Phyllidia elegans Bergh, 1869
Phyllidia elegans Bergh, 1869: 439-455, 506-508, pls. 18B, 19; Fahrner & Beck, 2000: 199, 202, pl. 3 figs 7, 8; Domínguez et al., 2007: 93, figs 1B-C, 3; Gosliner et al., 2008: 285.
Phyllidiella sp. Gosliner et al., 2008: 295.
Non-Indonesian material.— RMNH.MOL.129995, Phantom Channel, Orpheus Island, GBR, Australia, 8 m depth, 6.xi.1986, leg. & photo R. Cattaneo-Vietti, 35 × 15 mm pres. (RC-V#02); RMNH.MOL.129994, Wheeler Reef, GBR, Australia, 10 m depth, 17.xi.1986, leg. & photo R. Cattaneo-Vietti, 33 × 13 mm pres. (RC-V#34) (included in Brunckhorst 1993: 33); WAM 216-88, Long Reef, Kimberly, Western Australia, vii.1988, leg. & photo C. Bryce; WAM 216-84, NE of North Lagoon, Scott Reef, Western Australia, ix.1984, leg. & photo C. Bryce; WAM 2420-84, W side of North Lagoon, Scott Reef, Western Australia, leg. & photo C. Bryce; WAM 2422-84 southern reef flat, Seringapatam, Western Australia, leg. & photo C. Bryce; NHMUK presented by W.E. Barnett 1957, CSIRO, Cronulla, NSW, Australia, 1957, leg. Miss B. Dews, one specimen 43 × 17 mm pres.; WAM 605-86, Christmas Island, eastern Indian Ocean, leg. F. Wells, photo C. Bryce; Mactan Island, off Cebu City, Cebu, Philippines, 1983, photo of two individuals, B.E. Picton (BEP PH/41 and BEP PH/66, specimens in Australian Museum, Sydney?).
Fig. 16. Phyllidia elegans. a, ventral surface of 33 mm specimen (RC-V#34), photo R. Cattaneo-Vietti; b, head and oral tentacles of same.
Description.— Both GBR specimens are typical elegans, with a large elongated oval body. The central region is separated by a black line meeting at an acute angle behind the anus and in an X-shape around and in front of the rhinophores, crossed by a transverse black line behind the rhinophores. Within this central area are three rows of orange-tipped tubercles, with faint black lines between them. The anus is located on the last midline tubercle within the black oval. Outside the black oval, the individual tubercles are scattered around the marginal band: this area is subdivided by 7-10 black lines extending to the margin at right angles, interspersed with short black lines, spots, and flecks (pl. 7 fig. 3). The other specimens vary slightly in having more black pigmentation. Ventrally the foot sole is pale, angular anteriorly and pointed posteriorly, with a dense black line along the midline (fig. 16a). The head and triangular oral tentacles are large (fig. 16b).
Remarks.— This species is well known from the western Pacific and eastern Indian oceans, and is relatively common. There are no records from the western Indian Ocean: Eliot (1906b) recorded P. elegans from the Maldives but the description is more applicable to P. alyta Yonow, 1994. A similar species, Phyllidia multifaria Yonow, 1986, exists in the Red Sea: this species has been synonymised with P. elegans by some authors (e.g. Brunckhorst, 1983) and not by others (e.g. Domínguez et al., 2007); the discontinuous distribution indicates that the two are probably different species, but certainly closely related.