Tropischyrocerus pugilus, Just, Jean, 2009

Just, Jean, 2009, Ischyroceridae *, Zootaxa 2260 (1), pp. 463-486 : 466-469

publication ID	https://doi.org/ 10.11646/zootaxa.2260.1.27
persistent identifier	https://treatment.plazi.org/id/043B87F2-FF80-B44B-51F6-F9A4FC311295
treatment provided by	Felipe
scientific name	Tropischyrocerus pugilus
status	sp. nov.

Treatment

Tropischyrocerus pugilus sp. nov.

( Figs 2 View FIGURE 2 , 3 View FIGURE 3 )

Type material. Holotype, male, 2.4 mm, AM P71567, Yonge Reef, Half Mile Opening (14°34'19"S 145°36'51"E), Halimeda opuntia (green coralline algae), 9 m, O. Coleman, 5 March 2005 (QLD 1829) GoogleMaps . Paratypes: 1 female with fully developed oostegites, 2.1 mm, AM P71376 (QLD 1810); 1 small male, 1.8 mm, AM P71421 (QLD 1808) .

Etymology. The epithet is from the Latin pugil meaning fist fighter, alluding to the large gnathopod 2 propodus reminiscent of a boxing glove.

Description. Based on holotype, male, 2.4 mm, AM P71567.

Head. E yes 1/3 dorsal length of head, situated partially within lateral lobe of head; lateral cephalic lobes apically acute. Antenna 1 peduncular article 1 distinctly shorter than article 3; flagellum distinctly longer than peduncle article 3, of 4 articles, accessory flagellum directed at 90° to main flagellum, 2-articulate (article 2 minute). (Antenna 2 not known in male.)

Pereon. Gnathopod 1 distinctly smaller than gnathopod 2; coxa of similar length to coxae 2–4; carpus distinctly shorter than propodus; propodus length 1.7 x width, posterodistal margin evenly rounded. Gnathopod 2 subchelate; coxa broader than 1 and 3, width 1.5 depth, ventral margin weakly concave; carpus slightly wider than long, anterior margin broadly rounded; propodus length approximately twice width, broadest proximally, anterior margin broadly convex, posterior margin basically straight, proximally with short forward curved thumb, distally with short conical projection; dactylus distinctly longer than half length of propodus, reaching nearly to propodus thumb. Pereopods 3–4 basis weakly expanded, almost linear; merus weakly expanded. Pereopods 6–7 (5 missing) basis with nearly parallel margins and angular posterodistal corner, with a few setae.

Pleon. Uropod 1 peduncle dorsolateral margin with a few robust setae. Uropod 2 peduncle dorsal margin without setae. Uropod 3 peduncle approximately 3.5 x proximal lateral width, broad proximally, narrowing distally. Telson subtriangular, with single robust seta on each lateral margin.

Habitat. Among the green algae Halimeda and Caulerpa , 9– 16 m.

Remarks. Females of Tropischyrocerus pugilus are similar to males, except for sexually dimorphic much smaller gnathopod 2 with a concave palm, and coxa 2 which in females is slightly longer than wide, evenly rounded ventrally and similar to coxa 3. Basis of pereopods 3–4 are slightly broader than in male.

Coxa 2 in young males is less wide than in large males, and ventral margin concavity is poorly developed. The enlarged gnathopod 2 propodus of large males develops gradually; Fig. 3 M View FIGURE 3 1 G View FIGURE 1 2 View FIGURE 2 shows the gnathopod of a 1.8 mm long male.

Tropischyrocerus pugilus differs from T. socia as follows: antennae shorter, stouter, peduncle of antenna 1 as long as head and first one and a half pereonites (head and first 3 pereonites in T. socia ); coxa 2 in male ventrally concave (straight); gnathopod 2 propodus in male ovoid, thumb forward curved (elongate, thumb perpendicular to propodus posterior margin).

Distribution. Australia. Queensland: Young Reef (current study).