Care
The Stickleback has a wide area of natural distribution, occurring in most inland coastal waters within the northern hemisphere. Here, they are found in a variety of shallow, heavily vegetated freshwater and brackish environments, including lakes, rivers, streams, and estuaries over muddy or sandy substrates. Some populations are anadromous, spending most of their lives in saline waters, only ascending rivers in order to spawn; yet other populations spend their entire life cycles in pure freshwater. The anadromous fish tend to be larger, attaining a maximum size of around 11cm, but the freshwater fish that are suitable for housing in small ponds (or coldwater aquariums) top out at just 5cm. Sticklebacks are an ideal species for smaller ponds where no other fish are present, however, be aware that they may have a deleterious effect on insect and amphibian populations. This is due to the Sticklebacks being highly efficient micro-predators, making short work of any small eggs and larvae that they come across. Avoid keeping with larger fish, as the Sticklebacks may end up on the menu themselves. Filtration, although essential, need not be too powerful, and regular partial water changes will help to keep nitrogenous waste to a minimum. Provide an abundance of aquatic plants (marginal, oxygenating, and floating) for the fish to hide in and forage amongst. Sticklebacks are gregarious most of the time, so should be kept in good sized groups. However, they will become much more territorial when breeding, so having ample vegetation will help to diffuse any territorial disputes and break up lines of sight, as well as providing a spawning medium. May also be seen on sale as the Three-spined Stickleback.
Feeding
Will feed on natural foodstuffs within the pond, such as tiny crustaceans, amphibian eggs, and insect larvae. Supplement the diet with small meaty frozen foods such as bloodworm, white mosquito larvae, and daphnia, along with a good quality pond flake food.
Breeding
When ready to spawn, male fish take on spectacular nuptial colouration and become much more territorial. Each male fish will then dig a pit and build a nest in it that is comprised of plant material held together with a glue-like substance known as spiggin, a glycoprotein excreted by the kidneys. Once the nest is complete, the male will perform a courtship dance consisting of zigzag movements in order to entice a female into spawning. If the female is receptive, the male will take up a head-down position to signal where the entrance to nest is, and she will enter and deposit a few hundred yellow/orange eggs. The male immediately drives her from the nest and he then enters to fertilise the eggs. The male may choose to court further females and entice them one at a time to the nest, where more eggs are laid and fertilised. Females have also been known to lay eggs in several different nests over a period of several days. The male fish guards and aerates the eggs with his pectoral fins, and hatching should occur within 7-8 days at 18 °C. Paternal care continues for several days, with the male guarding the young at the nest site, and any that stray too far are quickly sucked up into his mouth and then deposited safely back in the nest. Once the young disperse, the male will either abandon the nest or repair it for another breeding cycle.
