Alloleptochelia Guţu, 2016

Tzeng, You-Wei, Wei, Chih-Lin, Ma, Lin & Li, Xinzheng, 2023, Three new species of Paratanaoidea (Crustacea, Tanaidacea) from the South China Sea, Zootaxa 5375 (1), pp. 1-30 : 2-4

Genus Alloleptochelia Guţu, 2016

Type species. Alloleptochelia monotricha Guţu, 2016

Diagnosis (modified and updated from Guţu 2016, new features highlighted in boldface). Female: Body dorsoventrally flattened, usually seven to nine times longer than wide, occasionally less than six times longer than wide. Carapace ovate, at most 1.4 times longer than wide. Pereonites usually wider than long, rarely some medial pereonites longer than wide. Antennule three- or four-articled with distal cap-like segment. Antenna six-articled; articles 1–3 short; sometimes article-1 with one short ventrodistal seta; article-2 with one dorsodistal and one ventrodistal simple or spiniform setae, sometimes with additional one or two distal setae or small spiniform setae; article-3 with only one dorsodistal spiniform setae. Mouthparts as in other leptocheliids; maxilliped endite with one lateral seta, distal margin with two long and (sometimes) one short linguiform spiniform setae. Cheliped basis with one outer simple seta; merus usually with three unequal ventral setae, occasionally with two or more than three ventral setae; carpus with six to eight spinules (occasionally absent) on all length of dorsal margin; fixed finger with five setae. Pereopods 1–3 basis with proximodorsal seta. Pereopod-1 merus usually with one dorsodistal and one ventrodistal seta (occasionally one or both absent); carpus with four or five unequal distal setae; dactylus longer than unguis. Pereopods 2 and 3 merus with one (occasionally two) small ventrodistal spiniform seta, and sometimes with one additional dorsodistal seta (only on pereopod-2); pereopod-2 propodus dorsal margin with two subdistal setae, ventral margin with one small subdistal spiniform seta; pereopod-3 propodus as pereopod-2 but dorsal margin with one less seta. Pereopods 4–6 basis swollen, sometimes with one or two setae on distal half; ischium with two ventral setae; merus with two ventrodistal spiniform setae and accidentally with an additional dorsodistal seta. Pleopods as in other leptocheliids. Uropod peduncle naked; exopod with one or two articles; endopod with six (rarely five) articles. Male: Body robust, usually five to seven times longer than wide, occasionally less than five or nearly ten times longer than wide. Carapace ovate or occasionally pear-shaped, longer than wide, posterior half slightly or remarkably wider; rostrum broad, round in top or relatively flattened. Eye lobe larger than that of female; eye pigmented. Pereonites wider than long. Antennule multi-articled, shorter than body; peduncle three-articled, at least twice as long as carapace; flagellum shorter than peduncle article-1, with more than six articles. Antenna six-articled; each of the first three articles short, with setation similar to that of female. Mouthparts reduced, only rudimentary maxilliped and normal epignath present. Cheliped slender and very long, as long as body or occasionally slightly shorter; basis shorter than carapace; merus short with three or more short setae, occasionally with two short setae; carpus slender and very long, about as long as or slightly longer than antennule peduncle, more than ten times longer than wide, with around of eight or occasionally less setae on dorsal margin and other some on ventrodistal half; propodus slender, about as long as carpus; palm slightly wider distally, about four or five (or occasionally less than four) times longer than distal width; setal row approximately parallel with dorsal margin of palm; fixed finger slender, rarely shorter than propodus palm, usually with small proximo-inner apophysis and five setae on distal half; dactylus slender, slightly longer than fixed finger, with small spines on inner margin. Pereopod-1 merus with one dorsodistal seta, usually with one ventrodistal seta. Pereopods 2–3 coxa, basis and merus, and propodus similar to those of female. Pereopods 4–6 merus with spiniform setae stronger than those of female. Pleopods narrower than those of female. Uropod similar to that of female, but peduncle with some short distal setae and endopod with more and longer setae.

Remarks. The genus Alloleptochelia includes ten species: A. angusta Guţu, 2016 ( Tanzania), A. erythraea ( Kossmann, 1880) ( South Africa), A. evansi ( Edgar, 2012) (western Australia), A. heardi Guţu, 2016 (Bunaken Island, Indonesia), A. helenae Guţu, 2011 (Bunaken Island, Indonesia), A. insolita Guţu, 2016 ( Réunion Island, western Indian Ocean), A. longimana ( Shiino, 1963) (Hon Tre Island, Vietnam), A. monotricha Guţu, 2016 (Bunaken Island, Indonesia), A. multiarticulata Guţu, 2016 (Lifou Island, Coral Sea) and the new species, A. falciformes sp. nov. (see below), all distributed in the Indo-West Pacific Ocean ( Bamber 2006; Jarquín-González et al. 2015).

In order to accommodate the features of A. falciformes , A. angusta , A. evansi , A. helenae , and A. multiarticulata that deviate from the original generic diagnosis ( Bamber 2006; Edgar 2012; Guţu 2011, 2016; see below), the generic diagnosis has been slightly amended. This amendment includes wider ranges of body length-to-width ratios, setal numbers on the cheliped merus, carpus, and pereopod-1 merus in both sexes, alternative shapes of the male carapace and cheliped, as well as a wider range of numbers of antennule flagellum articles in males.