Forktail Fang Blenny

Meiacanthus atrodorsalis

Also known as Yellowtail Fang Blenny, Eyelash Fang Blenny, Forktail Blenny

SaltwaterFish

Forktail Fang Blenny (Meiacanthus atrodorsalis) — Rickard Zerpe · CC BY 2.0

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 8.1–8.4
Adult size: 4.3 in (11 cm)
Minimum tank: 30 gal (114 L)
Temperament: Peaceful
Social behavior: Solitary
Swim level: Middle
Difficulty: Easy
Breeding: Hard
Rarity: Common
Reef safe: Reef safe
Origin: Western Pacific reefs, from Bali and the Philippines to Samoa
Family: Blenniidae

Overview

Peaceful toward other species and safe around corals, clams and most invertebrates, though it may pick at small ornamental shrimp or feather duster worms if underfed. It is best kept singly or as an established male-female pair, since two unrelated fish of the same or similar-looking species usually fight. Offer a varied diet of mysis and vitamin-enriched brine shrimp, finely chopped seafood and herbivore preparations several times a day; it will also graze on copepods and algae film in the rockwork.

In the wild

Native to shallow reef flats and lagoons across the western Pacific, from Bali and the Philippines east to Samoa. It shelters in abandoned worm holes and small crevices in the reef and, unusually for a blenny, spends much of its time swimming freely in open water instead of perching on rock. Keep it in at least 114 liters (30 gallons) with plenty of live rock offering tight hiding spots, and a well-sealed lid, since it jumps readily when startled.

Good to know

Meiacanthus fang blennies carry a pair of long, grooved canine fangs on the lower jaw that connect to venom glands, an oral venom system used purely for defense rather than for hunting prey. The venom contains opioid-like compounds and enzymes that can drop a predator's blood pressure and cause disorientation, giving the blenny time to escape. The bite is harmless to people beyond a sharp, localized sting, but several unrelated reef fish, including the bicolor fangblenny and bicolor blenny, have evolved to mimic its coloring and swimming style to borrow that protection.

Did you know

Its venomous bite is such an effective deterrent that at least two other reef fish, the bicolor fangblenny and the bicolor blenny, have evolved to look almost identical to it so predators leave them alone too, even though neither actually carries venom.