Calanoidea: Families

J.M. Bradford-Grieve

Hyperbionycidae Ohtsuka, Roe, Boxshall, 1993

Description. Female. Rostrum with 2 filaments; rostral margin not extended. Cephalosome and pedigerous somite 1 separate; pedigerous somites 4 and 5 fused or partly fused. Posterior corners of prosome in lateral view bluntly rounded; dorsal view symmetrical. Genital double-somite asymmetrical in dorsal view; gonopores not covered by genital operculum; with one seminal receptacle; with single copulatory pore on surface of somite. Caudal rami asymmetrical; separate from anal somite.

Mouthparts. Antenna 1 with 25 free segments; ancestral segments X and XI separate. Antenna 2 exopod with 9 free segments; 8 setae; basis and endopod separate. Mandible basis without setae, or with 1 seta; endopod terminal segment with 2 setae, or 3 setae, or 5-8 setae. Maxilla 1 basal exite seta absent; exopod extends as far as endopod distal border. Maxilla 2 coxal epipodite seta absent. Maxilliped coxal endite 2 with 1 seta.

Legs. Leg 1 basis outer seta absent; endopod with 3 segments; exopod with 3 segments; exopod segment 1 with outer distal spine; exopod segment 3 with 4 inner setae. Leg 2 endopod with 3 segments; exopod with 3 segments; exopod segment 3 with 3 outer spines. Leg 3 basis outer distal spine absent; endopod segment 3 with 8 setae. Legs 3 and 4 endopod with 3 segments; exopod with 3 segments; exopod segment 3 with 3 outer spines; exopod segment 3 with 5 inner setae. Leg 4 endopod segment 3 with 7 setae. Legs 2-4 surfaces naked; terminal spine with outer border serrated. Leg 5 present; very dissimilar from legs 2-4; coxa inner border without seta; uniramous, coxae and intercoxal sclerite fused, basis with outer seta, exopod 1-segmented, oval shaped, with 2 outer border spines and 3 inner border setae.

Mode of life. Benthopelagic, in oceanic waters.

Distribution on sea floor. Greater than 1000 m.

Generic composition. This family has only one genus Hyperbionyx Ohtsuka, Roe, Boxshall, 1993.

(Variant) Male (sexually dimorphic characters).

Description. Male.

Mouthparts. Mouthparts well-developed. Antenna 1 geniculate on left. Maxilliped endopod segments 5 and 6 with outer setae normal.

Legs. Right leg 5 uniramous; exopod 2-segmented, segments 2 and 3 almost completely fused, segment 1 with short outer distal spine, segment 2 lamellar forming pocket-like structure. Left leg 5 uniramous; exopod 3-segmented, segment with outer distal spine, segment 2 elongate with strong spine at midlength, segment 3 tapering distally, curved inwards.

Cite this publication as: 'Bradford-Grieve, J.M. (2002 onwards). Calanoida: families. Version 1: 2 October 2002.'.