Sturgeon or sterlet
The sterlet (Acipenser rutheneus) is the commonest sturgeon, spending all its life in freshwater. They are an extremely interesting family of primitive fish and are quite distinct from all the other living bony fish.
A non-native species in the UK popular with aquarists and pond fish-keepers. It's possible that introductions to the wild have come from well-intentioned aquarists and pond-keepers releasing fish that have grown too large for their tank or pond.
Appearance: they are relatively small in size compared to their beluga stugeon cousin that can reach 1,220kg in weight and 4.24m in length. The body is elongated with no scales, but has a characteristic row of bony plates that run along the sides of the body. They are usually sandy brown to dark olive in colouration. The tail is upturned and asymmetric in shape. The head is long and pointed with an upturned snout and four sensitive barbels.
Typical weight: 6lb
Lateral line scale count: 55-70 bony plates which run along the sides of the body
Lifespan: up to 100 years
Last date edited: 24 December 2020