Black Cap Jawfish

The Black Cap Jawfish, *Opistognathus randalli*, is a fascinating and charismatic addition to the Western Atlantic reef aquarium. This species is known for its distinctive black marking on the top of its head, contrasting with its generally pale body. Jawfish are renowned for their captivating behavior of constructing and maintaining burrows in the substrate, often using their large mouths to move sand and rubble.

A minimum tank size of 30 gallons is recommended for the Black Cap Jawfish, providing ample space for burrow construction and swimming. A deep sand bed (at least 3-4 inches) mixed with rubble is essential for them to create their homes. They are generally peaceful but can be territorial around their burrow, especially towards conspecifics or other burrowing species. They are considered to have an intermediate level of care, primarily due to the requirement for a suitable substrate and their need for a secure environment.

In the aquarium, the Black Cap Jawfish will readily accept a varied diet of small meaty foods such as mysis shrimp, enriched brine shrimp, and finely chopped seafood. They are ambush predators, often waiting at the entrance of their burrow to dart out and capture passing food. Providing multiple small feedings throughout the day is beneficial. They typically reach a maximum size of around 4 inches in captivity. While not commonly bred in home aquariums, they are known to be mouthbrooders in the wild.