Calanoidea: Families

J.M. Bradford-Grieve


Tharybidae Sars, 1902

Description. Female. Anterior head in dorsal view rounded or bluntly triangular. Rostrum with 2 filaments, or without filaments; rostral margin extends into 2 points, or 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, or separate. Posterior corners of prosome in lateral view bluntly rounded, or with 1 acute point, or divided into 2 protrusions, or triangular or obtusely pointed; dorsal view symmetrical. Genital double-somite symmetrical in dorsal view, or asymmetrical in dorsal view; gonopores close together and totally covered by single genital operculum; with pair of seminal receptacles; with pair of copulatory pores that are completely covered by genital operculum. Caudal rami symmetrical; seta VII located ventrally.

Mouthparts. Antenna 1 with 23-24 free segments; ancestral segments X and XI fused. Antenna 2 exopod with 6 free segments; 8-12 setae; basis and endopod separate. Mandible basis with 1 seta, or with 2 setae, or with 3 setae, or with 4 setae; endopod terminal segment with 7 setae, or 9 setae, or 10 setae. Maxilla 1 basal exite seta absent; exopod extends short of endopod distal border. Maxilla 2 coxal epipodite seta absent; endopod setae of sensory type; endopod with 3 worm-like setae, or with 5 worm-like setae, or with 6 worm-like setae; endopod with 2 brush-like setae, or with 3 brush-like setae, or with 5 brush-like setae, or with 6 brush-like setae. Maxilliped with normally-developed coxa, basis and endopod; coxal endite 2 with 2 setae, or with 3 setae.

Legs. Leg 1 basis outer seta present, or absent; endopod with 1 segment; exopod with 3 segments; exopod segment 1 with outer distal spine; exopod segment 3 with 3 inner setae. Leg 2 endopod with 2 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 4 inner setae. Leg 4 endopod segment 3 with 5 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, symmetrical or asymmetrical, coxae and intercoxal sclerite fused or separate, basis naked, exopod 1-segmented with terminal teeth (articulated and non-articulated) and may have inner and outer border spines, or basis and exopod apparently fused (Parundinella), surface or segments may be spinous.

Mode of life. Benthopelagic, in oceanic waters or in coastal waters.

Distribution on sea floor. 100-200 m, or 200-1000 m.

Generic composition. This family contains the genera: Parundinella Fleminger, 1956; Rythabis Schulz & Beckmann, 1995; Tharybis Sars, 1902; Undinella Sars, 1900. Other genera e.g. Pseudophaenna Sars, 1902; Neoscolecithrix Canu, 1896; Cenognatha Bradford-Grieve, 2001, Falsilandrumius Vyshkvartzeva, 2001; Grievella Ferrari & Markhaseva, 2000; Landrumius Park, 1983; Puchinia Vyshkvartzeva, 1989; and Xantharus Andronov, 1981 also key out to this family in this key but do not fit easily within its ranks (Schulz & Beckmann 1995). There is a need for further review of a number of genera and families in the Clausocalanoidea.


(Variant) Male (sexually dimorphic characters).

Description. Male. Posterior corners of prosome in lateral view bluntly rounded, or divided into 2 protrusions. Caudal rami seta VII absent.

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

Legs. Right leg 5 uniramous, or biramous; endopod separate from basis and 1-segmented, or 2-segmented; exopod elongate, 2-3-segmented, longer than, subequal to or shorter than right exopod. Left leg 5 uniramous, or biramous; endopod 1-segmented, or 2-segmented; exopod elongate, 3-segmented, longer than, subequal to or shorter than right exopod.



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