The blue catfish ( Ictalurus furcatus) is a large species of North American catfish, reaching a length of and a weight of .[
]
An omnivorous predator, it has been introduced in a number of reservoirs and rivers, notably the Santee Cooper lakes of Lake Marion and Lake Moultrie in South Carolina, the James River in Virginia, Powerton Lake in Pekin, Illinois, and Lake Springfield in Springfield, Illinois. It is also found in some lakes in Florida.[Hook and Bullet website, at http://www.hookandbullet.com/fishing-lake-placid-placid-lakes-fl/ .]
The blue catfish can tolerate brackish water, and thus can colonize along inland waterways of coastal regions.[Graham, K. (1999) "A review of the biology and Management of Blue Catfish." American Fisheries Society Symposium 24:37–49] It is considered Invasive species in some areas, particularly the Chesapeake Bay.
Evolution
The blue catfish is likely a direct descendant of
Ictalurus lambda, a prehistoric catfish that inhabited the central and southern United States during the
Pliocene. The bones of
I. lambda very closely resemble those of
I. furcatus aside from a few minor differences.
Identification
Blue catfish are often misidentified as
channel catfish. Blue catfish are heavy bodied, blueish gray in color, and have a dorsal hump.
[ Catfish in Lake Ouachita Retrieved 1 July 2016] The best way to tell the difference between a channel catfish and a blue catfish is to count the number of rays on the anal fin. A blue catfish has 30–36 rays, whereas a channel catfish has 25–29.
Blue catfish also have
barbels, a deeply forked tail, and a protruding upper jaw.
While adult blue catfish usually only grow to around they have been seen to grow up to at least in length and even weigh more than .
Diet
The blue catfish is an opportunistic
predator, eating any species of fish it can take (including cannibalism), along with
,
crawfish,
, freshwater
mussels,
,
,
, and other readily available aquatic food sources.
The species is noted for taking injured fish beneath marauding schools of
striped bass in open water in reservoirs, and feeding on wounded baitfish that have been washed through
dam spillways or power-generation turbines. It is one of the few species of fish in the Mississippi River basin able to eat adult
Asian carp.
Population
The blue catfish are a highly productive species, spawning once a year from May to June. Females can produce 2,000 to 4,000 eggs per pound (0.45 kg) of body weight, meaning a blue catfish can produce upwards of 40,000 eggs.
As an invasive
The ability of the blue catfish to tolerate a wide range of climates and brackish water has allowed it to thrive in Virginia's rivers, lakes, tributaries, and the Chesapeake Bay. Unfortunately, the relatively low mortality rate, large body size, wide range of species preyed upon, and success as a predator has resulted in the blue catfish being considered a problematic invasive species in Virginia. Since their introduction in Virginia waters in the 1970s,
[Greenlee, R. S., and C. N. Lim. 2011. Searching for equilibrium: population parameters and variable recruitment in introduced Blue Catfish populations in four Virginia tidal river systems. Pages 349–367 in P. H. Michaletz and V. H. Travnichek, editors. Conservation, Ecology, and Management of Catfish, the second international symposium. American Fisheries Society, Symposium 77, Bethesda, Maryland.] blue catfish populations have exploded. Recent electrofishing studies have documented capture rates in excess of 6,000 fish/hr,
whereas studies from the native range show peak electrofishing capture rates of 700 fish/hr.
[Boxrucker, J., and K. Kuklinski. 2008. Abundance, growth, and mortality of selected Oklahoma Blue Catfish populations: implications for management of trophy fisheries. Proceedings of the Annual Conference Southeastern Association of Fish and Wildlife Agencies 60(2006):152–156.
] Clearly, blue catfish are a dominant species within the
Fresh water and
Salinity portions of Virginia's tidal rivers. The introduction of blue catfish in Virginia's tidal rivers was thought to have negative impacts on anadromous
American shad,
blueback herring, and alewife; however, predation of these species by blue catfish has been demonstrated to be minimal.
[ ] Researchers from Virginia Tech have found the species to be mostly
Herbivore and
Omnivore, with diets consisting largely of
Hydrilla and Asian clams, both of which are invasive to the Chesapeake Bay.
Blue crab, the most valuable species in the Chesapeake Bay, was also found in the diet with some regularity.
Record-setting fish
An angling world record was set on May 22, 2005 with a blue catfish caught in the Mississippi River,
[ Blue catfish receives world record status from the IGFA Retrieved 5 September 2006][ IDNR Announces World's Largest Blue Catfish Caught Retrieved 5 September 2006 ] surpassing a specimen from
Lake Texoma in
Texas.
On June 18, 2011, a blue catfish was landed from Kerr Lake on the Virginia-North Carolina border. On June 22, 2011, the Virginia Department of Game and Inland Fisheries certified it as the new state record.[Dixon, Julia (June 22, 2011) News Release 143-Pound Blue Catfish Certified as State Record. Virginia Department of Game and Inland Fisheries.] The fish had a length of 57 in (145 cm) and a girth of 47 in (120 cm).
The hand-line record is a blue catfish on -test braided line caught June 5, 2015 on the Potomac River using a sausage with a circle hook.
See also
-
Flathead catfish ( Pylodictis olivaris), another very large North American catfish
-
Channel catfish ( Ictalurus punctatus), a species of North American catfish closely related to the blue catfish
Further reading
-
Johnson, Ryan (2015). Ryan Believes Everything He Reads. Alamogordo, Texas: Penguin Publishing. .
-
External links
