Also called the Moustache Jawfish. The Black Cap Jawfish are interesting animals with an amusing defense mechanism. When threatened, jawfish will open their mouths to comical proportions in an attempt to intimidate. Provide a loose substrate as the Black Cap Jawfish constructs a burrow to use as its home. This fish can be high strung until they settle into an aquarium. Not aggressive, but will defend its burrow. Diet should include mysis and brine shrimp, as well as other small chopped frozen seafoods. Other related Gobies include: Clown Goby - Citron, Clown Goby - Green, Clown Goby - Yellow, Coral Catfish, Firefish Goby - Helfrichi, Firefish Goby - Purple, Firefish Goby, Golden Head Sleeper Goby, Green Mandarin Goby, Black Cap Jawfish, Orange Spot Goby, Rainfordi Goby, Scissortail Dartfish, Sleeper Banded Goby, Sleeper Goby - White, Tomiyama Shrimp Goby, Twinspot Goby, Watchman Goby - Banded, Watchman Goby - Blue Spotted, Watchman Goby - Spotted, Watchman Goby - Tiger, Watchman Goby - Wheeler's, Watchman Goby - Yellow, Yashia White Ray Shrimp Goby, Yellow Target Mandarin Goby, Zebra Barred Dartfish Maximum Length: 5 in. Care Level: Easy Family: Opistognathidae Reef Compatibility: Reef Safe Minimum Aquarium Size: 30 gal. Range: Indo-Pacific: Red Sea, Ryukyu Islands, Great Barrier Reef, Marshall Islands in Micronesia. Water Conditions: 74-80° F; sg 1.020-1.025; pH 8.1-8.4