Convict Blenny

Geographical Origin and Habitat: Western Central Pacific: Philippines and Indonesia to the Solomon Islands. Inhabits shallow lagoons and sandy reef flats, living in extensive self-dug tunnel networks.

Taxonomy and Morphology: The only commonly kept species of the Pholidichthyidae family (not a true blenny). Eel-like, scaleless body. Reaches up to 34.0 cm in length.

Social Behavior: Peaceful and industrious. Adults spend almost their entire lives in underground tunnels, moving sand and pebbles with their mouths. Juveniles form dense schools.

Coloration and Sexual Dimorphism: Juveniles have horizontal black and white stripes. Adults develop irregular vertical black and white bands. No external sexual dimorphism.

Aquarium Setup: Requires a tank of at least 250 liters with a deep sand bed (at least 8-10 cm). Rockwork must rest directly on the glass bottom to prevent collapse due to digging. Secure lid is mandatory.

Diet and Feeding: Carnivorous. Feeds on zooplankton and small benthic organisms. In aquaria, accepts mysis, artemia, chopped seafood, and sinking pellets. Feed twice daily.

Water Quality: Maintain stable marine parameters: temperature 24-28 °C, pH 8.1-8.4, salinity SG 1.020-1.025. Requires efficient protein skimming.

Compatibility and Cohabitation: Peaceful with all tankmates. May bury corals or clams placed on the sand bed. Do not house with highly aggressive species.

Aquarium Breeding: Spawns deep inside the burrow. Parents care for the eggs and young. Captive breeding is documented.

Risks and Diseases: Skin abrasions from sharp rocks can occur. Known to jump, especially at night when startled.