Pan sole

Geographical Origin and Habitat: Native to the fresh and brackish waters of South and Southeast Asia, including India, Bangladesh, Myanmar, and Thailand. It inhabits estuaries, river deltas, and slow-moving channels with muddy or sandy bottoms.

Taxonomy and Morphology: Belongs to the family Soleidae, genus Brachirus. Features a highly flattened, asymmetrical body with both eyes located on the right side of the head. The dorsal and anal fins are confluent with the caudal fin.

Social Behavior: Peaceful, shy, and benthic. It spends most of the daytime buried in the sand with only its eyes exposed, waiting to ambush prey and avoiding predators.

Coloration and Sexual Dimorphism: Highly cryptic mottled brown or grey dorsal coloration that mimics sand or silt. The blind side (underside) is pale white. There is no visible sexual dimorphism.

Aquarium Setup: Requires a tank of at least 30 gallons (100-120 liters) with a large footprint. The substrate must consist of fine, smooth sand (at least 3-5 cm deep) to allow burrowing without scraping its delicate skin.

Diet and Feeding: Hard to feed micro-predator. Rarely accepts dry foods. Offer live or frozen foods placed on the bottom: bloodworms, tubifex, brine shrimp, and small worms. Feeding should be done at night or after lights out.

Water Quality: Prefers slightly brackish water but adapts well to hard freshwater. Target parameters: pH 7.2-8.0, moderate to high hardness (GH 10-20), temperature 22-26°C (72-79°F). Gentle water movement is preferred.

Compatibility and Cohabitation: Extremely peaceful. Avoid housing with aggressive bottom dwellers or fast feeders that will outcompete it for food (such as large catfish or loaches). Suitable with peaceful midwater fish.

Aquarium Breeding: Not successfully bred in aquaria.

Risks and Diseases: Highly susceptible to skin infections and ulcers if kept on coarse gravel. Starvation is a common risk due to its slow feeding habits and cryptic lifestyle.