Adults inhabit rivers, creeks and billabongs, usually in quiet or slow-flowing water among vegetation, around log debris or beneath undercut banks.
It feeds on insects, fishes and crustaceans and spawns between October and February. The male guards the nest, which is located on a solid surface, frequently on the ceiling of a rock crevice or on a submerged log. Each nest contains up to 70,000 eggs. The incubation period lasts between 5-7 days.
It is a fish with a remarkable colour range – from yellow through beige to black. The yellow fish variation in Sleepy Cod is rare, but is thought to have particular marketing qualities for Asian restaurants – where live fish are held in tanks for personal selection by patrons, who then pay high prices.
Comments from Ausyfish hatchery website (www.ausyfish.com ):
One of the most promising fish for future aquaculture and aquaponics is Sleepy Cod This fish has many qualities to give it all-round appeal as aquaculture species for the future.
- It has been argued that this species has the best eating quality of all Australian freshwater fish.
- Extremely easy to transport at high densities.
- High flesh recovery.
- Can be kept and grown in high densities.
- Never have muddy flavour. Early indications are that it will be unsuitable for pond grow-out situations, however will probably be ideal for growing in recirculating systems, such as aquaponics.
There are a few smaller growers who have already tried these fish for themselves with positive result. These growers have not had the benefit of having a blueprint to follow. In Asia there already exists a fish very similar to Australia’s Sleepy Cod. It is known as the marbled or sand goby (Oxyeleotris marmoratus). Asian sleepy cod are grown throughout South East Asia, particularly in Malaysia, Thailand and Vietnam. They are the highest-priced freshwater fish in Asia, with farm gate prices of over AU$30/kg in Taiwan. Retail prices in Malaysia and Thailand are around AU$45 per kg. This fish fetches some of the highest prices, (around four times that of Silver perch) and is regarded as top quality. There is no doubt an overseas market is out there just waiting for someone to meet.
Shipping live, market sized Sleepy Cod, should prove to be relatively unchallenging. They do seem to live up to their name, “sleepy” and lay motionless in shipping bags.
This means their use of oxygen is minimal and therefore production of CO2 low. Many large fish should be able to be packed in an absolute minimum amount of water.
Source: Aquaponics Network Australia newsletter