Grow-out of cobia

After reaching 20–30g, cobia juveniles can be stocked into grow-out ponds at 4000–7000 per hectare.

Stocking density impacts growth performance and needs to be managed throughout the growth cycle. Stocking into cages or compartments within ponds permits better control over health management, sorting, and harvesting.

Careful management of pond water quality through aeration and water exchange is necessary to accommodate the high levels of oxygen consumption and ammonia excretion of this species.

Growth performance is greater in tropical northern regions due to warmer water temperatures; however, exposure to extended periods of low salinity (< 8 ppt) can pose health risks. Overwintering under controlled conditions prior to pond stocking is advised for southern regions to mitigate suppressed feeding and immunity resulting from low water temperatures (<20^oC).

Annual production of 10–30 t/ha is achievable depending on geographic region.

Feeding

Cobia are voracious carnivores and readily accept manufactured diets in floating pelletised form. Pellet or kibble size varies with the size of the fish. Dietary formulations with elevated levels of taurine vastly improve growth performance and survival.

Cobia respond positively to feed ingredients used to enhance digestibility. Optimising feeding frequency particularly for harvestable-sized cobia (>2 kg) can be a practical strategy for reducing feed input without affecting growth performance. Food conversion ratios (FCR) range 1.5:1–2.5:1 depending on factors such as:

• feed composition
• fish age
• stocking density
• culture system.

Also consider…

• Read about grow-out of cobia in ponds or lakes (PDF, 3.5MB) in southern (PDF, 5.3MB) and northern (PDF, 2.6MB) Queensland.
• Read about grow-out performance of cobia with dietary taurine supplementation (PDF, 1.4MB).