Species description

Care, breeding and tankmates

Fish profile

Temperament

Peaceful

They exhibit a charming, peaceful, and highly inquisitive temperament. They are known for their habit of resting on a rock with just their heads poking out of a hole, watching the room. They quickly grow accustomed to their keepers and are quite bold during feeding time.

Diet

Herbivore

It is predominantly an herbivorous grazer that relies heavily on microalgae films present on live rock. Their diet should be supplemented daily with marine algae, spirulina flakes, and specialized herbivore preparations. Occasional small meaty offerings like cyclops or brine shrimp are usually accepted but should not be the staple.

Sex ratio

Solitary

Keeping a single specimen is recommended for most setups to avoid conspecific aggression. In larger aquariums, a mated pair may successfully cohabitate and potentially spawn. Avoid housing two males together, as they will aggressively defend their chosen rock formations.

Feeding frequency

Twice daily

They graze continuously throughout the daylight hours. Supplemental feeding should be offered one to two times daily to ensure adequate nutrition. Providing a constant supply of dried nori on a veggie clip is highly beneficial.

Bioload

Allen's blenny produces a very minimal bioload due to its small adult size. It has a negligible impact on water chemistry in an established aquarium. Standard reef filtration systems easily manage the modest waste this fish produces.

Flow

Strong

A moderate flow rate is preferred to encourage healthy algae growth and provide adequate oxygenation. They naturally inhabit areas with gentle surge and will perch in areas facing the current. If the flow is too extreme, they will spend excess time hiding in the rockwork.

Jump risk

Yes

Like many small, elongated fish, they have a tendency to jump when frightened or chased. A secure cover or tight-fitting mesh screen is mandatory to prevent them from landing on the floor. Pay special attention to small gaps near the back of the canopy.

Reproduction

Oviparous

They are cave spawners, with males attracting females to small crevices where the eggs are deposited and guarded. The male takes sole responsibility for aerating and protecting the clutch until hatching. While spawning behavior is sometimes observed, rearing the tiny larvae requires dedicated rotifer cultures.

Compatibility & tankmates

Reef safe

This is a model citizen in a reef aquarium, completely ignoring corals, anemones, and most invertebrates. It interacts peacefully with almost all other tank mates. However, territorial clashes can occur if housed with other species of bottom-dwelling blennies.

Tank level

Bottom

Allen's blenny is strictly a benthic species that spends its life on the live rock and substrate. They lack a functional swim bladder, causing them to rest on the rocks rather than hover. They require intricate rockwork with numerous small holes to serve as safe havens.