Care
The well-camouflaged and industrious little Dusky Jawfish is known from rocky and sandy substrates and the eroding edges of weed beds. This fish makes for a fascinating addition to mature reef aquaria, providing that one or two key requirements are met. These hard-working bottom dwellers need a mixed substrate that is at least 10cm (3.9") deep. Ideally, this will be comprised of 75% coral sand, and 25% small pieces of reef rubble (varying from approx. 0.5cm to 1.5cm in diameter). This will allow to the fish to construct a burrow, in which it will spend much time resting just inside the entrance, seemingly watching the world go by and waiting for food morsels to drift past overhead. At other times it will be busy rearranging things in and around its little tunnel, which can be very entertaining to observe. At night they sometimes close the entrance of the burrow with a larger pebble as they reverse in. The aquarium must have a tight-fitting cover, as these fish will jump, and lighting should always be turned on gradually so as not to startle your fish. Their constant excavation and digging means that powerful filtration and water movement is prerequisites. Dusky Jawfish may be kept in small groups; in fact, they often do better this way but do ensure that there is adequate space for them all to construct their homes (in the wild they may live as close as 30cm to one another). Ideally, all will be introduced at the same time to eliminate any territorial issues. Tankmates should be small and docile. The coloration and mottled pattern of these fish is highly variable and they are capable of a degree of colour change to blend in with their surroundings.
Feeding
Offer a varied diet of small meaty frozen foods such as Mysis, vitamin-enriched brineshrimp, plankton, and fine chopped krill/prawn/cockle/mussel. It may be helpful to feed the jawfish with a turkey baster, squirting some of the food above their burrows.
Breeding
Successful breeding reports are few and far between. Courting and spawning is said to occur at dusk or dawn. Dusky Jawfish are paternal mouthbrooders, meaning that the male fish incubates the eggs. These should hatch within 7-10 days. A ready supply of tiny planktonic foodstuffs will be required. Amazingly, young fish start digging their tiny burrows at just 3-4 weeks of age.
