Cottus gobio

Bullhead
92/43/EEC Directive  ann. II

Species spread throughout Europe, small in size (up to 15-16 cm) with a large and flattened head, with bare skin or covered with small spines, with fins well developed and dorsal ones very tight. The background color varies from dark gray to greenish brown with irregular darker spots on the back and sides; the belly is white, the dorsal, pectoral and tail fins are clear with dark spots arranged in regular lines. The species is benthic and is very demanding in terms of environmental quality. It requires fast, cold and well-oxygenated waters with substrates consisting of boulders, pebbles and gravel. It lays its eggs under rocks and gravels and the male guards the nest until hatching.
The feeding is varied, it is composed by insect larvae and crustaceans during the summer, integrated with annelids during the winter.
The species is in decline and the causes are to be found in the alteration of river channels, in pollution of waterways, in excessive water abstraction and massive re-population of salmonids (strong impact in terms of predation).