Brazilian Frillfin

Bathygobius brasiliensis

The Brazilian Frillfin is a small reef fish native to the southwest Atlantic, specifically around Brazil. It can be identified by its maximum length of 8.1 cm and distinctive fin structures. The dorsal fin has seven spines and nine soft rays, while the anal fin has one spine and eight soft rays. This species often displays small pearly dots across its body, head, and fins, arranged in horizontal series on the body and vertical and horizontal series on the fins. Males have a somewhat rectangular first dorsal fin, while females and juveniles have a triangular shape. The Brazilian Frillfin inhabits shallow waters, typically between 1 and 3 meters deep, and is commonly found in reef crests and tide pools. It can be seen in solitary, in pairs, or in groups of up to 20 individuals. This fish feeds primarily on small invertebrates and occasionally on small fish. During the breeding season, territorial males guard the eggs, exhibiting aggressive behavior to protect their territory. Divers might encounter the Brazilian Frillfin in areas with rough waters or on sheltered sandy bottoms. Observing their interactions with other small fish species, such as blennies and labrids, can provide insights into their behavior. The Brazilian Frillfin is currently listed as Endangered on the IUCN Red List, emphasizing the importance of conservation efforts in its native habitats.