Overview:

Black bullhead is a ray-finned, freshwater catfish native to eastern North America, from the Great Lakes to northern Mexico.¹
Mature black bullheads are nocturnal and omnivorous, feeding on clams, snails, plant material, frogs, and other fishes. Juveniles feed on planktonic crustaceans.¹ Bullheads will eat early anything that can fit in their mouth.⁴
As of January 1, 2016, the possession, sale, or transport of this species in Alberta is unlawful under the Fisheries Act.

Habitat:

Black bullhead inhabit areas of sluggish current over soft substrates in creeks and rivers, such as oxbows, pools, and backwaters. It occupies soft to hard waters with a pH 6.5-8.0, and temperatures of 8°C to 30°C.¹ Bullheads can tolerate murky waters and low oxygen content.⁴

Identification:

Black bullheads are greenish-brown to black on the dorsal side and yellow on the ventral (bottom) side. There is a light-coloured vertical bar across the base of the tail. Bullheads have no scales.⁴ Anal fin rays total 15 to 21. Average length at maturity is 15-25 cm and rarely over 35 cm.¹ There is a single sharp spine in the dorsal and pectoral fins used for defense and ejects a mild poison. The poison is harmless to humans but may cause stinging.4 The membranes of the dorsal fin are noticeably darkened.³
The adipose fin (between dorsal and tail fins) is fleshy, free at the posterior and well separated from caudal (tail) fin. Caudal fin is round. There is no bony ridge between the head and origin of dorsal fin; this area is compressible.⁴ Black bullheads have four pairs of darkbrown to black barbels, the ones at the mouth corners almost twice as long as the barbels near the nostrils.³ The barbels and the entire body of bullheads are covered with tasebuds.⁴

Ecology:

Black bullheads excavate shallow depressions in sand or mud bottoms for spawning late spring into summer.² A mating pair will slide their barbels over the body of the other and the female releases eggs when the male wraps his caudal fin around her head. Pairs spawn up to 5 times in an hour with the female fanning the eggs between spawns.Both sexes guard the eggs.¹ Black hatchlings swarm near the surface as the parents protect the school.²

Economic Impacts:

Black bullhead directly compete for food and space with larval and some adult fish which may have value as sport fish or the commercial fish market.

Environmental Impacts:

Black bullhead have the potential to deplete invertebrate populations which can lead to reductions in native species which rely on invertebrates for food.¹

Sociological Impacts:

Loss of native fish species and transformation of fish communities results in the intrinsic loss of natural capital and enjoyment of natural areas.

Prevention:

Accidental and intentional releases are responsible for Black bullhead introduction and spread. Range expansion may also occur if introduced fish move into and colonize other rivers and lakes.

Control:

Currently, there are no established control options for black bullhead in Alberta other than recreational fishing and capture.

References:

¹Froese, Ranier and Pauly, Daniel, eds. (2005). Ameiurus melas in FishBase. November 2005 version. www.fishbase.ca/summary/291. Accessed: January 8, 2016.
²Minnesota Department of Natural Resources. www.dnr.state.mn.us/fish/catfish.biology.html. Accessed: January 8, 2016.
³Scott, W.B. and Crossman, E.J. 1973. Freshwater Fishes of Canada. Bull. Fish. Res. Board Can. 184:1-966. Ref No [1998] Key No. [88] www.fishbase.org/keys/questions.php. Accessed January 31, 2016.
⁴Species Profile - Bullheads: Minnesota Department of Natural Resources. www.dnr.state.mn.us/minnaqua/speciesprofile/bullheads.html. Accessed: January 21, 2016.