Berthellina delicata (Pease, 1861) species complex

(Figures 2 B–D)

Material examined. Twelve specimens. MB28-005057, ZWH, 5 Dec. 2011, 16m, 40mm; MB28-005058, ZRP, 0 7 Jun. 2012, 2m, 30mm; MB28-00 5059, ZRP, 0 7 Jun. 2012, 1m, 28mm; MB28-005060, ZRP, 0 7 Jun. 2012, 2m, 30mm; MB28-005061, ZRP, 26 May 2013, 1m, 30mm; MB28-005062, ZAR, 35m, 20mm; MHN-YT1013, VIS3, 12 Nov. 2013, 5m, 18mm; MB28-005063, VIS3, 12 Nov. 2013, 5m, 14mm; MB28-005 0 64, POA, 0 8 May 2014, 41m, 18mm; MB28-005065, NCh6, 0 5 Jun. 2014, 3m, 21mm; ZMBN105155, 21 May 2015, VIAIR, 2spcs., 4m, 12–26mm.

Habitats. Subtropical tidal reefs, rocky reefs and tropical coral reefs and bommies.

Occurrences. Ponta do Ouro, Zavora, Nuarro and Vamizi Island.

Geographic distribution. Indo-west, central Pacific. Hawaii, Midway Atoll (Gosliner et al. 2008), Japan (Baba 1949), Papua New Guinea, Seychelles, Réunion Island (Gosliner et al. 2008) and Mozambique (Martens 1879).

Remarks. Three-colour morphotypes were found: yellowish with a delicate reticulated pattern on the dorsum (Fig. 2 B); a translucent yellow body with low yellow tubercles (Fig. 2 C); and an orange body with white specks (Fig. 2 D). The variety of habitats, depths and specimen colours suggest that the animals collected here probably represent a complex of species. The systematics of Berthellina from the Indo-Pacific are in need of a comprehensive review (Cervera et al. 1999; Moustafa et al. 2016), because this taxon is indistinguishable by external characteristics alone (Gardiner 1936; Gosliner et al. 2008; Alvim & Pimenta 2015).