Calanoidea: Families

J.M. Bradford-Grieve

Sulcanidae Nicholls, 1945

Description. Female. Rostrum without 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 with 1 acute point; dorsal view symmetrical. Genital double-somite asymmetrical in dorsal view; gonopores not covered by genital operculum; without seminal receptacles. Caudal rami symmetrical.

Mouthparts. Antenna 1 with 15-16 free segments; ancestral segments X and XI separate. Antenna 2 exopod absent; basis and endopod fused. Mandible basis without setae; endopod terminal segment with 4-5 setae. Maxilla 1 basal exite seta absent; exopod absent. Maxilla 2 coxal epipodite seta absent; endopod setae normal, or claw-like. Maxilliped with coxa large, but basis and endopod reduced; coxal endite 2 with 2 setae.

Legs. Leg 1 basis inner distal seta absent; outer seta absent; endopod with 2 segments; exopod with 3 segments; exopod segment 1 without outer distal spine; exopod segment 3 with 4 inner setae. Leg 2 endopod with 2 segments; exopod with 3 segments; exopod segment 3 with 2 outer spines. Leg 3 basis outer distal spine absent; endopod segment 3 with 7 setae. Legs 3 and 4 endopod with 3 segments; exopod with 3 segments; exopod segment 3 with 2 outer spines; exopod segment 3 with 5 inner setae. Leg 4 endopod segment 3 with 6 setae. Legs 2-4 surfaces naked; exopods with outer edge spines partially fused to their segment; terminal spine with outer border serrated. Leg 5 present; very dissimilar from legs 2-4; coxa inner border without seta; uniramous, slightly asymmetrical, not natatory; coxae and intercoxal sclerite fused; basis simple; exopod 2-segmented, segment 1 without ormament, segment 2 tapering and asymmetrically decorated on the outer border with spinules on each side.

Mode of life. Pelagic, in brackish waters.

Depth distribution. Epipelagic (0-500 m).

Generic composition. This family contains only the genus Sulcanus Nicholls, 1945.

(Variant) Male (sexually dimorphic characters).

Description. Male. Pedigerous somites 4 and 5 separate. Caudal rami asymmetrical.

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

Legs. Right leg 5 uniramous; exopod 1-segmented, tapers to end in a flattened, rounded, spoon-shaped process, exopod appears to work in opposition to long, curved spine-like process arising from inner border of basis. Left leg 5 uniramous; exopod 1-segmented, divided into 2 portions, terminal part roughly ovoid bearing single small seta terminally.

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