Black Widow Sailfin Blenny – Size M (2″ to 2.5″)
Atrosalarias fuscus
Reef Compatible: Yes
Care Level: Intermediate
Disposition: Peaceful
Min. Tank Size: 24 gallons
Mature Size: 4 inches
| Specification | Detail |
|---|---|
| Species | Atrosalarias fuscus |
| Size (Adult) | 4 inches |
| Size (Available) | 2″ to 2.5″ |
| Reef Compatibility | Yes |
| Difficulty Level | Intermediate |
| Behavior | Peaceful |
| Minimum Tank Size | 24 gallons |
FAQ
Is the Black Widow Sailfin Blenny safe to keep with corals?
Yes, this blenny is reef compatible and generally does not harm corals.
What is the expected mature size of this blenny?
The mature size is approximately 4 inches.
What tank size is required to keep this blenny?
A minimum tank size of 24 gallons is recommended.

Megan Hill –
The blenny is active and peaceful in my 30-gallon tank. It doesn’t bother the corals and stays near the rocks. Easy to spot and maintain. Good for intermediate reef keepers.
David Johnston –
Arrived quickly and looks healthy. It’s been a week and still active. No aggression, just explores the tank. Works well with my anemones and soft corals.
Dylan Smith –
Perfect addition to my reef setup. It’s small but lively and doesn’t stress the other fish. I appreciate the clear labeling and accurate size description.