Miscellaneous Freshwater Fishes
Remarkably few European native fishes are kept by aquarists and yet some meet all the criteria of a good aquarium fish, that is, small size, pretty colours, and interesting behaviour. The sticklebacks meet all these criteria in full and yet are very rarely even thought of when choosing aquarium fishes.
The sticklebacks are a small family of fishes which live in fresh, brackish, and marine waters of the northern temperate zones. Two species make good inhabitants of the cool water aquarium. These are Pungitius pungitius (Ten-spined stickleback) and Gasterosteus aculeatus (Three-spined stickleback). In general it is best to house these species separately from each other in a single species aquarium about 60 cm (24 in) in length. Although they are schooling species, males become territorial during the^breeding season and will fight and badly injure each other if the aquarium is too small. It is wise, therefore, to keep only one male and a group of females.
When in breeding condition the male Gasterosteus aculeatus (Three-spined stickleback) developes a vibrant red coloration. At this time he is ready to entice a willing female into his nest.
The tank should have a fine gravel substrate, plenty of plants, and lots of caves and pots to provide hiding places. The water will need to be soft unless you can find a wild population which is living in hard water conditions. Aeration is needed to maintain the oxygen level during warm weather, and ideally the aquarium should be sited where the temperature will fall as low as possible (without freezing) during winter. This helps stimulate the fishes to spawn in the spring.
Once settled in they will spend much of their time out in the open looking for food. For fishes caught in the wild this will need to be live foods such as bloodworms, Daphnia, and whiteworms. It is a rare wild fish which can be weaned on to flake foods, but most will eventually accept frozen foods and small pieces of fish or meat.
During spring and summer the male will come into breeding condition and it is then that you see the real beauty of these species. Ten-spined stickleback males Gastromyzon turn a velvety black and have bright orange pectoral fins. Three-spined stickleback males develop the most beautiful red coloration over much of the body, particularly on the throat.
The male will select a suitable site and build a nest. This will be on the bottom of the aquarium in the case of the three-spined stickleback and a few inches above the bottom in the other species. It is made of pieces of plants stuck together with a “glue” produced by the male. Once it is complete the male will entice a ripe female into the nest and spawning will take place. As other females become ready to spawn they too will be invited into the nest to spawn. In between the male will look after the eggs and later guard the fry. The fry will eat newly hatched brine shrimp, and as soon as they are large enough to handle should be removed to another aquarium for rearing.
In this chapter we have introduced you to some of the more unusual fishes available in the hobby but it doesn’t end there. On this page we will give you just a taste of what else in the way of “oddballs” is out there if you are prepared to look. Some of these unusual species have bizarre habits and very specific environmental and dietary requirements, so don’t forget: NEVER purchase them on impulse, but always check on their size, behaviour, and needs first.