The Gasterosteidae are a family of fish including the sticklebacks. They are related to the pipefish and the seahorses. FishBase recognises species in the family, grouped in five genera. It has long been a subject of scientific study for many reasons.

It shows great morphological variation throughout its range, ideal for questions about evolution and population genetics.

Bufret Lignende Oversett denne siden Stickleback , any of about eight species of fishes in five genera of the family Gasterosteidae (order Gasterosteiformes) found in fresh, brackish, and marine waters in temperate regions of the Northern Hemisphere as far north as the Arctic Ocean. Sticklebacks are small, elongated fishes that reach a maximum length of about . One difference is the amount of protective armor that covers their bodies: while oceanic sticklebacks have about . Its most diagnostic characters are the number of dorsal spines, of which there are three . It is a small, beautifully streamline torpedo shaped fish, with a broad tail fin. The Stickleback family includes five genera and some seven species that are found across temperate areas of the Northern Hemisphere.

Four Stickleback species are native to North America.

Adults measure at most some five or six inches long. The Environment Agency, the University of Leicester and Gledhow Primary School have developed a project. Description: small, fairly deep body. The three- spined and ten-spined may be found in Britain.

Stickleback , of the fish family Gasterosteidae, occur in freshwater lakes and streams and in marine waters along northern coastlines of the northern hemisphere. A tiny, scaleless, freshwater fish, the highly endangered unarmored threespine stickleback is a fierce protector of its nest, which it defends by dashing forward with gaping mouth and “hackles” raised. Only two inches long, and bright-red when mating, male sticklebacks patch their nests together with mucus threads spun from . Three spines in front of the. The fish known collectively as “stick- leback species pairs” are small, freshwater fish which are of particu- lar scientific interest because of their evolutionary history and their extreme- ly limited distribution. Appearance: As in other sticklebacks , the body of the nine-spined stickleback tapers to a very narrow caudal peduncle leading to a fan-shaped caudal fin.

Resembles its three-spined cousin but body not as deep. The most reliable means of identification is . Appearance: Like other members of the family, the brook stickleback has a body tapering to a slim caudal peduncle and fan-shaped tail. Closely resembles the nine-spined stickleback but has only five, sometimes six, dorsal spines.

Also lacks lateral bony plates.

Colouring: Outside the spawning season the overall colour is . Apeltes quadracus, fourspine stickleback , I, benthopelagic, weedy bays.