Comprehensive DescriptionRead full entry
The genus Emblemariopsis, with the allied Coralliozetus, includes a growing number of species (and species complexes) in the tropical western Atlantic, all of whom occupy small holes among corals and coral rock. These tiny "glass" blennies are typically transparent and quite inconspicuous, although territorial males are black-headed and, in most species, display a red banner or spike on their dorsal fins. The species are quite similar in appearance and females and juveniles can be almost indistinguishable. Most species have orbital cirri, but one clade does not. Larvae of Emblemariopsis are small blennioid larvae with few distinguishing characteristics, other than reduced procurrent caudal-fin rays (3 or 4, often only two apparent on larvae). Fin-ray counts are required for identification by eye: almost all of the species have fewer dorsal-fin soft rays, anal-fin rays, and (often) procurrent caudal-fin rays than other chaenopsids. The low counts in this group typically overlap the labrisomid blennies of Labrisomus and Malacoctenus, but larvae can be quickly distinguished by the reduced markings on Emblemariopsis larvae (only the ventral midline series), the few procurrent caudal-fin rays (3 or 4 vs. 6-10), and the smaller size at similar larval stages. There is some overlap in fin-ray counts among Caribbean Emblemariopsis; some species share counts with one or several congeners, but often the congeners do not have overlapping geographic ranges and the process of elimination can be diagnostic. Unfortunately, some species complexes are made up of cryptic species with differing fin-ray counts in various regions, making it necessary to know the precise locality and the potentially sympatric congeners to be sure of a species-level identification (in the absence of a DNA match). Unlike the Acanthemblemaria and Emblemaria, the regional species are not yet well worked out and ranges and species complexes are not resolved. The number of species of Emblemariopsis at one location apparently varies from one to five; the maximum number coexisting at one location is found (thus far) in PR and the USVI (5), Belize (4 or 5), and Venezuela (4 overall coastline); Florida has only one.