Leptognathiidae Sieg, 1973

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 : 14

Family Leptognathiidae Sieg, 1973

Diagnosis. (Modified from Larsen 2005).

Female. Medium body calcification. No plates in carapace. Eyes and eye-lobes absent. Pereon with six free pereonites. Pereonite 1 not reduced. Pleon with five free pleonites, as wide as pereon, no articulated setae on pleonites. Antennule with four articles. Antenna with 5–6 articles, article 3 without spiniform setae dorsally. Molar process of mandible pointed. Labium with one pair of lobes, medial spiniform setae absent. Maxillipedal bases fused, endites not fused, narrower than basis, without setose or serrated antero-lateral corners, flat setae, or denticles. Cheliped slender and attached via sclerite, fixed finger and dactylus elongated or simple. Marsupium consisting of four pairs of oostegites. Pereopod coxae present or absent on pereopods 1–3, but always absent on pereopods 4–6, dactylus and unguis not fused. Pleopods well developed or absent. Uropodal endopod with two articles, exopod with one or two articles.

Male (terminal male): body significantly shorter than female. Pereonites less, pleonites more developed than in female. Antennule with more than seven articles, densely packed with aesthetascs. Mouthparts reduced. Cheliped not enlarged. Pleopods well developed.