Latin name: Cottus gobio
The bullhead, also known as Miller's thumb is present but not common in most of England and Wales. At a European scale this species is comparatively rare which makes the UK population of European significance. The bullhead is a small bottom-dwelling fish that inhabits rivers, streams and stony lakes, with fast-flowing, clear, shallow water with a hard substrate. They are also said to be found in the headwaters of upland streams. The bullhead is a short-lived species (3-4 years), which matures early and spawns several batches of eggs each year between February and June. It feeds on small invertebrate species such as freshwater shrimps, mayfly nymphs and caddis larvae. Nationally the population is thought to be declining due to the lowering of the water table and changes in drainage due to agricultural and forestry pressures. Due to the European significance of the UK population the bullhead is listed in Annex II of the EC Habitats Directive 92/43/EEC, which has been translated into UK legislation and is known as the Habitat Regulations of 1994. In the Yorkshire Dales National Park, rivers in which the bullhead has been formally recorded include the Wharfe, the Ribble, the Dee (Dentdale), the Clough River (Garsdale), the Swale and the Ure catchment. In 2007 bullhead was found frequently in the Ure catchment as part of a PhD project based at Durham University. The Rivers Trusts are carrying out numerous practical measures to benefit river catchments. The Yorkshire Dales Biodiversity Forum is organising a Rivers conference in November 2013 and the Catchment Sensitive Farming project also has significant benefits for river species.