10 20 40 60 cm
mittakaava > 60 cm
Gösta Sundman: Suomen Kalat (Kansalliskirjasto, The National Library of Finland), Lauri Urho, Petri Savola (Uudenmaan ympäristökeskus)
- Family: Carps and minnows – Cyprinidae
- Similar species: chub, ide, roach, rudd, vimba
- Size: 40–75 cm, 1–3 kg, can reach 5 kg or even more.
- Appearance: The asp is one of the fastest growing members of the carp family and can grow to a considerable size. Its streamlined shape resembles that of a salmonid, but the asp has no adipose fin. The pointed snout and longish anal fin are somewhat reminiscent of the vimba. Unlike the vimba, the lower jaw is longer than the upper. The large mouth extends to below the mid-point of the eye. The thickened tip of the lower jaw fits into a depression in the upper jaw. The eye is relatively small, and this is most noticeable in larger specimens. The long anal fin has 15–17 rays, the leading ones being longer, making the fin sharply pointed and strongly concave. Caudal fin large and deeply forked. Scales smaller than most other cyprinids, numbering 65–75 along the lateral line.
- Colouring: Smaller specimens are silvery with dark backs. Like other cyprinids, large specimens acquire a slight goldish tinge to the head and flanks. Underside fins pale reddish, caudal and dorsal fins bluish grey.
- Reproduction: Asps do not reach sexual maturity until they are comparatively old and have reached over 1 kg in weight. They migrate in May to spawn in fast-flowing water.
- Food: Small fish including bleak, smelt and roach.
- Distribution and habitat: Natural populations of asp occur in the rivers Kokemäenjoki and Kymijoki and in the Vuoksi system in SE Finland. Numbers in Finland were dwindling, but have been strengthened since the 1980s by stocking with reared fish. Asps have been introduced into numerous large lakes in S and SE Finland. They can also be encountered in estuaries along the Gulf of Finland.
- Endangerment: Near threatened.