Jewelled blenny

Salarias fasciatus is a small (10–14 cm) herbivorous marine blenny (family Blenniidae) widely distributed in the Indo-Pacific, from the Red Sea and East Africa to Samoa and the Great Barrier Reef. It has a characteristically blenny-like appearance: an elongated, slightly compressed body, a blunt head with a steep forehead, large eyes set high on the head, a single long dorsal fin, and fleshy cirri (tentacles) above the eyes and on the nape. The mouth is underslung with a row of fine, comb-like teeth adapted for scraping algae from hard surfaces. Coloration is mottled brown, olive, and cream with irregular dark bars and pale spots, providing excellent camouflage on reef rubble. Males are typically larger and more brightly marked, with subtle blue spots and a more developed head crest. S. fasciatus inhabits shallow coral reef flats, lagoons, and rubble zones, where it is a territorial grazer constantly feeding on benthic filamentous algae, diatoms, and detritus—earning it the aquarium nickname "lawnmower blenny." It plays an important ecological role in controlling algal growth on reefs. Reproduction involves demersal eggs laid in crevices and guarded by the male. In the marine aquarium hobby, it is popular for algae control in reef tanks. The species is common and not threatened.