Nodoscarus bretoni, 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 : 633-635

Nodoscarus bretoni gen. et sp. nov.

( Figs. 427 , 428 )

Typematerial. Holotype (intact ♀, MNHN-IU-2014- 21450 ) , paratype (intact ♀, MNHN-IU-2014-21451), and dissected paratypes (2 ♀♀, figured) from Pseudodistoma crucigaster Gail, 1972 (MNHN-IT-2008-7337 = MNHN A1/ PSE /73), Cerbère, Mediterranean coast of France, depth 19 m, G. Breton coll., 17 August 1996.

Etymology. Thenew speciesis named after G. Breton, Université de Renne, the collector of the type host.

Descriptionoffemale. Body ( Fig. 427A ) vermiform, cylindrical, unsegmented, and curved. Bodylength 6.83 mm; posterior half of body thicker (0.96 mm in diameter) than anterior half (0.71 mm in diameter). Body surface denselyornamented withcoveringoffine setules. Inlateral view, cephalic region tapering anteriorly and posterior region tapering posteriorly; cephalosome ( Fig. 427C, D ) discernible from metasome by lateral constriction. Free urosome ( Fig. 427B ) discernible from metasome by dorsal suture line, wider than long, with bilobed posterior margin; no trace of suture between metasomeand urosome on ventral side. Caudal rami absent (fully incorporated into bilobed posterior margin), but 1 caudal seta present on tip of paired posterior lobes of abdomen.

Rostrum ( Fig. 427E, F ) large, aslongas wide, tapering towards blunt apex. Antennule ( Fig. 427G ) shortand broad, strongly tapering, 115×150 μm, with 3 or 4 partial sutures along posterior side; armed with setae and ornamented with setules; number of setae not confirmed due to resemblance to setules. Antenna ( Fig. 427H ) 3-segmented, moderately slender; first and second segments (coxa and basis) unarmed; thirdsegment (endopod) about 3.5 times longer than wide (81×23 μm), as long as basis: armed with 8 small setae arranged as 3, 2, and 3, plus terminal claw slightly less than half length of endopod.

Labrum ( Fig. 428A ) setulose, shortand broad, with broad posteromedian protuberance. Mandible ( Fig. 428B ) lacking coxa; palpcomprisingouterprotuberance (exopod) bearing 4 setae, and endopod indistinctly demarcated from basis and incompletely 2-segmented, with 1 seta on mediodistal corner of first segment, and 5 setae (2 medial, 2 distal, and 1 outer) on second segment; all setae on palp weakly pinnate. Maxillule ( Fig. 428C, D ) lobate, obscurely biramous distally, and armed with 2 or 3 setae on medial margin, 4 setaeon outer ramus, and 3 setae on inner ramus (1 of 3 setae on medial margin small or may be lacking). Maxilla ( Fig. 428E ) 3-segmented and armed with 4, 1, and 3 pinnate setae on first to third segments, respectively; thirdsegment incompletely articulated from second. Maxillipeds and legs absent.

Male. Unknown.

Remarks. Species of Nodoscarus gen. nov. can be differentiated from one another by the different setation patterns of the mouthparts. The mandible and maxillule of N. bretoni gen. et sp. nov. are each armed with 10 setae, the highest number of setae found in any species of Nodoscarus gen. nov.

Figures

FIGURE 427. Nodoscarus bretoni gen. et sp. nov., female. A, habitus, right; B, posterior end of body, dorsal; C, cephalosome, dorsal; D, cephalosome, right; E, cephalosome, ventral; F, rostrum; G, antennule; H, antenna. Scale bars: A, 1 mm; B–E, 0.1 mm; F–H, 0.02 mm.

FIGURE 428. Nodoscarus bretoni gen. et sp. nov., female. A, labrum; B, mandible; C, D, maxillules; E, maxilla. Scale bars: 0.02 mm.