Cobia

Adult cobia. Used with the permission of the artist, Duane Raver.
Used with the permission of the artist, Duane Raver

Occurrence and Description

Cobia, Rachycentron canadum, are found worldwide in temperature and tropical waters, with the exception of the eastern and central Pacific. Although considered a coastal migratory pelagic species, cobia inhabit both coastal and continental shelf waters. Cobia occur seasonally (spring – fall) in the northern Gulf of Mexico, however recent research indicates that some members of the population over-winter in the region.

Cobia are rapid growers that attain a size well over 100 pounds, and they are highly sought in local and adjacent Gulf waters for sport and as a premiere food fish. The current Mississippi state record cobia caught on conventional fishing tackle is 106 pounds, 13 ounces, and the current fly fishing tackle state record is 41 pounds, 13.6 ounces. Cobia is officially designated a saltwater game fish in Mississippi, a status which prohibits the sale of cobia caught in Mississippi territorial waters or landed in Mississippi.

Adult Cobia. Photo by Donald L. Hammond.
Adult Cobia. Photo by Donald L. Hammond.

The cobia is the only member of the family Rachcentridae. The family name is derived from the Greek words rhachis meaning spines and kentron meaning sting, a reference to the short, thick and very sharp isolated spines (usually eight) located in front of an elongate second dorsal fin. Cobia have a fusiform (streamlined) body and a broad, flattened head and typically are dark brown dorsally, paler brown laterally and white ventrally. 

Juvenile Cobia. Photo by Donald L. Hammond.
Juvenile Cobia, approimately six months old.
Photo by Donald L. Hammond.


A black lateral band as wide as the eye extends from the snout to base of the caudal fin or tail. This band is brilliantly displayed in juveniles, but tends to be obscured in adults. The large caudal fin is forked and slightly lunate in adults, though less so in juveniles.  The scales are small and embedded in very thick skin.


Biological Research

For the past 25 years, the University of Southern Mississippi Gulf Coast Research Laboratory fisheries scientists have conducted studies on various life history aspects of cobia, including age, reproduction, feeding ecology and seasonal movements. The studies are funded primarily by the Mississippi Department of Marine Resources, through the U.S. Fish and Wildlife Service's Sport Fish Restoration Program.

Life Cycle & Reproduction

Research reveals that the typical life span for male and female cobia is 9 and 11 years, respectively. Female cobia attain sexual maturity by age two or three and males by age two. Cobia spawn during spring and summer in offshore waters of the northern Gulf, with peak spawning during May -July. Females are ‘batch spawners’, releasing several hundred thousand eggs during each of several spawning events per spawning season. When fertilized, the buoyant eggs become part of the plankton and hatch within 24-30 hours, giving rise to rapidly growing larvae.

Cobia associate with turtles and rays and are drawn to structures such as buoys, petroleum platforms, and flotsam. Juveniles and adults are often found among pelagic Sargassum weedlines and mats where they feed and seek shelter from predators. Examinations of stomach contents reveal cobia to be opportunistic feeders, yet exhibiting a preference for crabs, squid and various fishes.

Tag-Release Program

GCRL’s Angler Cooperative Cobia Tag and Release Program is an extremely popular and effective science-based approach to understanding cobia growth, seasonal movements, and migratory patterns in southeastern U.S. marine waters. Volunteer angler participants from Gulf and south Atlantic states have contributed to the tag-release of more than 17,000 cobia since the program’s inception in the late 1980s.  

An adult cobia has been tagged (on left side of dorsal fin) and will be released.
GCRL file photo

The recapture of more than 1,000 tagged cobia offers extraordinary insight into cobia behavior, providing strong evidence of an annual spring migration from south Florida wintering grounds northward along both coasts of the Florida peninsula to spring-summer feeding and spawning grounds in northern Gulf and U.S. south Atlantic waters, with a return migration to south Florida in late fall. Several cobia tagged off Mississippi were recaptured as far west as Texas, while others were recaptured as far away as South Carolina and Virginia. Use of satellite tags attached to cobia is providing GCRL researchers and colleagues detailed information on long-range movements and habitat preferences throughout their migratory range.

Graphic of the general pattern of cobia migration in the southeastern U.S.
Source: GCRL


Aquaculture

GCRL pioneered the captive spawning of cobia in the U.S. in 1996. Emerging technologies for larval rearing and grow-out developed by several institutions, as well as the cobia’s rapid growth and high quality of flesh, position cobia as potentially one of the world’s most important marine fish for aquaculture production

Juvenile cobia in GCRL culture tanks
Juvenile cobia in GCRL culture tanks
Juvenile cobia in GCRL culture tanks
Juvenile cobia in GCRL culture tanks

Much is yet to be learned about cobia in Gulf waters, but GCRL cobia research provides vital scientific information to fishery resource managers and decision-makers. GCRL cobia researchers also take great interest in sharing the results of their work with anglers and a widely interested public.

Resources and References

A group of cobia following a whale shark.
A large school of cobia, Rachycentron canadum,accompany an 8.5-meter whale shark. The photo was taken from a petroleum platform in the northern Gulf of Mexico south of Louisiana. Photo provided by Fred Anderson.

 


Cobia Photos and Videos

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