Apanthuroides calculosa, 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 : 2068-2070

Apanthuroides calculosa sp. nov.

( Figures 7, 8)

Type material. HOLOTYPE: USNM 253099 , ovigerous m 4.7 mm, sta F-8-87, Passe Hoareau channel, Ile Malabar, Aldabra, coral rubble, 0.3 m, 11 April 1987 . PARATYPE: USNM 253100 , non-ovigerous m 3.3 mm, same data as holotype .

Other material examined. USNM 253101 , non-ovigerous m 3.0 mm, sta K-AL-13, Cinq Cases , South Is., Aldabra, coral rubble, 6 m, 3 April 1983 . USNM 253102 , three non-ovigerous m 3.3 mm, sta K-AL-40, reef ¯at, Ile Picard, Aldabra, intertidal, 12 April 1983 . USNM 253103 , non-ovigerous m 2.9 mm, sta K-AL-49, coral rubble, Passe Femme, Aldabra, intertidal, 14 April 1983 . USNM 253104 , nonovigerous m 2.9 mm, sta K-AL-107, coral rubble, Grande Passe , Aldabra, 6 m, 21 April 1986 . USNM 253105 , three non-ovigerous m 4.0 mm, sta K-AL-112, coral rubble, Mahe Beach , Mahe Is., Seychelles, 8 m, 2 April 1986 . USNM 253106 , three manca 2.8±3.0 mm, sta K-SEY-15, Anse aÁ la Mouche, Mahe Is., Seychelles, 3 m, 1 May 1984 . USNM 253107 , l3.0 mm, coral rubble, reef crest, Picard Is., Aldabra, 3 April 1983 .

Diagnosis. Non-ovigerous female: Body about ten times longer than wide. Integument pitted, more so in posterior than in anterior half. Head with weakly pigmented eyes; low triangular rostrum not reaching anteriorly as far as anterolateral lobes. Pereonite 7 about two-thirds length of pereonite 6, with pereopods present. Pleonites 1±5 fused, with dorsal pits faintly indicating original pleonites. Telson basally broad, tapering posteriorly, with posterior margin evenly rounded, setose; strong middorsal ridge running almost entire length. Antennule with basal article slightly longer and wider than two distal peduncle articles; ¯agellum of ®ve articles, two distal articles together bearing ®ve aesthetascs. Antenna with article 2 longest; ¯agellum of six setose articles. Mandible typical of genus; distal palp article bearing three setae; molar process styliform on one side, represented by tiny`thorn’ on other. Maxilla elongate±slender, distal spine blunt, with four smaller spines present. Maxilliped with well developed endite having two distal spinules; distal article broadly rounded, with three distal marginal setae. Pereopods 1±3 of similar size and proportions. Pereopod 1, propodus not expanded, palm concave, bearing one posterodistal simple seta, three submarginal setae. Pereopod 2 with stout serrate posterodistal seta. Pereopods 4±7 with posterodistal serrate seta on propodi and carpi; latter with anterior margin shorter than posterior margin. Pleopod 1 protopod with three retinaculae; endopod about two-thirds width of, and slightly longer than exopod; both rami forming operculum. Uropodal protopod with ®ve elongate plumose setae on outer margin, single plumose seta on inner distal angle; endopod longer than wide, distal margin setose, rounded; exopod not reaching midlength of endopod, basally narrowed, widest at midlength, distally somewhat tapered.

Male: Antennular ¯agellum of eight articles, each bearing whorl of aesthetascs. Antennal ¯agellum of seven articles. Eyes enlarged, occupying most of lateral surface of cephalon, not quite meeting middorsally. Pereopod 1, propodus bearing ®ve stout fringed setae in distal half of posterior surface.

Remarks. In general proportions, and in the integumental pitting, A. calculosa

FIG. 8. Apanthuroides calculosa sp. nov.: (A) lpereopod 1; (B) m pereopod 1; (C) pereopod 2; (D) pereopod 6; (E) left mandible; (F) right mandible and maxilla; (G) maxilliped.

closely resembles A. W jiensis ( Kensley, 1979) from Fiji. The latter, however, has a three-articulate ¯agellum of the antenna (six articles in the present species) and a three-articulate ¯agellum of the antennule (four in the present species). Apanthuroides foveolata ( Kensley, 1978b) from deep water oOE the east coast of South Africa and A. spathulicauda WaÈgele, 1981b from the Mediterranean both possess ®nely dentate telsonic and uropodal margins. Apanthuroides millae Menzies and Glynn, 1968 from the Caribbean (and also the type species of the genus) is a squatter species with smaller pereonite pits.

Etymology. The speci®c name derives from the Latin, calculosus , meaning gravelly or pebbly, referring to the rubble habitat of the species.