Leptanthura calcis, Kensley & Schotte, 2000

Kensley, B. & Schotte, M., 2000, New species and records of anthuridean isopod crustaceans from the Indian Ocean, Journal of Natural History 34, pp. 2057-2121 : 2107

Leptanthura calcis sp. nov.

( Figures 33, 34)

Type material. HOLOTYPE: USNM 253148 , non-ovigerous m 3.4 mm, sta K-AL-87, coral rubble, fore-reef slope, Picard Is, Aldabra, 15 m, 12 March 1986 . PARATYPES: USNM 253149 , one non-ovigerou s m 3.0 mm, sta K-AL-115, coarse sand and coral rubble, patch reef in lagoon, Aldabra, 2±3 m, 6 April 1987 . USNM 253150 , two non-ovigerous m 3.5 mm, sta F-1-87, intertidal rubble from reef crest, Picard Is., Aldabra, 27 March 1987 .

Diagnosis. Cephalon with low rounded rostrum; eyes lacking. Telson slightly more than twice longer than basal width, with slight widening in posterior half, posterior margin broadly rounded with few setae. Antennular peduncle with basal article longer and wider than two distal articles together; ¯agellum of three articles, terminal article bearing three aesthetascs. Antennal ¯agellum of four articles. Mandibular palp with article 2 longest and widest; terminal article with two short distal setae. Maxillipedal palp having two tiny distal articles. Pereopod 1, carpus triangular, lacking free anterior margin, with single posterodistal seta; propodus expanded, palm slightly concave, lined with seven short spinulose setae, posteriormost seta longest, situated on short lobe; unguis about one-third length of rest of dactylus. Pereopod 2, propodus much less expanded than in pereopod 1, with three spinulose setae plus elongate sensory seta on palm. Pereopod 3, propodus slightly less expanded than in pereopod 2, with two spinulose setae plus elongate sensory seta on palm. Posterior pereopods with carpus triangular, lacking free anterior margin; propodus about three times longer than wide, with single posterodistal seta. Pleopod 1, exopod operculiform, 2.5 times wider than endopod, latter with three distal plumose setae. Uropodal exopod ovate, apically acute, with few elongate marginal setae; endopod almost twice longer than basal width, with numerous elongate distal setae.

Remarks. Leptanthura calcis belongs to the group of species having small, non-subcircular uropodal exopods, of which three have been recorded from the Indo-West Paci®c Ocean: L. agulhasensis Kensley, 1975 , from South Africa, has a posteriorly more triangular and acute telson and a more triangular and acute uropodal endopod; L. minuta Kensley, 1978a , from Natal, South Africa, has an evenly ovate, posteriorly rounded telson. L. orientalis Barnard, 1925 , from Singapore, (the type of which lacks telson and uropods, see Kensley, 1987: 124), has a narrower pereopod 1 propodus with fewer setae on the palm and more slender and more spinose carpi and propodi of the posterior pereopods.

Etymology. The speci®c name derives from the Greek word `chalix ’ for a pebble or stone and refers to the rubble habitat.