Chevalia tenuis, Myers, 2009

Myers, Alan A., 2009, Chevaliidae *, Zootaxa 2260 (1), pp. 344-347 : 344-347

Chevalia tenuis sp. nov.

( Figs 1 , 2 )

Type material. Holotype, male, 2.5 mm, AM P 71428, Yonge Reef, Half Mile Opening (14 o 34.556’S 145 o 36.726’E), Halimeda sp. (green coralline alga), 16 m, P. B. Berents, 4 March 2005 (QLD 1808) . Paratype: 1 female, AM P 77549, same data as holotype .

Additional material examined. 3 males, 3 females, AM P 77551 (JDT/LIZ 3) ; 1 male, 1 female, AM P 77550 (JDT/LIZ 7) ; 1 female, AM P 70613 (QLD 1621) ; 1 male, AM P 71510 (QLD 1823) ; 1 female, AM P 77552 ( SEL / LZI 4-2 ) .

Type locality. Yonge Reef , Lizard Island, Queensland, Australia (14 o 34.556’S 145 o 36.726’E) .

Etymology. From the latin ‘ tenuis’ meaning slender, referring to the attenuated appearance of this species.

Description. Based on holotype, male, 2.5 mm, AM P71428.

Head. Head eyes small (distinctly less than 1/4 head length), partially within the lateral lobe of the head; lateral cephalic lobes rounded. Mandible palp article 3 subequal in length with article 2. Antenna 1 peduncular article 1 distinctly shorter than article 3; accessory flagellum 2-articlulate. Antenna 2 half body length, peduncular articles 4–5 with 4 or more rows of setae per article; flagellum distinctly longer than peduncular article 5.

Pereon. Gnathopod 1–2 & Pereopods 3–4 coxae of similar size. Gnathopod 1 smaller than gnathopod 2; carpus subequal in length to propodus; propodus narrow. Gnathopod 2 propodus subrectangular, twice length of carpus, posterodistal corner with triangular tooth, palm weakly sinuous; dactylus short (distinctly half or less than half length of propodus). Pereopods 3–4 merus elongate, weakly expanded and scarcely overlapping carpus. Pereopods 5–7 basis posterior margin with numerous setae. Pereopods 5–6 dactylus with accessory spine. Pereopod 5 basis distally expanded.

Pleon. Urosomites 1–2 without dorsolateral spines. Uropod 1 peduncle without distoventral spine; rami subequal in length. Uropod 2 peduncle without distoventral spine; rami distinctly unequal in length. Uropod 3 biramous; peduncle subequal in length to the inner ramus; both rami well developed; outer ramus with terminal fine setae.

Female (sexually dimorphic characters). Not sexually dimorphic.

Habitat. Among coral rubble and coralline algae.

Remarks. This species resembles C. aviculae Walker, 1904 from Sri Lanka and a species described from Fiji by Myers (1985), under the name C. aviculae Walker. It differs from these two species in its more slender build: elongate antennae, long slender pereopods 3–4 but much shorter, stouter uropod 3 rami. The male gnathopod 2 propodus differs from both species in its more pronounced, acute, posterodistal spine and less sinuous palm. It also resembles C. pacificus Myers, 1995 from Papua New Guinea from which it differs in the subquadrate posterodistal corner of pereopod 7 as well as in its short, stout, uropod 3 rami.

Distribution. Australia. Queensland: Lizard Island (current study).

Figures

FIGURE 1. Chevalia tenuis sp. nov., holotype, male, 2.5 mm, AM P71428, Yonge Reef, Lizard Island, Great Barrier Reef.

FIGURE 2. Chevalia tenuis sp. nov., holotype, male, 2.5 mm, AM P71428, Yonge Reef, Lizard Island, Great Barrier Reef.