Cobia (Rachycentron canadum)

Also known as: Black kingfish
GenusRachycentron (1)
SizeLength: 110- 200 cm (2)
Weightup to 68 kg (2)

The Cobia has yet to be classified by the IUCN.

With a broad, depressed head, elongated body, and powerful tail fin, the cobia (Rachycentron canadum) is often mistaken for a shark, but it is actually a member of an order of fish known as perches (Perciformes) (3). This unusual, yet distinctive fish is also the sole member of the family Rachycentridae (4).

The cobia is dark brown, with a creamy underside and two silver or bronze lines streaking along its side (3) (4). It has a reduced first dorsal fin comprised of numerous small spines, and a more elongated second dorsal fin and anal fin, which both run half the length of the body (4). This carnivorous fish also has a large mouth armed with an array of small teeth, and a swollen lower-lip that protrudes past the upper-lip (5) (6).

The cobia is distributed in warm ocean waters worldwide, excluding the central and eastern Pacific Ocean (2).

Occurring in a range of marine environments, the cobia is found over coral reefs, off rocky shores, over mud, sand and gravel bottoms, around drifting or stationary objects such as rigs, and occasionally in estuaries (2) (3) (4). It is found at depths of up to 18 metres (3).

The cobia feeds mainly on crustaceans, especially shrimp, squid and crab, as well as small fish and eels (2) (3) (4) (5) (6).

In the western Atlantic, shoals of mature adult cobia spawn during the warmer months. During this event, the female cobia releases an extraordinarily large amount of eggs, and the male releases sperm for external fertilisation (2) (4). The fertilised eggs are dispersed by ocean currents, and the resulting larvae float passively in the ocean currents as part of the zooplankton community (2). Juvenile cobia hide amongst sea-grass to feed and shelter from predators (7).

With a worldwide distribution, the cobia does not appear to be under any immediate threat of extinction. It is, however, an important fish in aquaculture, particularly in China, Taiwan and the USA, where huge stocks of cobia are farmed in large tanks. Initially a vast number of individuals are taken out of the ocean to establish a captive population, but this population then creates all further generations for the industry, and so is self sufficient (7). The cobia is also a popular game fish due to its delicious taste and habit of swimming near to the surface around man-made structures and boats (2) (3) (4).

There are currently no known specific conservation plans targeting the cobia.

For more information on fish conservation:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. UNEP-WCMC (October, 2010)
  2. FishBase - Cobia (October, 2010)
  3. Schultz, K. (2010) Ken Schultz’s Essentials of Fishing: The Only Guide you Need to Catch Freshwater and Saltwater Fish. John Wiley & Sons Inc, New Jersey, USA.
  4. Van der Elst, R. (1993) A Guide to the Common Sea Fishes of Southern Africa. Struik Publishers, Cape Town, South Africa.
  5. McEachran, J.D. and Fechhelm, J.D. (2005) Fishes of the Gulf of Mexico: Volume 2. University of Texas Press, Texas, USA.
  6. Randall, J.E. (1995) Coastal Fishes of Oman. University of Hawaii Press, Hawaii, USA.
  7. Fisheries and Aquaculture Department (United Nations) - Cobia (October, 2010)