Taxonomy
Squalius cephalus | Chub | Plobán
Distribution
Status
Conservation status
Least Concern
Legal status
Third Schedule listed species under Regulations 49 & 50 in the European Communities (Birds and Natural Habitats) Regulations 2011. (Note: Regulation 50 not yet enacted).
Native status
Non-native
First reported in the wild
2005
Invasiveness
Invasive species - risk of High Impact
Irish status
Established
Introduction pathways - 1
Release in Nature
Introduction pathways subclass - 1
Fishing in the wild
Invasive score
18
NAPRA Ireland risk assessed
No
Species Biology
Identification
Freshwater fish 30-45cm in length, weighing 0.5-1.5kg, elongate body with large, dark edged scales (Welby, 2004). Green/brown back with brass coloured flanks and a off white underside with dark fins, pelvic fins occasionally reddish (Welby, 2004).
Ecology
Fry and juvenile chub feed predominately on insect larvae but adult fish are piscivorous (Caffrey et al., 2008), meaning the potential exists for competition with, and predation of, native fish at higher population densities than currently occur in Ireland.
Habitat
Inland surface waters
Reproduction
Males sexually mature 3-4 and females at 4-5 years of age (Welby, 2004), spawning in shallow riffles over gravel or stoney substrates, to which the eggs adhere, in May or June with eggs hatching after 5-9 days depending on water temperature (Caffrey, 2008; Welby, 2004).
Pathway and vector description
Almost certainly deliberately released by anglers, first reports of the fish were in 2001 but were unconfirmed, the river Inny is attached to the Shannon catchment and would allow the species to spread further in Ireland (Caffrey et al., 2008). There is also the possibility of further deliberate human mediated spread.
Mechanism of impact
Competition, Hybridisation, Interaction with other invasive species, Other
Broad environment
Freshwater
Habitat description
In Britain mainly found in lowland sections of large rivers with moderate flows (Welby, 2004) though favour shallow water with gravel banks and moderate to high water flow for spawning (Caffrey, 2008).
Species group
Vertebrate
Native region
Europe
Distribution
World distribution(GBIF)
Irish distribution
Established - Localised & Rare. Restricted to the river Inny and an eradication program is in place (Caffrey et al., 2008).
Native distribution
Native to most of Europe, from Turkey to Britain, only absent from Ireland and some of the Mediterranean islands (Welby, 2004).
Temporal change
Date of first record category
2001-2010
Fifty year date category
2001-2050
Records submitted to Data Centre in 2024
The following map is interactive. If you would prefer to view it full screen then click here.
How can you help
Report any sightings to the National Biodiversity Data Centre.
References
Publications
Caffrey, J. M., Acevedo, S., Gallagher, K., & Britton, R. (2008). Chub (Leuciscus cephalus): a new potentially invasive fish species in Ireland. Aquatic Invasions, 3(2), 201-209. Webly, I. (2004) Chub Leuciscus cephalus In: Freshwater fishes in Britain the species and their distribution Davies, C., Shelley, J., Harding, P., McLean, I., Gardiner, R. & Peirson, G. (eds) Harley Books, Essex.