Phyllidia coelestis Bergh, 1905

Yonow, Nathalie, Anderson, R. Charles & Buttress, Susan G., 2002, Opisthobranch molluscs from the Chagos Archipelago, Central Indian Ocean, Journal of Natural History 36 (7), pp. 831-882 : 862

Phyllidia coelestis Bergh, 1905

(®gure 16b)

Phyllidia coelestis Bergh, 1905: 182 , pl. 3, ®gure 16; Lin, 1983: 152, pl. 1, ®gure 3; Brunckhorst, 1989: 37, numerous ®gures; Brunckhorst, 1993: 30, pl. 1F, H.

Phyllidia nobilis: Farran, 1905: 345 , pl. 3, ®gures 16, 17.

Phyllidia elegans: Edmunds, 1972: 82 , ®gure 4B.

Phyllidia alia Yonow, 1984: 224 , ®gures 6C, D, 7A, 8F, G.

NOT Phyllidia picta Pruvot-Fol, 1957: 110 , ®gures 5±12 (as per Brunckhorst, 1993) (5 Fryeria picta ; see Yonow, 1996).

Material. Chag96/32: 12 mm; outer reef, Ile de la Passe, Salomon Atoll; 14 February 1996; at 15 m depth. Chag96/43a, b: 32 mm, 28 mm; inner reef, Ile Diamant, Peros Banhos Atoll; 19 February 1996; at 3 m depth. Chag96/46: 16 mm; outer reef, Ile Diamant, Peros Banhos Atoll; 20 February 1996; depth not recorded; no photographs taken. Chag96/53a, b: 25 mm, 22 mm; inner reef, Ile Mapou, Peros Banhos Atoll; 21 February 1996; at 9 m depth; no photographs taken. Chag96/67: 353 15 mm; coral bommie, east of Ile Poule, Peros Banhos Atoll; 25 February 1996; at 9 m depth; no photographs taken.

Description. Ground colour pale granular blue. Three longitudinal black stripes, one on the midline interrupted by yellow tubercles; the two laterals were continuous but did not meet anteriorly between the rhinophores. Variable number of rounded, yellow tubercles arranged longitudinally; fewest in smallest specimen but otherwise no obvious correlation with size. Small black ¯ecks peripherally. Rhinophores slightly deeper yellow than tubercles.

Geographic distribution. Indo-West Paci®c: Sri Lanka (Yonow, 1984 as P. alia ), the Seychelles (Edmunds, 1972 as P. elegans ) and South Africa ( Gosliner, 1987 as P. varicosa ) to Fiji ( Brunckhorst, 1993).

Remarks. Brunckhorst (1989, 1993) redescribed and illustrated this species; the majority of his material was from the Paci®c, where it also appears to be relatively common.