Bullhead (Cottus gobio)

Scientific name: Cottus gobio Linnaeus, 1758

The Bullhead (Cottus gobio) is a freshwater fish of the family Cottidae. In the aquarium it needs water at 1–16°C (34–61°F).

Bullhead care at a glance

Temperature: 1–16°C (34–61°F)

Biology

Occurs in cold, clear and fast-flowing water of small stream to medium-sized rivers as well as on gravel or rocky shores of cold lakes and in slightly brackish waters along eastern coast of Baltic coast. Feeds on small bottom invertebrates, mainly insects, crustaceans. Pink to yellow eggs are found in clumps attached to undersides of large stones. Contrary to statements in older literature, eggs and larvae of fishes are not a common food item.

Source: FishBase, licensed CC BY-NC 4.0.

Species facts

Scientific name: Cottus gobio
Family: Cottidae (Sculpins)
Order: Scorpaeniformes (Scorpionfishes and Flatheads)
Class: Actinopterygii (Ray-finned fishes)
Maximum length: 18.0
Common length: 10.0
Depth range: 2 m (7 ft)
Environment: Freshwater; brackish;; pH range: 7.0 - 7.5; dH range: 10 - ? demersal; potamodromous; depth range 2 - 2 m
Climate: Subtropical
Distribution: Europe: North Baltic in Scandinavia south to stream Maurine in southwesternmost of corner of Baltic basin (Germany); lower reaches of streams and rivers and along coast of Sweden, Finland, Russia southwest to Estonia.; Danube (except upper tributaries Save and Arges), Elbe, Ems, Weser and Rh?ne drainages;tributaries of upper Rhine downriver (northward) to about Mannheim; a few of uppermost tributaries of River Tevere, central Italy; Adriatic drainages from Potenza in Italy to Zrmanja in Croatia, except Timavo spring. Locally introduced in Scheldt drainage in Belgium. Records of sculpins from Neretva drainage in Bosnia-Herzegovina possibly belong to Cottus gobio.
Conservation status (IUCN): Least Concern (LC)
Threat to humans: Harmless
Uses: Fisheries: of no interest; bait: occasionally
Resilience: Medium, minimum population doubling time 1.4 - 4.4 years (tm=1-3)

Sources

Taxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.

Last updated 27 September 2026