Cepolacanthus, Maran, Balu Alagar Venmathi, Moon, Seong Yong, Adday, Thamir Katea & Tang, Danny, 2016

Maran, Balu Alagar Venmathi, Moon, Seong Yong, Adday, Thamir Katea & Tang, Danny, 2016, Cepolacanthus kimi, a new genus and species of copepod (Cyclopoida: Taeniacanthidae) parasitic on Bandfish Acanthocepola abbreviata (Valenciennes, 1835) (Actinopterygii: Cepolidae) caught off the Iraqi coast, Zootaxa 4174 (1), pp. 249-258 : 251

Cepolacanthus gen. nov.

Diagnosis. Adult female. Body elongated. Prosome composed of cephalothorax (cephalosome fused with first pediger) and three free pedigerous somites. Urosome composed of fifth pedigerous somite, genital somite, and three free abdominal somites. Caudal ramus bearing seven setae. Rostrum well developed. Antennule 6-segmented, with armature formula 5, 15, 8, 4, 2 + 1 aesthetasc, 7 + 1 aesthetasc. Postantennal process present. Antenna 3- segmented, composed of coxobasis and two endopodal segments; distal endopodal segment bearing two pectinate processes, three claws and five setae. Labrum broad, ornamented. Mandible 1-segmented, with accessory seta and two terminal blades. Paragnath digitiform, ornamented. Maxillule lobate, armed with five setae. Maxilla 2- segmented, composed of syncoxa and basis; latter tapering into serrated process and bearing two unequal, separated elements. Maxilliped 3-segmented, composed of syncoxa, basis and long terminal claw (endopod). Legs 1–4 biramous. Leg 1 lamelliform, consisting of coxa, basis and 2-segmented rami. Legs 2–4 each with 3- segmented exopod and 2-segmented endopod; third exopodal segment of leg 4 with large distolateral protuberance. Leg 5 uniramous, 2-segmented, composed of protopod and 1-segmented exopod; exopod bearing one seta and three spines. Leg 6 vestigial, bearing three setae in egg sac attachment area.

Adult male. Unknown.

Type and only species. Cepolacanthus kimi sp. nov.

Etymology. The generic name is an amalgamation of cepola (= suffix of the host genus Acanthocepola ) and the Latin acanthus (= spine), a common suffix used in the formation of generic names in the Taeniacanthidae .

Remarks. Cepolacanthus gen. nov. is assigned to the Taeniacanthidae because it possesses a postantennal process, two pectinate processes plus setae and clawlike spines on the antennal endopod, at least two spinulated blades on the mandible, a spinulated terminal process on the maxilla, and a lamelliform leg 1, with an outwardlydirected endopod bearing setae along the inner margin ( Dojiri & Cressey 1987; Huys et al. 2012).

The taeniacanthid maxilla is 2-segmented and primitively bears a maximum of four elements on the distal segment. In the great majority of taeniacanthids, the distal segment of the maxilla bears only one seta and two spinulated spines, one of which is invariably fused to the terminal segment, forming what is known as a terminal process ( Dojiri & Cressey 1987). More importantly, the seta is usually positioned on the same transverse plane as the free spinulated spine ( Dojiri & Cressey 1987: Figs. 59H, 128D, 146G). In Cepolacanthus gen. nov., however, the relative positions of the two free maxillary elements are unique in that the seta is displaced more proximally on the terminal process than the spinulated spine.

The vast majority of taeniacanthids possess a 3-segmented endopod on legs 2–4. By contrast, Cepolacanthus gen. nov., Taeniacanthus mcgroutheri Tang, Uyeno & Nagasawa, 2011a , Saging cebuana Uyeno, Tang & Nagasawa, 2013 and members of Umazuracola Ho, Ohtsuka & Nakadachi, 2006 all have a 2-segmented endopod on legs 2–4. This derived character state stems from the failure of the middle and terminal segments, rather than the proximal and middle segments, to separate. Cepolacanthus gen. nov. differs markedly from T. mcgroutheri , S. cebuana and Umazuracola spp. in having: 1) a relatively smaller rostrum which bears sclerotized structures on the ventral surface; 2) plumose (vs. naked) setae on antennulary segments 1–4; 3) an accessory seta (vs. none) on the mandible; 4) eight (vs. six) elements on the terminal exopodal segment of legs 2–3; 5) seven (vs. six) elements on the terminal exopodal segment of leg 4; 6) spinulated (vs. setiform) spines on the exopod of leg 4; and 7) three spines and one seta (vs. four setae) on the free exopodal segment of leg 5. Cepolacanthus gen. nov. differs further from T. mcgroutheri by having a considerably longer body, a much longer maxillipedal claw and two (vs. one) armature elements on the terminal process of the maxilla, and from S. cebuana and Umazuracola spp. by having a maxillipedal claw (vs. absent), a well-developed (vs. vestigial) leg 1 and spinulated (vs. coarsely serrated) spines on both rami of legs 2–3 and on the endopod of leg 4.