Tumidochelia Knight, Larsen

Larsen, Kim & Shimomura, Michitaka, 2007, Tanaidacea (Crustacea: Peracarida) from Japan. II. Tanaidomorpha from the East China Sea, the West Pacific Ocean and the Nansei Islands, Zootaxa 1464, pp. 1-43 : 4

Genus Tumidochelia Knight, Larsen & Heard, 2003

Diagnosis. Female (modified from Knight et al. 2003). Body elongate. Antennule article 1 shorter than rest of antennule, article 2 almost as long as article 1. Antenna with five or six articles, article 3 with or without fusion line. Mandible molar pointed but not quite as much as in Leptognathia , with small apical spines. Cheliped with inflated “shield-like” expansion of the inner distal side of the carpus. Pereopod 1 carpus shorter than merus Pereopods 1–3, propodus longer than dactylus and unguis combined. Pereopods 4–6, propodus longer, or as long as dactylus and unguis combined. Pleopods small but present. Uropod bearing spiniform distal process on inner margin of basal article; endopod and exopod each with 2 articles.

Male. Listed as ‘unknown’ by Knight et al. (2003) but one male is reported by Hansen (1913:84, pl.VIII, 4f–i) belonging to L. uncinata (transferred to Tumidochelia below). This male is of the ‘swimming male’ type with no functional mouthparts, reduced pereon, and multiarticulated antennule with multiple aesthetacs, but differing from the leptognathid male by a biarticulated uropodal exopod. It is not certain that his male belongs to Tumidochelia as other species (leptognathids) were found in the same sample.

Type species. Tumidochelia randyi Knight, Larsen & Heard, 2003 by monotypy.

Gender. Feminine.

Remarks. With the finding of the new species, described below, and the transfer of Leptognathia unicinata Hansen, 1913 and L. dentifera G.O. Sars, 1896 there can be no doubt as to the validity of the genus Tumidochelia . There is, however, some doubts as to the family designation of the genus. While currently placed in the family Colletteidae the genus is probably better placed in the Leptognathiidae but this transfer will have to await a comprehensive phylogenetic analysis. The basis for this statement is the pointed nature of the mandibular molar.