Black Sailfin Blenny (Atrosalarias Fuscus)

Also Known As: Brown Coral Blenny, Highfin Blenny

Compatibility and Behavior
The Black Sailfin Blenny (Atrosalarias fuscus) is a reef workhorse with a bit of flair. The deep chocolate to jet-black body is dusted with subtle speckles, and it carries a tall, sail-like dorsal fin it raises when grazing or posturing, which, along with the blunt head, big eyes, and constant "kissing" motion as it scrapes algae off the rock, gives it a lot of personality. It's a dedicated herbivore, spending its day combing rock faces and crevices for filamentous algae, diatoms, and trapped detritus, which makes it a genuine ally against nuisance growth on the hardscape. It's generally reef safe with corals and most inverts, though an individual may occasionally nip near clam mantles or SPS if natural algae runs scarce, so use some caution in a very clean, SPS-heavy system. Like the other grazing blennies, it can get territorial toward other algae-grazing blennies or similarly shaped herbivores it sees as competition, so keep it as the only herbivorous blenny in the tank unless the system is large and heavily rock-scaped.

Aquarium Requirements
As with all the grazing blennies, the number-one requirement is a tank that grows algae. It does best in an established system around 30 gallons or larger with abundant mature live rock and natural microalgae, far better suited to a tank that's been running several months or longer than a brand-new setup, since without enough algae it can gradually lose weight and condition. Aquascape with multiple ledges, caves, and scattered rock islands so this bottom-oriented fish can perch, hide, and rotate through grazing routes. A tight-fitting lid or mesh screen is strongly recommended, since like other blennies it can jump when startled or chased. Moderate flow that keeps surfaces oxygenated and moves detritus into filtration, plus stable reef-quality water, supports both the blenny and the algae it lives on. Supplement its grazing with nori, spirulina-based flakes and pellets, and algae wafers, plus the occasional small meaty food like mysis or brine for variety.

Specifications
Approximate Size: 2–3"
Diet: Herbivore; primarily filamentous and film algae, detritus, and microfauna, supplemented with nori, spirulina-based flakes and pellets, algae wafers, and occasional small meaty foods such as mysis or brine
Origin: Indo-West Pacific
Care Level: Moderate
Reef Safe: Yes
Temperament: Peaceful
Minimum Tank Size: 30 gallons
Special Considerations: Depends heavily on natural algae, so it needs a well-established tank with abundant growth or heavy supplemental vegetable feeding to hold condition; can be territorial toward other herbivorous blennies or similar grazers, so best kept as the only herbivorous blenny; a jumper, so a tight-fitting lid is recommended