Wednesday 27 February 2013

Three-spined Stickleback



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Looks

Sticklebacks are small fish only a few inches long, with spiky fins running down their back. Interestingly, Sticklebacks have no scales. Some species, however, have armour plates to protect them. Three-spined Stickleback females are light blue-green with a pale pinkish underbelly, and the males of this species are the same, but with a silver belly instead of pink.

Habitat

These little fish live mostly in the ocean. Some also make their homes in freshwater lakes. Long ago, after the ice age, glaciers and ice melted, allowing the Sticklebacks to make homes in the freshwater lakes and streams. In there, the predators were faster but not as strong, so the freshwater Sticklebacks evolved to suit their new territory’s needs. The freshwater species have no spines or armour plating, and are faster and more agile than their cousins in the sea.
The ocean Sticklebacks live only in the Northern Hemisphere, prefering coastal, slow-flowing water with marshes and bays.

Feeding

Sticklebacks’ diets consist of small crustaceans and the lavae of fish.

Breeding
(Three-spined Stickleback—other species have a similar way of breeding)
First, the male fish creates a bird-like nest out of vegetation. Then he attracts a female and invites her inside. The female Stickleback will lay a clutch of about 100-150 eggs. Afterwards, the male guards the nest, driving away other males and protecting the eggs until they hatch.

Lifespan
(Three-spined)
These small fish live for about 3 years.