Carpias cf. algicola (Miller, 1941)

Kensley, B & Schotte, M, 2002, New species and records of Asellota from the Indian Ocean (Crustacea: Peracarida: Isopoda), Journal of Natural History 36, pp. 1421-1461 : 1425

Carpias cf. algicola (Miller, 1941)

(gure 3)

Janira algicola Miller, 1941: 317 , gure 4.

Carpias algicola: Kensley and Schotte, 1989: 83 , gure 38.

Bagatus algicola: Pires, 1982: 247 , gures 47–62.

Material examined. USNM 253312 , 1720 specimens from 56 stations on Aldabra Atoll , intertidal to 22 m ; USNM 253313 , 500 specimens from 20 stations from Mahé Island, intertidal to 6 m ; USNM 253314 , 34 specimens from algal turf, Mayotte Island, Comoros, 3–5 m, 14 March 1991 ; USNM 253315 , 150 specimens , IIOE sta HA-32, sh poison station on small reef, Strait of Jubal , northern Red Sea, 27ss16¾ 38 ² N, 33ss47¾ 01 ² E, 0–8 m, coll. H. A. Fehlmann, 4 January 1965 ; USNM 253316 , 17 specimens Arsenal Bay , Mauritius, 15 June 1963 .

Previous records. Caribbean; Gulf of Mexico; Florida Keys; Hawaii; India.

Diagnosis. Pereopod 1 in male, carpus about same width proximally as distally, with two strong distal teeth on posterior margin; propodus narrow, curved, tapering slightly, reaching proximally to merus; dactylus very short, biunguiculate in immature animal, becoming reduced to cluster of simple setae in mature animals.

Remarks. Identi cation of what is frequently the most abundant shallow water isopod in tropical regions is complicated by the variation with growth of the male pereopod 1. There is a progressive decrease and eventual loss of the dactylus, from a small biunguiculate article (at total length of about 1.5 mm), to the point where the dactylus is represented by a clump of elongate simple setae (total length 2.4–2.7 mm) (see Pires, 1982, gures 56–62). Given this variability with age, any species distinguished by characters of the male rst pereopod must be treated with caution. A further complication is the fact that species of Carpias are known to raft on oating algae (e.g. Kensley et al., 1995), thereby making even a tentative identi- cation based on geography impossible. Given this rafting ability, it is possible that several species of Carpias have a tropical/subtropical distribution in several oceans. The male rst pereopod of what is assumed to be C. algicola from the Caribbean ( Belize and Cuba), and the Indian Ocean (Aldabra and Mahé), at various total body lengths is illustrated to demonstrate the variability mentioned above.