Hamaticoxa, 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 : 621

Hamaticoxa gen. nov.

Diagnosis. Body vermiform, cylindrical, consistingof cephalosomeandelongatetrunk.Trunkbilobedposteriorly due to fusion of caudal rami; vestiges of caudal setae present on apex of each lobe. Rostrum well-developed. Antennule short, broad, obscurely segmented, armedwith minute setae. Antenna 3-segmented with small terminal claw. Labrum simple. Mandible consisting of coxal gnathobase transformed to powerful, strongly curved hook and small, lobate, unsegmented palp bearing few setae. Maxillule unsegmented with several setae. Maxilla indistinctly 3-segmented with several setae. Maxilliped and legs absent.

Type species. Hamaticoxa nuda gen. et sp. nov. by original designation.

Etymology. The generic name is formed from the combination of the Latin hamat (=hooked) and cox (=the hip), referring to the hooked coxa of the mandible.

Remarks. This new genus is characterised by its unusual mandible in which the coxal gnathobase is transformedtoapowerfulhookandthepalpisrudimentary. Within the Notodelphyidae , a similarly hooked coxal gnathobase on the mandible is present only in Ademoixys gen. nov. However, these two genera cannot be confused, because in the latter the body is fusiform, with a free urosome and distinct caudal rami, the mandibular palp is biramous, and the maxillipeds and legs 1–5 are present.