Acuticoxa, Huys, Rony & Kihara, Terue Cristina, 2010

Huys, Rony & Kihara, Terue Cristina, 2010, Systematics and phylogeny of Cristacoxidae (Copepoda, Harpacticoida): a review, Zootaxa 2568, pp. 1-38 : 21-22

Genus Acuticoxa gen. nov.

Diagnosis. Nannopodidae . Body cylindrical; slightly depressed dorsoventrally; somites with finely incised hyaline frills and dense setular surface ornamentation; genital double-somite Ƥ completely fused. Rostrum prominent, triangular. Anal operculum moderately developed, spinulose. Caudal ramus long and rectangular; with 7 setae; seta V longest, typically composed of swollen proximal and setular distal part.

Antennule without spinous processes; 4-segmented in female; segment I elongate, segments III–IV oriented posteriorly and with aesthetasc. Antenna with abexopodal seta on allobasis; exopod absent or represented by minute unisetose segment; endopod with 6 distal (3 geniculate and 3 simple) and 2 medial elements. Mandible biramous with unisetose exopod fused to basis and 1-segmented trisetose endopod; basis with 2 setae. Maxillule with 2 elements on coxal endite; basal endites represented by 2 and 3 setae, respectively; endopod incorporated into basis and represented by 2 setae; exopod absent. Maxillary syncoxa with 2 endites bearing 2 and 3 elements, respectively; allobasis with claw and 1 accompanying seta; endopod represented by 2 setae. Maxillipedal syncoxa and basis unarmed; endopod 1-segmented with long geniculate claw and typically 1 accompanying seta.

P1 with strong unguiform outer spinous process on coxa; basis with inner and outer seta; exopod 2- segmented, exp-1 with or without outer seta, exp-2 with 5 setae; endopod prehensile, enp-1 without inner seta, enp-2 with 1 claw and 1 basally reinforced seta. P2–P4 with outer spinous projection on coxa; P2–P3 exopods 1- ( A. ubatubaensis ) or 2-segmented ( A. biarticulata ); P4 exopod 1-segmented; P2–P4 endopods 1-segmented with single apical element. Spine and setal formula as follows:

P5 exopod and baseoendopod fused in Ƥ, forming single plate with 8 setae/spines; intercoxal sclerite discernible. Genital field Ƥ with large median copulatory pore; P6 represented by 2 short setae. Type species: Acuticoxa ubatubaensis gen. et sp. nov.

Other species: Laophontisochra sp. sensu George (2002) [= Acuticoxa biarticulata sp. nov.]

Etymology. The generic name is derived from the Latin adjective acutus, meaning pointed, sharp, and the Latin noun coxa, meaning hip, and refers to the pointed projection found on the coxae of at least legs 2–4. Gender feminine.