Short description of Ameiurus melas, Black Bullhead

Known as the black bullhead; a 'bullhead catfish' (family Ictaluridae) not related to native bullheads. All GB Ameiurus are A. melas, therefore records of A. nebulosus (brown bullhead) are incorrect.

Impact summary: Ameiurus melas, Black Bullhead

Detailed impacts not known, but its omnivorous feeding habit means that the species may impact on a range of invertebrates, plants and smaller fish as well as competing for food.

Habitat summary: Ameiurus melas, Black Bullhead

In GB, ponds and lakes. More widely, ponds, backwaters, and sluggish waters over soft substrates in small, medium and large rivers. Can survive in a range of waters, including those which are low in oxygen, brackish, turbid and/or very warm.

Overview table

Environment	Freshwater
Species status	Non-Native
Native range	Mexico, Eastern United States, South Eastern Canada
Functional type	Omnivore
Status in England	Non-Native
Status in Scotland
Status in Wales
Location of first record
Date of first record	1885

Origin

North America: Great Lakes to northern Mexico.

First Record

Introduced in the 19th century with the first GB record in 1885, although no location details are held.

Pathway and Method

Introduced as an ornamental species; possibly also escapes from aquaculture.

Species Status

Often misidentified as the brown bullhead A. nebulosus, which causes some confusion over its distribution. In Britain, all Ameiurus should currently be considered A. melas, with records of A. nebulosus seemingly erroneous. Recorded from Warwickshire in April 1989 with anecdotal reports of a persistent population in Essex; likely to be spreading now individuals have been found in rivers as well as ponds.

Also introduced to Albania, Belgium, Chile, Czech Republic, France, Germany, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Russian Federation, Spain, Switzerland and the former Yugoslavia. Some introductions are direct from North America, others from areas with previous introductions following the trade in this species.

Dispersal Mechanisms

Once released/escaped, dispersal via river systems, although details of distance not known.

Reproduction

Females lay eggs in the substrate in early spring and one or both parents guard them; eggs can number into the thousands. Fry are protected by both parents. Along with high physiological tolerance, fecundity and parental care are suggested as factors increasing the success of this species when introduced.

Known Predators/Herbivores

Any general piscivorous species.

Resistant Stages

None.

Habitat Occupied in GB

Little information is currently held, though most records and reports are from ponds and lakes. Some individuals have been found in rivers, facilitating the spread of the species.

The only record on the NBN Gateway is from Radway Grange Lake in Warwickshire (SP370480) on 27/04/1989. There are anecdotal reports of a persistent populations in Essex as well as reports of individuals in rivers, suggesting that this species is spreading.

Environmental Impact

Of the countries where it has been introduced in Europe, four report impacts on the ecological community due to dominance, three report bioaccumulation of pollutants, two report impacts due to competition (for food and/or space) with native species, and one reports impacts due to predation of native species. There may also be impacts (direct or indirect) through increased turbidity related to reduced macrophyte growth and reduced stability of substrates.

The generalist and opportunistic feeding habit has been analysed in Spain and Portugal (Leunda et al 2008) and indicates potential impacts on a wide range of potential prey species as well as impacts through competition. In this study, black bullheads consumed plant material, terrestrial prey and co-occurring fish species (native or exotic), taking the most abundant and available prey. With no positive relationship between black bullhead size and fish prey size, it is likely that they fed on dead or dying vulnerable fishes as well as predating smaller-sized active fishes.

Health and Social Impact

Can be a 'nuisance' species taking lines/bait intended for other species.

Economic Impact

None known.

Identification

Croft, P. (2006) Guide to British Freshwater Fishes. Field Studies Council, Preston Montford.

Page, L. (2007) Ameiurus melas (Rafinesque 1820) . Black Bullhead. http://tolweb.org/Ameiurus_melas/69827/2007.05.23 in The Tree of Life Web Project, http://tolweb.org/ [accessed 29/09/2010].

Wheeler, A. (1998). Field Key to the Freshwater Fishes and Lampreys of the British Isles. Field Studies Council, Preston Montford.

Biology, ecology, spread, vectors

Leunda, P.M., Oscoz, J., Elvira, B., Agorreta, A., Perea, S. & Miranda, R. (2008) Feeding habits of the exotic black bullhead Ameiurus
melas (Rafinesque) in the Iberian Peninsula: first evidence of direct predation on native fish species. Journal of Fish Biology, 73,96–114.

Marchetti, M.P., Moyle, P.B. & Levine, R. (2004) Invasive species profiling? Exploring the characteristics of non-native
fishes across invasion stages in California. Freshwater Biology, 49, 646-661.

Management and impact

Braig, C.B. & Johnson, D.L. (2003) Impact of black bullhead (Ameiurus melas) on turbidity in a diked wetland. Hydrobiologia, 490(1-3), 11-21.

Cucherousset, J., Paillisson, J.-M. & Carpentier, A. C. (2006) Is mass removal an efficient measure to regulate the North American catfish Ameiurus melas outside of its native range? Journal of Freshwater Ecology, 21(4), 699-704.

Natural England (2009). Horizon scanning for new invasive non-native animal species in England. [accessed 10/11/2010].

Savini, D., Occhipinti–Ambrogi, A., Marchini, A., Tricarico, E., Gherardi, F., Olenin, S. & Gollasch, S. (2010) The top 27 animal alien species introduced into Europe for aquaculture and related activities. Journal of Applied Ichthyology, 26 (Suppl. 2), 1–7.

General

FAO Fishbase www.fishbase.org [accessed 29/09/2010].

Page, L. (2007) Ameiurus melas (Rafinesque 1820). Black Bullhead. http://tolweb.org/Ameiurus_melas/69827/2007.05.23 in The Tree of Life Web Project, http://tolweb.org/ [accessed 29/09/2010].