🐠 Black Sailfin Blenny (Atrosalarias fuscus)
Marine Reef-Safe Algae Grazer • Solid Black High-Fin Display Fish • Voracious Microalgae Eater • Intermediate Reef Invertebrate
 
📋 The Black Sailfin Blenny (Atrosalarias fuscus), also known as the Highfin Blenny or Dusky Blenny, is a striking solid-black marine fish that stands out through contrast rather than pattern, especially set against lighter rock or sand.
Native to shallow reef flats, coral beds, and slopes across the Indo-Pacific, including Java, Fiji, the Maldives, and Vanuatu, this species spends its days grazing steadily across live rock, taking short hops between feeding spots.
Worth knowing before purchase: this species is close to an obligate microalgae eater, meaning it genuinely depends on established algae growth in the tank to thrive. Tanks without natural microalgae won't sustain it long-term without consistent supplemental feeding of algae-based foods. It's also a genuinely territorial species — best added as one of the last fish to the tank, kept singly unless housed as an established pair, and not combined with other blennies unless the tank is very large with ample hiding spots. Some individuals may nip at small polyp stony corals or clam mantles, so reef compatibility is generally good but not absolute.
With ample algae supply, established live rock, and thoughtful stocking, it thrives as a Distinctive High-Contrast Reef Grazer.
 
🖤 Highlights
⚫ Striking Solid Black Colouration: Stands out through contrast against rock and sand
🌿 Voracious Algae Grazer: Genuinely effective against nuisance hair and string algae
⚠️ Near-Obligate Microalgae Eater: Needs established algae growth or consistent supplemental feeding
🐟 Genuinely Territorial: Best added last, kept singly unless an established pair
🌊 Generally Reef Safe: Occasional LPS or clam mantle nipping possible