Trapezia tigrina Eydoux and Souleyet, 1842

Trapezia tigrina Eydoux and Souleyet, 1842 View in CoL [Jn: Akahoshi-sangogani]

( Fig. 1B View Fig )

Trapezia tigrina Eydoux and Souleyet, 1842, p.232 View in CoL , pl 2 fig. 2. — Ward, 1939, p. 13, figs. 15–16. — Galil & Lewinsohn, 1984, p.166, fig. 1. — Serène, 1984, pp. 270 & 272 (in keys), 275, fig. 182, pl. 39 figs. C–D. — Castro, 1997b, p.130; 1999, p. 55; 2009, p.276, fig. 2B. — Castro et al., 2004, pp.45 (in key), 54. — Naderloo, 2017, pp.283 (in key), 287, figs. 22.3b, 24.5.

Trapezia punctata Coulon, 1864, p. 569 View in CoL .

Trapezia ferruginea var. rufopunctata (Herbst, 1799) View in CoL : Paulson, 1961 [1875], p. 54, pl. 7 fig. 3.

Trapezia rufopunctata (Herbst, 1799) View in CoL : Klunzinger, 1913, p. 309, pl. 11 fig. 13.

Trapezia cymodoce maculata (MacLeay, 1838) View in CoL : Rathbun, 1930, p.558, pl. 228 figs. 3–4. — Edmondson, 1962, p. 300, fig. 31b.

Trapezia danae Ward, 1939, p.13 View in CoL , figs. 17–18. — Ooishi, 1970, p. 94, pl. 15 fig. 11.

Trapezia wardi Serène, 1971a View in CoL (1970), p. 914, pl. 4 fig. C; 1971b (1969), p. 140, figs. 7–8, 11–12, 17–20, 23, 25. — Sakai, 1976, pp. 506 (in key) & 509 (in English), p. 314 (in Japanese), pl. 181 figs. 3–4.

Material examined. Haha-jima Is. —Diving site Shihon-iwa South (26°38′49″N, 142°08′36″E), Haha-jima I., 1 young 8 (NSMT-Cr 31649; cb 7.3×cl 6.4 mm), 6-VII-2015, H. Komatsu leg.

Remarks. Galil and Lewinsohn (1984) deeply discussed the synonymy of this species based on numerous specimens preserved in many museums, and made clear the confusion with some similarly spotted species, especially Trapezia rufopunctata (Herbst, 1799) . Later, due to the extended works by Castro (1997a, b, 1999, 2009) and Castro et al. (2004), T. punctata Coulon, 1864 , T. danae Ward, 1939 , and T. wardi Serène, 1971 , were reduced to synonyms of T. tigrina .

The size and number of the reddish spots are rather similar in T. tigrina and T. rufopunctata , and considerably variable in the developmental stages in both species. However, the carapace shape is different in both species. The carapace of T. tigrina is not widened anteriorly, with the subparallel anterolateral margins of both sides ( Fig. 1B View Fig ), while in T. rufopunctata , the carapace seems to be wider anteriorly, viz. each anterolateral margin of the carapace weakly directed obliquely outward to the external orbital tooth and each posterolateral margin behind the epibranchial tooth strongly convergent to the carapace posterior margin. The color photographs of both species were finely indicated by Maenosono (2021b, fig. 2A–B for T. tigrina ; fig. 2F for T. rufopunctata ). As also indicated in the present paper ( Fig. 1B View Fig ), the spots are generally larger and fewer than T. rufopunctata , in which the outline of each spot is clear-cut. In life, the spots of T. rufopunctata are deep-red much more than those of T. tigrina .

Distribution. Widely distributed in the Indo-West Pacific, from the Red Sea and the western Indian Ocean to the southern and western Pacific northwards to Japan.