Actaeodes consobrinus (A. Milne-Edwards, 1873 )

Actaeodes consobrinus (A. Milne-Edwards, 1873) View in CoL [Jn: Kobu-samehada-ougigani]

( Fig. 1E–F View Fig )

Actaea consobrina A. Milne-Edwards, 1873, p.79 View in CoL . — Odhner, 1925, p.67, pl. 4 fig. 14. — Sakai, 1939, p. 491, pl. 94 fig. 2. — Serène & Bui, 1959, p. 291, fig. 2A. — Ooishi, 1970, p. 92, pl. 14 fig. 7. — Deb, 1989, pp.7 (in key), 12, pl. 3 fig. 7.

Actaeodes consobrinus View in CoL : Guinot, 1976, p.246, pl. 15 fig. 5. — Sakai, 1976, p.448 (in English), p.270 (in Japanese), pl. 158 fig. 3 — Serène, 1984, pp.133 (in key), 134 (in key), 135, pl. 18 fig. C.

Actaea suffuscula Rathbun, 1911, p.220 View in CoL , pl. 17 figs. 10–11.

Material examined. Chichi-jima Is. —Futami Bay, Chichi-jima I., on buoy, 2ƏƏ (cb 7.9×cl 5.6mm; cb 8.5×cl 5.9mm), 1 ovig.8 (cb 8.0×cl 5.4mm), NSMT-Cr 6874, 17-V-1975, Y. Kurata leg. ; Noyagi-zaki (27°04′30″N, 142°11′05″E), Chichi-jima I., 12 m, 1 Ə (NSMT-Cr 31653; cb 6.5×cl 4.4 mm), 10-XI-2013, H. Komatsu leg. GoogleMaps ; Hitomaru-jima I. (27°07′04″N, 142°11′27″E), 6–8 m, 2ƏƏ (cb 6.3×cl 4.3 mm; cb 8.4×cl 5.9 mm), 2 88 (cb 8.4×cl 6.1 mm; cb 8.4×cl 6.0 mm), 1 ovig.8 (cb 6.5×cl 4.4 mm), NSMT-Cr 31654, 29-VI-2014, H. Komatsu leg.

Haha-jima Is. —Diving site Shihon-iwa North (26°38′56″N, 142°08′37″E), Haha-jima I., 1 ♂ (NSMT-Cr 31655; cb 5.4×cl 4.2 mm), 1 ♂ (cb 5.2×cl 3.7 mm), 2 ovig. ♀♀ (cb 5.5×cl 4.1 mm; cb 6.0×cl 4.5 mm), NSMT-Cr 31656, 2-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Big Beach (26°36′01″N, 142°08′13″E), Mukou-jima I., 3 ♂♂ (cb 5.2×cl 3.9 mm —cb 6.5×cl 5.0 mm), 1 ovig. ♀ (cb 6.5×cl 4.7 mm), 2 ♀♀ (cb 6.5×cl 4.5 mm; cb 8.5×cl 5.3 mm), NSMT-Cr 31657, 2-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Shihon-iwa South (26°38′49″N, 142°08′36″E), Haha-jima I., 1 ♀ (NSMT-Cr 31658; cb 7.6×cl 5.2 mm), 3-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Nishi-hana (26°36′40″N, 142°07′40″E), Mukou-jima I., 2 ♂♂ (NSMT-Cr 31659; cb 5.3×cl 3.5 mm; cb 5.7×cl 4.5 mm), 4-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Zakuzaku (26°35′19″N, 142°08′41″E), Hira-shima I., 1 young ♂ (cb 3.7×cl 2.7 mm), 1 young ♀ (cb 5.3×cl 4.0 mm), NSMT-Cr 31660, 4-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Shihon-iwa South (26°38′49″N, 142°08′36″E), 1 ♂ (NSMT-Cr 31661; cb 8.2×cl 5.4 mm), 1 ♀ (NSMT-Cr 31662; cb 6.4×cl 4.8 mm), 6-VII-2015, H. Komatsu leg. GoogleMaps ; Diving site Blue Ribbon (26°34′03″N, 142°12′48″E), Imoto-jima I., 15–17 m, 3 ♂♂ (cb 5.9×cl 4.6 mm —cb 9.0×cl 6.3 mm), 1 ovig. ♀ (cb 7.2×cl 5.4mm), NSMT-Cr 31663, 11-VII-2016, H. Komatsu leg. GoogleMaps ; Diving site Uentoro (26°39′33″N, 142°10′14″E), Haha-jima I., 12–15 m, 2 young ♂♂ (cb 4.0×cl 2.6 mm; cb 3.5×cl 2.7 mm), 1 ♀ (cb 6.0×cl 4.0 mm), NSMT-Cr 31664, 12-VII-2016, H. Komatsu leg. GoogleMaps ; Diving site Uentoro (26°39′28″N, 142°10′35″E), 14–20 m, 2 ♂♂ (cb 7.1×cl 4.8 mm; cb 8.1×cl 5.6 mm), 1 ovig. ♀ (cb 5.7×cl 4.2 mm), NSMTCr 31665, 12-VII-2016, H. Komatsu leg. GoogleMaps ; Diving site Blue Ribbon , Imoto-jima I., 12–14 m, 5 ♂♂ (cb 5.2×cl 3.6 mm —cb 10.1×cl 6.6 mm), 2 ovig. ♀♀ (cb 5.8×cl 3.6 mm; cb 5.1×cl 3.1 mm), NSMT-Cr 31666, 14-VII-2016, H. Komatsu leg. ; Diving site Hirane (26°34′08″N, 142°12′49″E), Hira-shima I., 20–25 m, 1 young ♂ (NSMT-Cr 31667; cb 4.3×cl 2.7 mm), 14-VII-2016, H. Komatsu leg. GoogleMaps

Remarks. As recorded above, the biggest specimen, male, is 10.1 mm in carapace breadth (cb), and six ovigerous females are within the range of cb 5.1–7.2 mm. In this small species, the carapace dorsal surface is distinctly separated into raised regions by the wide and deep furrows, with rough appearance as a whole. Most remarkable characteristic for this species is, as mentioned by Serène (1984) and seen in Nagai and Nomura (1988) and also in this paper ( Fig. 1F View Fig ), the presence of several blackish spots arranged longitudinally on the carapace median and lateral parts. The blackish color is more or less spotted, but the spots are sometimes variable in the size and shape, being confluent longitudinally with each other to form some longitudinal lines ( Fig. 1F View Fig ). The detailed pattern and size of blackish color are variable as such, and followed usually with some yellowish, irregular blotches along dark spots.

There is no doubt for the species identification, but with slight hesitation for its generic status because of different carapace ornamentation and hairiness from most of the Actaeodes species except for A. quinquelobatus Garth and Kim, 1983 , from the Philippines. Actaeodes quinquelobatus was described as a close congener of A. consobrinus , differentiating in having five anterolateral teeth instead of four.

Distribution. Western Pacific from Japan to Australia through the Micronesian islands, and the western Indian Ocean. In Japan, this species is rather rarely found in the Ryukyu Islands, but seems to be not uncommon in the Ogasawara Islands based on the previous records and the specimens examined during the present study.