the Black Sea ( 35°02’36”E, 42°03’36”N); specimen partially dissected with selected appendages mounted on slide in glycerine, sealed with Entellan®.

Diagnosis. (Male) Body length excluding antennules and caudal rami 0.561 mm (48% cephalothorax, 52% urosome). Oral papilla at 31% of cephalothorax length. “Forehead” with anterior notch and few transverse striations. Antennules 1.2 times as long as cephalothorax, with distinct rounded inner proximal expansion of fifth segment. Among antennular setae, elements 1, 2v 1-3, and 3 long and setiform, element 4v1 longest among neighboring elements, elements B–D unbranched; apical process of fifth segment separated as distinct spiniform element 2. On legs 1–4, intercoxal sclerite spinulose, outer apical exopodal seta smooth externally, sparsely setose internally. Type II genital complex present, with two pairs of small, rounded processes medial to bases of lappets. Anal and preanal somites incompletely separated. Four setae on each caudal ramus subequally long.

Etymology. An adjective combining the ancient Greek name of the Black Sea, Póntos Eúxeinos, with the Latin locational suffix - ensis (feminine to match the gender of the genus).

Remarks. A full description and taxonomic illustrations of M. pontoeuxinensis, including comparisons to known congeners, was provided by Suárez-Morales & Üstün (2018).