Species group: Jawfish
Other common names: Moustache Jawfish; Bluespotted Jawfish; Blue Spot Jawfish
Scientific name: Opistognathus rosenblatti
The Blue Dot Jawfish is a medium maintenance fish. It is a hardy fish and can breed in captivity. Blue Dot Jawfish use their big mouths like scoops; they constantly move sand, build new borrows, or dig to the bottom of the tank. This propensity to remodel their burrows sometimes causes them to raid a neighbor's burrow for choice pebbles and shells.They are bottom dwellers who hover above their den and dart back into it at the first sign of danger.
The Blue Dot Jawfish has an orange head. The oblong body is also orange with irregular-shaped blue spots scattered all over its body. The blue dots glow under aquarium lights. It has long continuous dorsal and anal fins like all Jawfishes. It has bug-like eyes and a bucket-like mouth. Its body is covered with cycloid scales but its head is devoid of scales, which makes it easy to burrow in sandy surfaces.
It is very aggressive towards members of its own species, so only a single Jawfish or a mated pair is ideal in each tank. These fishes may act semi-aggressively toward other fish. They are territorial of the area around their burrows. They defend their territory by opening their mouths very wide as a warning to other fish, and sometimes they even use their mouths to ‘joust’ with other Jawfish. Without an extensive view in all directions, they tend to become reclusive and swim closer to the den than usual or may only extend their head outside their den. This reclusive behavior also occurs when fast or active swimming fish like Surgeonfish, Angelfish, and Butterflies are present. Larger fishes that dart or become hyperactive during feeding may potentially cause problems. It is best that Jawfish are the first to be introduced to the tank. They should be housed with docile, passive tankmates or slow-moving fishes that are nearly equal or smaller in size.
The Blue Dot Jawfish must be kept in a tank of at least 20-30 gallons with plenty of places to hide and swim. It is a myth that strong lighting should be avoided; any aquarium lighting is sufficient. Jawfish typically dwell in burrows or dens that they construct in sandy substrate by stuffing their mouths with sand and spitting it out elsewhere, slowly creating a tunnel.
A 10- to 12-inch deep sandbed is preferred, with a minimum of 6 inches because the den of the Jawfish is typically 3 to 4 inches deep. There must also be an unlimited supply of rubble larger than 10 mm in width, like broken coral branches, pieces of coral limestone, and bivalve and snail shells. Jawfishes will use the rubble to build its den. Rubble must be replaced as and when it gets used. Snail shells are used as a roof, which the Jawfish pulls over the den entrance when it retires, and removes when it wakes up.
Jawfish normally keep only one den each, but they remodel it daily. The remodeling process is underground and is unseen, except for the occasional mouthful of sand that gets deposited alongside the burrow opening, traded for a piece of carefully chosen rubble. While housing the Jawfish it must be kept in mind that it prefers to have a 360° view of its surroundings.They are known to be jumpers and must be kept in an aquarium with a tight-fitting lid to prevent escape.
burrow, metallic blue spots, town building, fascinating specimen, intermediate aquarist
territorial issues, uncovered tanks, inverts
substrate, easier jawfish specimens, little constuction worker, sandy bottom tank