Unusual colour patterns of territorial damselfishes (Pomacentridae: Stegastes) in the Southwestern Atlantic

Abstract

Reef fish usually display a remarkable variety of colours and coloration patterns. The colour patterns are largely used for species identification, and some morphologically conservative genera are highly dependent on coloration for this purpose. In this context, this paper aims to briefly describe unusual colour patterns recorded for territorial damselfish of the genus Stegastes in the south-western Atlantic Ocean. Four unreported coloration pattern types were observed in three species (S. fuscus, S. rocasensis and S. pictus). The pale morph which is characterized by individuals presenting whitish marks over the regular coloration pattern was recorded in S. fuscus in north-eastern reefs and S. rocasensis in Fernando de Noronha archipelago. On the other hand, S. fuscus and S. pictus presented other types of unusual coloration patterns, which are characterized by an irregular cover (blue or dusky) over the regular colour pattern. Another type of unusual coloration pattern was recorded for S. fuscus, which presented a yellowish/reddish dorso-anterior band. Additionally, two distinct colour patterns of adult S. variabilis, from the south-eastern and north-eastern Brazilian reefs are reported.