Leptocheliinae Lang, 1973

Bird, Graham J., 2019, Tanaidacea (Crustacea: Peracarida) from the Southern French Polynesia Expedition, 2014. I. Tanaidomorpha, Zootaxa 4548 (1), pp. 1-75 : 9

Subfamily Leptocheliinae Lang, 1973

leptocheliid sp. cf. Catenarius Bamber, 2008

( Fig. 3 )

Material examined. MORANE: Non-ovigerous (non-ov.) ♀, 1.1 mm, P. 102325, Stn 59-2.

GAMBIER ISLANDS: Two non-ov. ♀♀, 1.3 and 1.6 mm (left cheliped missing), P. 102326, Stn 66-A.

Distribution and habitat. Morane, and Taravai (Gambier Islands), coral rubble, 10– 29 m.

Remarks. A small and delicate leptocheliid species ( Fig. 3A ). Its place in the leptocheliid classification is somewhat compromised by the lack of males in the sparse material (also precluding full taxonomic treatment) but its essential features can be summarised: antennule ( Fig. 3B ) with four articles (weak between articles 3 and 4) and distinct cap-like terminal segment; antenna ( Fig. 3C ) articles 2–3 each with thin dorsodistal spine; maxilliped endite with two distal setae; cheliped ( Fig. 3D ) basis dorsolateral seta simple, merus with single ventral seta, carpus with group of three ventral setae, chela slender (2.3 times ltb), fixed finger with two ventral setae and three adjacent to incisive margin; pereopod-1 ( Fig. 3E ) merus naked, carpus with long dorsodistal seta, dactylus and unguis subequal, together 1.2 times longer than propodus; pereopod-2 ( Fig. 3F ) ischium with seta, merus with inferodistal seta, carpus with small inferodistal spine and two distal setae, propodus with small inferodistal spine and superodistal seta, dactylus and unguis together half as long as propodus; uropod ( Fig. 3G ) exopod onesegmented, shorter than segment-1 of four-segmented endopod.

Following the extensive revision of the Leptocheliidae by Guţu (2016) this French Polynesian taxon emerges as Catenarius Bamber, 2008 in the key to the Leptocheliinae (Guţu op.cit: p.23, couplet 4) via presence of the long pereopod-1 superodistal seta and four-articled antennule (‘five-articled’ as used by Guţu). Yet, this species differs from the Queensland Catenarius daviei Bamber, 2008 in having no ventrodistal spine on antenna article-2, two maxilliped endite setae (cf. three), pereopod-1 dactylus and unguis subequal in length, and a one-segmented uropod exopod, inter alia. Whether this is within the generic envelope of Catenarius (currently monotypic) or represents a new, but closely allied, genus remains to be determined.

Figures

FIGURE 3. Leptocheliid sp. cf. Catenarius Bamber, 2008 non-ovigerous female (P.102326). A, habitus; B, antennule; C, antenna; D, right cheliped; E, pereopod-1; F, pereopod–2; G, uropod. Scale bars: habitus 0.5 mm, others 0.1 mm.