Calanoidea: Families

J.M. Bradford-Grieve


Pseudodiaptomidae Sars, 1902

Description. Female. Rostrum with 2 filaments; rostral margin extends into 1 blunt protrusion, or not extended. Cephalosome and pedigerous somite 1 fused or partly fused, or separate; 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 2 free somites, or with 3 free somites, or with 4 free somites. Genital double-somite symmetrical in dorsal view, or asymmetrical in dorsal view; gonopores not covered by genital operculum. Caudal rami symmetrical, or asymmetrical.

Mouthparts. Antenna 1 with 21-24 free segments; ancestral segments X and XI partly fused. Antenna 2 exopod with 4 free segments; 12 setae; basis and endopod separate. Mandible basis with 4 setae; endopod terminal segment with 8-9 setae. Maxilla 1 basal exite seta present; exopod extends short of endopod distal border. Maxilla 2 coxal epipodite seta absent. Maxilliped coxal endite 2 with 3 setae.

Legs. Leg 1 basis inner distal seta absent; outer seta absent; endopod with 3 segments; exopod with 3 segments; exopod segment 1 with outer distal spine; exopod segment 3 with 3 inner setae. Leg 2 endopod with 3 segments; exopod with 3 segments; exopod segment 3 with 2 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 2 outer spines; exopod segment 3 with 5 inner setae. Leg 4 endopod segment 3 with 7-8 setae. Legs 2-4 surfaces weakly spinulose, or naked; terminal spine with outer border serrated. Leg 5 present; very dissimilar from legs 2-4; coxa inner border without seta; uniramous or biramous (Archidiaptomus), not natatory, may be slightly asymmetrical; coxa separate, intercoxal sclerite not obvious; basis usually with posterolateral seta; exopod 3-segmented (terminal 2 segments fused in Archidiaptomus), segment 1 elongate with outer distal spine, segment 2 with outer distal spine and strong inner spine-like extension, segment 3 spine-like and may have inner accessory basal spine.

Mode of life. Pelagic or benthopelagic, in coastal waters or in brackish waters or in freshwaters.

Depth distribution. Epipelagic (0-500 m).

Distribution on sea floor. Less than 100 m.

Generic composition. This family contains three genera Archidiaptomus Madhupratap & Haridas, 1978 (brackish water species); Calanipedia Kritchagin, 1873 (freshwater and occasionally brackish water species); Pseudodiaptomus Herrick, 1884 (brackish to saline species).


(Variant) Male (sexually dimorphic characters).

Description. Male. Pedigerous somites 4 and 5 fused or partly fused, or separate. Caudal rami symmetrical.

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

Legs. Right leg 5 uniramous, or biramous; endopod with no free segments, or separate from basis and 1-segmented; exopod elongate, 3-segmented, segments 1 and 2 each with strong outer distal spine, segment 3 extended into curved spine. Left leg 5 uniramous, or biramous; endopod with no free segments, or 1-segmented; exopod shorter than left exopod, 2-segmented, segment 1 with strong outer distal spine, segment 2 with outer proximal spine and variously decorated with spines and / or spinules.



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