Tropichelura insulae ( Calman, 1910 )

Coleman, Charles Oliver & Renz, Adina, 2009, Cheluridae *, Zootaxa 2260 (1), pp. 339-343 : 340

Tropichelura insulae ( Calman, 1910)

( Figs 1 , 2 )

Chelura insulae Calman, 1910: 182 , pl. 5, figs 1–6. ― Miller, 1924: 159, pl. 12, figs 1–2. ―J.L. Barnard, 1955: 39. Tropichelura insulae J.L. Barnard, 1959: 6 , figs 2, 4 C–E. ―J.L. Barnard, 1971: 54, fig. 23; ― Cookson, 1991: 140.

― Thomas, 1979: 867.

Not Tropichelura insulae . ― Escobar-Briones et al., 2002: 363 (= T. gomezi Ortiz, 1976 ). ― Ortiz et al., 2007: 490.

Material examined. Male, 5 mm, AM P78978 ( SEL /LIZ-2-6) ; 1 female, 4 mm, AM P78979, ( SEL /LIZ-2- 6) ; 1 male, 23 juveniles, 7 subadults, AM P78980 ( SEL /LZI-2-6) .

Type locality. Christmas Island .

Description. Based on male, 5 mm, AM P78978.

Head. Head with short rostrum and rounded eyes. Antenna 1 shorter than 2; accessory flagellum uniarticulate. Mandible stout, molar triturative. Maxillae 1–2 inner and outer lobes of slender. Maxillipeds with slender inner and outer lobes; palp 4-articulate.

Pereon. Gnathopods 1–2 and Pereopods 3–7 coxae small, wider than long, weakly overlapping. Gnathopod 1 with massive propodus, palm with 5 subacute or rounded teeth and 4 rounded excavations, dactylus with proximal rounded lobe on inner curvature. Gnathopod 2 slender basis, merus, carpus and propodus with long plumose setae. Pereopods 3–4 subequal, basis anterior margin somewhat convexly produced; ischium to dactylus all relatively short. Pereopods 5–7 merus short and widened; carpus subqual to ischium; propodus with row of spiniform setae on posterior margin; dactylus short, stout and curved. Pereopod 7 basis subrectangular, without posterior lobe (but see variations).

Pleon. Pleonite 1 shortest. Pleonite 3 dorsally with 3 spines. Epimeron 1 ventrally rounded. Epimeron 2 angular posteroventrally. Urosomites fused; urosome as long as pleon. Uropod 1 with long peduncle, rami short, outer ramus slightly shorter than inner. Uropod 2 with wide expanded peduncle, outer margin crenulate, rami short, widened, outer ramus shorter than inner. Uropod 3 peduncle short; ramus ovoid, densely bordered with long slender setae. Telson longer than wide, tapering distally, with 4 notches and long distal setation.

Female (sexually dimorphic characters). Based on female 4 mm, AM P78979. Gnathopod 1 propodus smaller than in male, palm entire, slightly convex, with pointed defining process.

Variation. The spines on gnathopod 1 palm are only fully developed in adult males. There is some variation in the width of the basis of pereopod 7: females or subadult males have slender basis and only in the fully developed males is it wide and lobate. The density of the setation on antenna 2 and uropods, especially on the ventral side of uropods 1 and 3, is much higher in the fully developed males.

Remarks. Thomas (1979) compared Tropichelura gomezi Ortiz, 1976 and T. insulae collected in the Caribbean Sea. Both species seem to be rather similar. Within the material of T. insulae from the Great Barrier Reef, all specimens from one location, we found a considerable variability in the density of setation, the morphology of the gnathopod 1 palm and the width of the basis of pereopod 7. It is possible that there is only one variable species, T. insulae , in the genus.

Distribution. Circumtropical. Australia. Queensland: Green Island ( Cookson 1991), Lizard Island (current survey). USA. Hawaii: Honolulu ( Miller 1924). Caroline Islands. Yap and Palau (J.L. Barnard 1959). Mariana Islands. Saipan (J.L. Barnard 1959). Samoa ( Miller 1924). Caribbean Sea: Costa Rica: Limon (J.L. Barnard 1959). Trinidad at Gaspar Grande Island (J.L. Barnard 1959). Puerto Rico at Paraguera (J.L. Barnard 1959). Gulf of Mexico. ( Escobar-Briones et al. 2002). Indian Ocean: Christmas Island ( Calman 1910).

Figures

FIGURE 1. Tropichelura insulae (Calman, 1910), male, 5 mm, AM P78978, Palfrey Island, Lizard Island, Great Barrier Reef.

FIGURE 2. Tropichelura insulae (Calman, 1910), male, 5 mm, AM P78978, Palfrey Island, Lizard Island, Great Barrier Reef.