Breeding the Floral Blenny (Petroscirtes mitratus)

Petroscirtes mitratus is a small Indo-Pacific blenny that pairs to spawn and nests inside empty mollusk shells, laying demersal adhesive eggs guarded at the nest.

Overview

Petroscirtes mitratus (family Blenniidae), the floral blenny, is a small Indo-Pacific species reaching about 8.5 cm total length, found from the Red Sea and East Africa to the Samoan and Tongan islands at depths of 0-8 m. Adults occupy shallow protected lagoons and reef flats with algal and seagrass clumps and characteristically swim with the tail oriented vertically.

Sexing

FishBase records the species as oviparous with distinct pairing. There are no widely documented external sexing cues for the aquarium, so identifying a compatible male-female pair generally relies on observing pairing and nest-tending behavior.

Breeding Setup

Recreate the species' habitat with a quiet aquarium offering algae, seagrass-like cover and, importantly, empty mollusk shells, which this blenny uses for nesting in the wild. Stable shallow-reef tropical parameters from the linked species record support breeding condition.

Spawning Behavior & Trigger

The pair spawns inside a chosen cavity, with empty mollusk shells serving as the natural nest site according to FishBase. The female deposits eggs in the shell where the male fertilises and tends them, a behavior typical of nest-guarding blennies.

Egg & Fry Care

Eggs are demersal and adhesive, attached to the substrate by a filamentous adhesive pad or pedestal, and the larvae hatch as planktonic forms found in shallow coastal waters. Rearing these planktonic larvae requires a dedicated larval system and graded live foods.

Common Challenges

As with most marine blennies, the hardest part is rearing the tiny planktonic larvae through their early stages, which need correctly sized live prey and stable water quality. Providing suitable shell nests is essential to trigger and protect spawning.