All About Cobia

COBIA FISH BITES Family and Etymology Cobia is the only species in the family Rachycentridae. Remoras (Family Echeneidae) are their closest relative. The scientific name for cobia is Rachycentron canadum, which is derived from two Greek words: rachis (vertebral column) and kentron (sharp point). This name refers to their 7-9 extremely sharp, retractable, dorsal spines.

Range Cobia is a pelagic fish which occurs worldwide in all tropical and temperate seas, except for the eastern Pacific Ocean. In the western Atlantic, cobia is found from Nova Scotia south to Argentina; in the eastern Atlantic from Morocco to South Africa; and in the western Pacific from Japan to Australia. Cobia prefer water temperatures between 20°C - 30°C; they migrate south to warmer waters during autumn and winter then journey back north when temperatures rise again in the spring.

Fishery Globally, there is no significant cobia fishery, this is because adults are often solitary or travel with just a few other individuals, frequently in the company of sharks. This makes them a difficult species to target and capture is therefore often incidental. Despite this, however, cobia is a highly sought after food fish throughout its range. In Mexico, for example, it is known as "esmedregal" and is the fish of choice for weddings and celebrations. In Belize, where it is known as "cabio", a captured cobia likely won't make it to market because the fisherman will keep it as a family treat. Cobia is also highly prized as a game fish. The Florida cobia record is 103lbs. 12 oz, but the world record, held by Australia since 1985 is 135lbs. 9oz (a 2 meter long fish!).

Cobia in Aquaculture Not only is cobia a very tasty fish, it also grows very quickly: they reach 6-7kg one year after hatching (three times the growth rate of Atlantic salmon). These characteristics make cobia an appealing aquaculture species. Farmed cobia have a low feed conversion ratio, another plus for an aquaculture species. Although commercial production of cobia has only just begun in the west, it already has a successful history in Asia, most notably in Taiwan where cobia is stocked in around 80% of ocean cages.

Cobia at ACFK ACFK first started working with cobia in 2002. Interest in cobia farming has grown steadily in the interim and each year we supply new customers in new countries. Particularly rewarding are new ventures which are employing out of work fishermen from areas where wild fish stocks have been decimated by overfishing. The pictures below give an insight into what goes into raising a cobia fingerling at ACFK.

First come the broodfish Cobia become sexually mature at 2 years old. Their natural spawning season is from April to September. When a female is close to spawning the males become extremely attentive because they only have a few seconds during which they can fertilize her eggs. Fertilized eggs are positively buoyant which means they are easy to collect from the surface of the tank.

Next come the eggs Fertilized cobia eggs have an average diameter of 1.3mm and an incubation period of approximately 30 hours at 26°C. Newly hatched larvae measure in excess of 3mm.

Then lots of food After three days the yolk sack is used up and it is vital to supply exogenous feeds. Over the next few weeks the larvae will be weaned onto successively larger sizes of zooplankton and finally onto dry feed. These zooplankton are rotifers, artemia and copepods (pictured left to right above).

And attention to detail The fast growing larvae need to be monitored closely: water in the larval rearing tanks is around 26°C, with ambient temperatures this high, water quality problems can accelerate rapidly if left unchecked.

And finally fingerlings The juveniles will have reached 1g in five to six weeks by which time they are ready to be shipped out to their nursery site.