Forktail Blenny FB092101
Meiacanthus atrodorsalis
Reef Compatible: Yes
Care Level: Intermediate
Disposition: Semi-aggressive
Min. Tank Size: 24 gallons
Mature Size: 4.5 inches
The Forktail Blenny is a striking reef fish known for its distinctive forked tail and sleek dark coloring. This active swimmer brings dynamic movement to established aquariums, darting between rockwork and coral formations. With an intermediate care level, it thrives in well-structured reef environments with plenty of hiding spots and established rock arrangements.
This specimen grows to approximately 4.5 inches at maturity and requires a minimum 24-gallon tank. While semi-aggressive in temperament, the Forktail Blenny is generally reef-safe and compatible with most coral species when proper tank conditions are maintained.
| Specification | Detail |
|---|---|
| Species | Meiacanthus atrodorsalis |
| Size (approx.) | 2 inches (newly acquired) |
| Mature Size | 4.5 inches |
| Minimum Tank Size | 24 gallons |
| Reef Compatibility | Yes |
| Aggression Level | Semi-aggressive |
FAQ
Is the Forktail Blenny safe with corals?
Yes, the Forktail Blenny is generally reef-safe and compatible with most coral species when the tank has established rockwork and proper hiding spots.
What is the expected growth size of this blenny?
The Forktail Blenny grows to approximately 4.5 inches at maturity.
What tank size is required for this fish?
A minimum tank size of 24 gallons is recommended.

Neil Hart –
Bought this blenny for my 30-gallon reef tank. It’s active and adds a lot of movement. The tail is very distinctive and it seems to be getting used to the setup. I’ve had it for three months and it’s still healthy and not showing any aggression toward my corals.
Isaac McGrath –
The fish arrived quickly and looks exactly as described. It’s been in my tank for two months now and is active but not overly aggressive. I do have a few small anemones, and it hasn’t touched them. Good choice for a reef tank with some structure.
Mary Lyman –
Great addition to my reef aquarium. The color and movement are impressive. I made sure to have plenty of rock cover, and it’s been staying in the middle of the tank without any issues. Very satisfied with the purchase.