Cymo quadrilobatus Miers, 1884

Cymo quadrilobatus Miers, 1884 View in CoL [Jp name: Awahada-saimogani]

( Fig. 1E View Fig )

Cymo andreossii var. quadrilobatus Miers, 1884, p.533 View in CoL .

Cymo quadrilobatus View in CoL : Alcock & Anderson, 1894, p.200. — Alcock, 1898, p.175.— Borradaile, 1902, p.251. — Nobili, 1906a, p.272. — Rathbun, 1907, p.53, pl. 1 fig. 7; 1911, p.227. — Bouvier, 1915, p.281. — Ward, 1942, p.100. — Tweedie, 1950, p.123. — Holthuis, 1953, p.19. — Guinot, 1958, p.183, fig. 27; 1962, p. 239.— Sankarankutty, 1961, p.129, fig. 1G. — Takeda, 1975, pp.141, 196, 1 ununmbered fig.; 1983, pp.141, 195, 1 unnumbered fig. — Dai & Lan, 1981, p.125, figs. 5–6, pl. 1 fig. 6. — Serène, 1984, pp.32 (in keys), 34, fig. 9, pl. 2 figs. E–F. — Dai et al., 1986, pp.320 (in key), 322, pls. 46 fig. 5. — Nagai & Nomura, 1988, p. 208, 1 unnumbered fig. — Dai & Yang, 1991, pp.344 (in key), 346, pl. 46 fig. 5. — Poupin, 1996, p.38. — Kawamoto & Okuno, 2003, p.134, 1 unnumbered fig. — Marumura & Kosaka, 2003, p.55. — Poupin et al., 2013, p. 10. — Brösing et al., 2014, p. 207 View Cited Treatment , figs. 11–12. — Mendoza et al., 2014, p.278, fig. 2B. — Poupin et al., 2018, p. 46, fig. 14B.ɹ

Material examined. Chichi-jima Is. — Nishi-jima I., 1 ♀ (NSMT-Cr 32150; cb 17.3×cl 16.5 mm), 29-VI-1976, M. Takeda leg.

Remarks. The present specimen ( Fig. 1E View Fig ) identified with Cymo quadrilobatus seems to be distinct from the typical specimens having the subcircular carapace contour appeared in some papers (e.g., Serène, 1984, pl., 2 figs. E–F; Mendoza et al., 2014, fig. 2B; Poupin et al., 2018, fig. 14B), having the narrower, barrel-shaped carapace. However, considering the photographs given by Brösing et al. (2014, fig. 11), the carapaces of the young and female specimens are apparently narrower than the subcircular carapaces of the adult males, with morphological variation according to the developmental stages and sexes.

This species is the most characteristic among five congeneric species, but one of them, C. tuberculatus Ortmann, 1893 , was poorly known only with the records by Ortmann (1893) and Serène (1984). The original description based on a male from the Maldive Archipelago is short and almost applicable also to C. andreossyi (Audouin, 1826) mentioned for comparison. Alcock (1898) mentioned, without specimens, that it may perhaps be identical with C. quadrilobatus . Only the reliable literature may be Serène (1984), in which each frontal lobe is marginally concave and gives the front a quadrilobed aspect in C. quadrilobatus , and the frontal lobes are almost straight and gives the front a bilobed aspect in C. tuberculatus . This character may be also exposed to variations similar to the carapace proportion, but in this female each frontal lobe is armed with a tubercle at each end and supplemented with a small tubercle in the middle. The G1 of C. tuberculatus illustrated by Serène (1984, fig. 10) has no distal beak and quite different from the figures of C. quadrilobatus illustrated by Guinot (1958) and reproduced by Serène (1984), in which the curved beak is strongly developed. In the G1 figure of C. tuberculatus illustrated by Serène (1984, fig. 10), the distal part is concealed and rather obscure with hairs and seems to be somewhat damaged, so that the reconfirmation is necessary whether the distal beak is normal and figured accurately or not.

In the present specimen preserved so long in ethyl alcohol, four spots on the mesogastric, cardiac and each posterior branchial region are still remained as pale brick red ( Fig. 1E View Fig ).

Distribution. Widely distributed in the Indo-West Pacific from the Red Sea and the western Indian Ocean to the South and West Pacific. In Japanese waters, it is found in the Ryukyu Islands as associates of scleractinian corals.

It is noted that Takeda and Komatsu (2023) so carelessly overlooked the record of this species from Futami Bay, Chichi-jima Island, by Marumura and Kosaka (2003).

Gaillardiellus rueppelli ( Krauss, 1843) View in CoL [Jn: Awatsubu-ougigani] ( Figs. 1D View Fig , 6C–D View Fig )

Cancer (Aegle) rüppelli Krauss, 1843, p. 28 , pl. 1 fig. 1.

Actaea ruppellii : A. Milne-Edwards, 1865, p.270. — Odhner, 1925, p.45, pl. 4 fig. 6 [text-fig. 4 = Gaillardiellus alphonsi (Nobili, 1905) View in CoL ].

Actaea rüppellii : Barnard, 1950, pp.228 (in key), 235, figs. 37d, 43i–j.

Gaillardiellus rueppelli View in CoL : Guinot, 1976, p.254, figs. 42A, 43a, 44B, pl. 126 fig. 1a. — Serène, 1984, p.118, fig. 71, pl. 15 fig. F. — Lee et al., 2012, p.117, figs. 1–2. — Mendoza et al., 2014, p.275, fig. 1A. — Marumura & Takeda, 2015, p.5, fig. 5E–F. — Naderloo, 2017, p. 251, figs. 21.20c, 21.24. — Takeda & Komatsu, 2018, p.160, fig. 1B. — Poupin et al., 2018, p.50, fig. 14J. — Maenosono, 2021a, p. 26, figs. 1E–F, 4E–I, 5.

Gaillardiellus rüppelli View in CoL : Muraoka, 1998, p.42. — Neumann & Spiridonov, 1999, p. 32.

Material examined. Haha-jima Is. —Diving site Hirane (26°34′08″N, 142°12′49″E), Imoto-jima I., 20–25 m, 1 ♂ (NSMT-Cr 31670; cb 23.4×cl 17.7 mm), 14-VII-2016, H. Komatsu leg.

Remarks. Guinot (1976) accommodated three species and one subspecies, Cancer (Aegle) rüppellii Krauss, 1843 , Actaea alphonsi Nobili, 1905 , A. ruppelli orientralis Odhner, 1925 , and A. superciliaris Odhner, 1925 , to the new genus Gaillardiellus . In the paper, G. alphonsi and G. superciliaris were dealt as distinct two species, but suggested to be possibly synonymous with each other. Serène (1984) and Maenosono (2021a) followed Guinot (1976) and treated G. superciliaris as synonymous with G. alphonsi . Among all the known Gaillaridiellus species including G. bathus Davie, 1997 , later described, the carapace anterolateral teeth and the external orbital tooth are united to be four in G. alphonsi and G. superciliaris instead of five in other species. In these two species, the other features seem to be mostly common following the literature concerned, and therefore the synonymization is reasonable.

The present specimen is characteristic in having the carapace, chelipeds and ambulatory legs heavily covered with longish stiff hairs, most of which arise as tufts of some hairs around the granules ( Figs. 1D View Fig , 6C View Fig ). The carapace anterolateral margin is divided into five teeth including the external orbital tooth, all of which are formed with clusters of several pearly granules ( Fig. 6D View Fig ). Marumura and Takeda (2015) recorded the specimens from off Pacific coast of Honshu and the northern Ryukyu Islands, Japan, and the Seychelles in the western Indian Ocean, with the photographs of the male specimen in dorsal and ventral views. The present specimen agrees well with these photographs.

Distribution. Widely distributed in the Indo-West Pacific, from the western Indian Ocean to the Tuamotu Islands, the Micronesian islands, Hawaii and the Ryukyu Islands in the Pacific Ocean. The known locality in Japanese waters is Iheya Island, north of Okinawa-jima Island in the Ryukyu Islands ( Maenosono, 2021a).