Calanoidea: Families

J.M. Bradford-Grieve


Nullosetigeridae Soh, Ohtsuka, Imabayashi, Suh, 1999

Description. Female. Rostrum without filaments; rostral margin extends into 2 points. Cephalosome and pedigerous somite 1 separate; pedigerous somites 4 and 5 fused or partly fused. Posterior corners of prosome in lateral view bluntly rounded, or with 1 acute point, or triangular or obtusely pointed; dorsal view symmetrical, or asymmetrical. Genital double-somite symmetrical in dorsal view, or asymmetrical in dorsal view; gonopores not covered by genital operculum; with pair of seminal receptacles; with pair of copulatory pores on surface of somite. Caudal rami symmetrical.

Mouthparts. Antenna 1 with 24 free segments; ancestral segments X and XI separate. Antenna 2 exopod with 8 free segments; 8 setae; basis and endopod separate. Mandible basis without setae; endopod terminal segment with 6-7 setae. Maxilla 1 basal exite seta absent; exopod extends as far as endopod distal border. Maxilla 2 coxal epipodite seta absent; endopod setae normal, or claw-like. Maxilliped coxal endite 2 with 1 seta, or with 2 setae.

Legs. Leg 1 basis inner distal seta inserted directly on surface of joint; outer seta present; 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, not natatory, coxae and intercoxal sclerite fused, basis with outer border seta, exopod 3-segmented with I-0; 0-1; 0,0,I spines and setae, outer distal borders of exopod segments 2 and 3 expanded and toothed.

Mode of life. Pelagic, in oceanic waters.

Depth distribution. Mesopelagic (500-1000 m), or bathypelagic (greater than 1000 m).

Generic composition. This family contains only one genus Nullosetigera Soh, Ohtsuka, Imabayashi, Suh, 1999. This genus was previously known as Phyllopus Brady, 1883 but this name was discovered to be a preoccupied (Soh et al. 1999).


(Variant) Male (sexually dimorphic characters).

Description. Male. Posterior corners of prosome in lateral view bluntly rounded, or triangular or obtusely pointed; dorsal view symmetrical.

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 3-segmented, segments 2 and 3 more or less fused, segment 3 expanded and truncate distally. Left leg 5 biramous; endopod 1-segmented; exopod 3-segmented, segments 2 and 3 in the form of a chela.



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