Bullhead Or Miller's Thumb (cottus Gobio) And Alpine Bullhead (cottus Poecilopus)
The bullhead is a small, rather sedentary fish, with a large head and wide mouth, which inhabits the clean mountain brooks of the trout zone clown to small, lowland rivers. Its scaleless body has two dorsal fins. The pelvic fins are whitish and relatively short — they do not extend as far as the anal opening; the inside rays of these fins are over half the length of the longest ray. This fish usually rests under stones and has the advantage that it can adapt perfectly to the colour of its environment. It breeds in April and the male guards the eggs, which are usually stuck to the underside of large stones. It feeds on insect larvae and also is considered (without adequate proof) to be a dangerous predator on trout spawn. It lives throughout Europe from England and the Pyrenees to the Caspian Sea, but it is generally missing in the waters of southern Europe and western and northern regions as Ireland, Scotland, Scandinavia and the north of the USSR.
The Alpine bullhead is similar to the bullhead, although its pelvic fins are differently coloured. They have transverse stripes, are longer and often extend beyond the anal opening. The inside ray of the pelvic fins is short and does not exceed two fifths of the longest ray. It inhabits the watershed of the Arctic Ocean to the east of Scandinavia, also the watershed of the Baltic Sea and the rivers Danube and Dniester. It is generally found at higher altitudes above sea level than the bullhead.
Cottus gobio
Maximum size and weight: 15 cm, 80 g.
Identifying characteristics: Large head, lateral line complete. Inside ray of pelvic fins more than half the length of longest ray. Pelvic fins white-grey without transverse stripes.
Coitus poecilopus
Maximum size and weight:
15 cm, 80 g.
Identifying characteristics: Pelvic fins relatively long, extend to anal opening,
have transverse stripes. Their inside ray very short, does not reach half the length of the longest ray.
