Phyllidia ocellata Cuvier, 1804

Papu, Adelfia, Bogdanov, AleXander, Bara, Robert, Kehraus, Stefan, König, Gabriele M., YonoW, Nathalie & Wägele, Heike, 2022, Phyllidiidae (Nudibranchia, Heterobranchia, Gastropoda): an integrative taxonomic approach including chemical analyses, Organisms Diversity & Evolution (New York, N. Y.) 22 (3), pp. 585-629 : 599-600

Phyllidia ocellata Cuvier, 1804

Twenty-seven specimens of P. ocellata were collected from North Sulawesi. Phyllidia ocellata is considered a very variable group with many colour morphs ( Brunckhorst, 1993; Gosliner et al., 2018; Pruvot-Fol, 1957; Yonow, 1996), and it differs from P. babai in having an orange ground colour while P. babai has a white dorsum. Phyllidia ocellata specimens have a yellow (or orange) background and large white tubercles, the lateral ones placed in the centre of black rings which are ocellated with a white line on both sides of the black ring (Fig. 5.5a–f). One of these black rings with a white tubercle is located anteriorly in front of the rhinophores, and there are two or three pairs present on each side of the midline. The foot and oral tentacles are grey, the latter with yellow tips. One specimen (Phma16Sa1, Fig. 5.5g) was first assigned to P. madangensis Brunckhorst, 1993 based on the overall black colouration with rounded white and yellow tubercles arising from a black background ( Undap et al., 2019: fig. 5E); however, our phylogenetic study clearly places this specimen within the clade of P. ocellata composed of another 30 P. ocellata sequences, and which is supported by a bootstrap value of 100. All four species delimitation tests resulted in a single species referable to P. ocellata ( Fig. S1 ), with an intraspecific variability of approximately 5% and up to 10% when including the long branch leading to PhocSa6 (Table S4).

Previous chemical investigations of P. ocellata reported isolation of bicyclic sesquiterpene isonitriles ( Fusetani et al., 1992; Okino et al., 1996). More recently, bicyclic and tricyclic sesquiterpene isonitriles and isothiocyanate were isolated from Australian P. ocellata specimens ( White et al., 2015). In the crude extract of a P. ocellata specimen analysed in this study (Phoc16Sa7, Fig. 5.5e), several minor peaks could be assigned to sesquiterpene isonitriles, which is in accordance with published reports. Polar brominated compounds were also detected, but these differ from those detected in P. cf. babai (see above). A derivative of the commonly occurring 5-bromotryptophane, 5-bromoabrine (m/z 297.000 and 298.996 [M + H] +) was detected only in P. ocellata .

Figures

Fig. 1 Sampling locations in Sulawesi, Indonesia