Cottus gobio - Bullhead

Taxonomy

Phylum: Chordata

Class: Actinopterygii

Order: Scorpaeniformes

Family: Cottidae

Bullheads are found in clean, fast-flowing shallow rivers in many parts of Wales, whereas in much of Europe these are now quite rare species. Bullheads are also sometimes found in shallow gravel-bottomed lakes. They lay their eggs in March and April, and the male guards the eggs until they hatch (although once they hatch he may eat a few of the youngsters if they come close enough).

These small, bottom-hugging fish are also known as Miller's Thumbs. They rarely grow to greater than 10cm long. (A bullhead weighing just 1oz currently holds the British rod-caught record for this species.)

Larger fish such as barbel are not averse to the occasional bullhead for lunch, despite the protection of the spiny dorsal and pelvic fins and the backward-curved spines that project from each side of the large head.