Araleptochelia, Błażewicz-Paszkowycz & Bamber, 2012

Błażewicz-Paszkowycz, M. & Bamber, R. N., 2012, The Shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae), Memoirs of Museum Victoria 69, pp. 1-235 : 113

Genus Araleptochelia gen. nov.

Diagnosis. Female with 4-articled antennule, third article longer than second; antenna 6-articled, articles 2 and 3 with slender distal spines, article 2 without ventral spine; maxilliped basis with four long setae extending to half length of second palp article, endites distally with single seta and three slender spatulate spines; cheliped relatively slender, merus covering less than half of ventral margin of carpus, propodus (palm of chela) nearly twice as long as wide; dactylus plus unguis on first pereopod 1.5 times as long as propodus; merus of pereopods 2 and 3 with ventrodistal spine about two-thirds as long as carpus; pleopod without inner plumose seta on the pleopod endopod; uropod exopod 1-segmented, endopod 5-segmented, with all segments elongate (more than four times as long as wide). Otherwise typical of the family. Male showing dimorphism in the antennule with secondary segmentation of the flagellum to more than 17 segments, proximal flagellum segment bearing large dorsodistal spine almost as long as flagellum; cheliped slender, sinuous; posterior pereopods without flange on basis. Sub-adult male with five-articled antennule.

Type species: Araleptochelia macrostonyx sp. nov. by monotypy,

Etymology. from the Greek araeos – thin, as is the chela of the female (and the proximal uropod endopod segments) – and “ Leptochelia ”, to which genus it is closest (female).

Remarks. Ostensibly, the species described below has the gross appearance of a typical Leptochelia ; females of that genus are remarkably conservative in their morphology, a factor which in the past has lead to over-synonymization. The present species has a sufficient number of distinguishing characters, notably the slender chela (somewhat reminiscent of that of a typhlotanaid); the very slender distal spines on the second and third peduncle articles of the antenna; the proportionately very long dactylus and unguis of pereopod 1; the long ventrodistal spines on the merus of pereopods 2 and 3; the lack of an inner plumose seta on the pleopod endopod; and the elongate proximal uropod segments, that it warrants separation into a distinct genus.

The spination/setation of the antennal peduncle articles is more typical of such genera as Konarus Bamber, 2006 , Pseudonototanais Lang, 1973 and Parakonarus Bird, 2011 rather than of Leptochelia , while the proportions of the dactylus and unguis of pereopod 1 are more typical of Leptochelia .

The mouthparts are typical of Leptochelia , inter alia, and while the maxilliped basis has four distal setae in the only known species (thus distinguishing it from such other leptocheliid genera as Heterotanais and Pseudoleptochelia ), the number of these setae is known to be variable in, for example, Leptochelia (e.g. Bamber, 2008), so cannot as yet be regarded as diagnostic. While the chela of the male may be regarded as somewhat intermediate between that of the L. savignyi - type and that of the L. minuta - type, theextreme secondary segmentation of the antennule flagellum, with an extraordinarily long spine on the first flagellum segment, reinforces the difference between this taxon and species of Leptochelia .