Calanoidea: Families

J.M. Bradford-Grieve

Eucalanidae Giesbrecht, 1892

Description. Female. Rostrum with 2 filaments; rostral margin not extended. Cephalosome and pedigerous somite 1 fused or partly fused; pedigerous somites 4 and 5 fused or partly fused. Posterior corners of prosome in lateral view bluntly rounded, or with 1 acute point; dorsal view symmetrical. Urosome with 3 free somites, or with 4 free somites. Genital double-somite symmetrical in dorsal view; with pair of seminal receptacles. Caudal rami symmetrical; with both fused or partly fused to anal somite.

Mouthparts. Antenna 1 with 23 free segments; ancestral segments X and XI fused. Antenna 2 exopod with 7 free segments; 12 setae; basis and endopod separate. Mandible basis with 3 setae, or with 4 setae; endopod terminal segment with 3 setae, or 9 setae. Maxilla 1 basal exite seta present; exopod extends short of endopod distal border. Maxilla 2 coxal epipodite seta present. Maxilliped coxal endite 2 with 3 setae.

Legs. Leg 1 basis outer seta absent; endopod with 2 segments; exopod with 2 segments, or with 3 segments; exopod segment 1 with outer distal spine, or without outer distal spine. 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 5 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 5 setae. Legs 2-4 surfaces naked; exopods with outer edge spines articulated with their segment, or partially fused to their segment; terminal spine with outer border smooth. Leg 5 present, or absent; very dissimilar from legs 2-4; coxa inner border without seta; if present uniramous, coxa and intercoxal sclerite separate, basis with inner distal seta, exopod 1-segmented with 1 terminal and 1 inner border setae or 1 outer distal tooth and 1 inner border seta.

Mode of life. Pelagic, in oceanic waters.

Depth distribution. Epipelagic (0-500 m).

Generic composition. This family contains four genera: Eucalanus Dana, 1852; Pareucalanus Geletin, 1976; Rhincalanus Dana, 1852; Subeucalanus Geletin, 1976.

(Variant) Male (sexually dimorphic characters).

Description. Male. Posterior corners of prosome in dorsal view symmetrical, or asymmetrical. Caudal rami asymmetrical.

Mouthparts. Mouthparts well-developed. Antenna 1 similar, neither geniculate. Maxilliped endopod segments 5 and 6 with outer setae enlarged.

Legs. Right leg 5 absent, or uniramous; exopod absent or 2-3-segmented, subequal to right leg or much shorter, usually terminating in spine. Left leg 5 uniramous, or biramous; endopod 2-segmented; exopod ususally elongate, 2-3-segmented terminated in spine.

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