Haplostatus dakarensis, Kim & Boxshall, 2020

Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), Megataxa 4 (1), pp. 1-6 : 646-648

Haplostatus dakarensis sp. nov.

( Fig. 439 )

Typematerial. Holotype (intact ♀. MNHN-IU-2014- 21462 ) , paratype (intact ♀, MNUN-IU-2014-21463), and dissectedparatype (♀, figured) from Cystodytes roseolus Hartmeyer, 1912 (MNHN-IT-2008-2603 = MNHNA 3/ CYS /36), off Dakar, Senegal, Leung Tar kit coll.

Additionalmaterial. 3 ♀♀ (MNHN-IU-2018-1915) from the same host species and same locality as the type material.

Etymology. The name of the new species refers to the type locality, Dakar, Senegal..

Descriptionoffemale. Body ( Fig. 439A ) vermiform, cylindrical, slightly arched ventrally, narrowing anteriorly and posteriorly, without any metameric subdivision. Body length 4.42 mm in holotype; greatest width 1.12 mm in middle; body lengths of 2 paratypes 3.04 and 5.20 mm. Body surface smooth, without ornamentation of setules or wrinkles. Freeurosome ( Fig. 439B, C ) short, occupying 7% of total body length, obscurely 3-segmented, with additional partial suture line (or wrinkle) dorsally, anterior to first urosomite and 4 faint sclerotization bands on dorsal side ( Fig. 439C ). Last urosomite (anal somite) weakly bilobed; each lobe tipped with small, pointed, claw-like process ( Fig. 439B, C ).

Rostrum ( Fig. 439D, E ) distinct, slightly widerthan long, tapering towards rounded distal margin. Antennule ( Fig. 439F, G ) lobate, unsegmented, widerthan long, ornamented with few, minute spinules subdistally. Antenna ( Fig. 439H ) located deep inside pre-oral cavity ( Fig. 439D ); stout, 2-segmented, both segments unarmed; distal (endopodal) segment strongly tapering, fused to terminal claw, leaving only partial non-sclerotized region as vestige of articulation.

Labrum ( Fig. 439I ) broadening posteriorly, located deep inside pre-oral cavity, unornamented, with slightly concave posterior margin. Mandibles, maxillules, maxillae, maxillipeds and legs absent.

Male. Unknown.

Remarks. Haplostatus incubatrix , the type species of the genus, is associated with the compound ascidian Cystodytes dellechiajei (Della Valle, 1877) found in the Mediterranean Sea ( Illg & Dudley, 1961). Haplostatus dakarensis sp. nov. differs from thetype species as follows: (1) the body surface is smooth, without setules or wrinkles, compared to the presence of an ornamentation of fine setules over the entire body surface in H. incubatrix , as described by Illg & Dudley (1961); (2) the antennule is wider than long and carries a few spinules, compared to the antennule of H. incubatrix which is longer than wide ( Illg & Dudley, 1961); (3) the endopod and terminal claw of the antenna are fused, compared to the free terminal claw of H. incubatrix ; and (4) the mouthparts are all lacking, whereas one pair of mouthparts is retained in H. incubatrix .

Figures

FIGURE 439. Haplostatus dakarensis sp. nov., female. A, habitus, right; B, posterior end of body, left, with inset showing claw–like process on anal somite; C, posterior end of body, dorsal; D, cephalic region, right; E, cephalic region, ventral; F, antennule, dorsal; G, antennule, ventral; H, antenna; I, mandible. Scale bars: A, 1 mm; B–D, 0.1 mm; E, I, 0.05 mm; F–H, 0.02 mm.