Nodoscarus 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 : 642

Nodoscarus dakarensis gen. et sp. nov.

( Fig. 435 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21458 ) anddissectedparatype (♀, figured) from Cystodytes roseolus Hartmeyer, 1912 (MNHN-IT-2008- 2602 = MNHNA 3/ CYS /4), Dakar, Senegal, dredge, IFAN coll., 21 January 1941.

Etymology. The new species is named after the type locality, Dakar, Senegal.

Descriptionoffemale. Body ( Fig. 435A ) vermiform, cylindrical, slightly arched ventrally, unsegmented, surface densely covered with fine setules. Body length 1.30 mm; body width 0.25 mm across widest mid-region. Anterior and posterior extremities of body blunt; posterior margin ( Fig. 435B ) with weak median (anal) incision. No caudal rami or caudal setae present.

Rostrum ( Fig. 435 C-E) small, lobate, widerthan long, setulose. Antennule ( Fig. 435D, F ) also lobate, unsegmented, wider than long with strongly tapering distal part; denselysetulose andsetae apparently absent.Antenna ( Fig. 435G ) 3-segmented, stout; coxaandbasisunarmed; unsegmented endopod and terminal claw fused with each other, tapering to pointed tip, 2.5 times longer than wide (45×18 μm); armed with 5 small setae subdistally.

Labrum small, not covering mouthparts ( Fig. 435D ). Mandible ( Fig. 435H ) unsegmented, but with constriction near middle; armed with 5 naked setae (2 subdistal and 3 distal). Maxillule ( Fig. 435I ) as lobe bearing 7 subequal, naked setae (3 on medial margin). Maxilla ( Fig. 435J ) incompletely 2-segmented, armedwith 6 naked setae, 1 on first segment and 5 (2 subdistal and 3 distal) on second; 1 distal seta markedly enlarged. Maxillipeds and legs absent.

Male. Unknown.

Remarks. Nodoscarus dakarensis gen. et sp. nov. can be distinguished from its congeners by the characteristic form of its antenna and the setation patterns of the mouthparts. The endopod and terminal claw of the antenna are completely fused, a rare feature within the Notodelphyidae . The mandible, maxillule and maxilla are armed with 5, 7, and 6 setae, respectively, each of these numbers is unique and not shared with any currently known species of Nodoscarus gen. nov.

Figures

FIGURE 435. Nodoscarus dakarensis gen. et sp. nov., female. A, habitus, right; B, posterior end of body, ventral; C, cephalic region, right; D, cephalic region, ventral; E, rostrum; F, antennule; G, antenna; H, mandible; I, maxillule; J, maxilla. Scale bars: A, 0.2 mm; B, C, 0.05 mm; D–G, 0.02 mm; H–J, 0.01 mm.