Calcinus imperialis Whitelegge, 1901
Illustrations. - • Male shield length 6.0 mm, Tuamotu. • Left third pereopod, coloration pattern. • Aspect of left chela, outer face.
References. - Calcinus imperialis Whitelegge, 1901: 48, pl. 9 (type locality: Lord Howe Island, Australia).
Calcinus imperialis. - Grant & McCulloch, 1907: 154 (Norfolk Island). - Chilton, 1911: 552 (Kermadec Islands, Meyer & Sunday Islands). - DiSalvo et al., 1988: 458 (Easter Island). - Morgan, 1991: 882, fig. 21–23 (Eastern Australia). - Tudge, 1995: 11, pl. 1, fig. 1f (Australia). - Poupin, 1997: 697, fig. 3f', 5c, 7d (Tuamotu, French Polynesia; Lord Howe Island, New Caledonia, Vanuatu). - Forest et al., 2000: 15 (Checklist). - Forest & McLaughlin, 2000: 79 (Kermadec). - Poupin et al., 2003: 94 (Easter Island). - Asakura, 2002: 64 (Norfolk and Lord Howe).
[Not Calcinus imperialis - Wooster, 1984: 130 (Mariana). - Poupin, 1996a: 14 (Tahiti, Society Islands, and Moruroa Tuamotu) = Calcinus isabellae Poupin, 1997].
Shield and cephalic appendages. - Ocular scale with a single terminal spine.
Chelipeds (P1). - Upper margin of right chela tuberculated or spinous. Outer face of left palm with 2–3 subcircular depressions.
Ambulatory legs (P2-P3). - Dactyl of P3 subequal to propodus or slightly shorter (0.7–0.9). Distal pilosity of P3 dense, forming a brush of setae.
Armament of telson. - Left lobe of telson with a single spine. Right lobe with a single spine (sometimes missing).
Coloration. - Shield green-olive (with blue spots). Ocular peduncle uniformly colored. Detailed coloration of ocular peduncle: green-olive. Distal antennular peduncle yellow-orange (basal segments and flagella yellow). Distal antennal peduncle yellow-orange (basal segments and flagellum yellow). Chela with red spot at base of dactyl (background color green-brown turning to white distally; carpus of cheliped green-olive; blue spots at tip of spines or tubercles). Ambulatory legs (P2 & P3) with ring(s) (green-olive, black, and pale yellow).
Habitat. - Facultative associates of corals (e.g. Pocillopora, Acropora), shallow-waters.
Geographic distribution. - Still known only from the South Pacific, between 14–34°S from eastern Australia to Easter Island including Vanuatu, New Caledonia, Norfolk Island, Kermadec Islands, and French Polynesia. The species has still not been found in the Indian Ocean nor in the North Pacific and its report from these areas by Forest & McLaughlin (2000: 79) is erroneous (J. Forest, personal communication). Indo-West Pacific.
