Three Spiked Stickleback (Gasterosteus aculeatus)

Here is a sympathetic little fish that lives in the cold waters of the Northern Hemisphere. It is quite common in  coastal waters all around the World between the latitudes 35 and 70. The three spiked stickleback can be found in Europe, North America, and Asia. It can live in salt water as well as fresh water. It is also very common right here in my diving back yard, the brackish waters of the Baltic Sea.

The three spiked stickleback is normally only about five centimetres, or two inches, long. It is bright silvery in colour and has three distinct, sharp spikes on the back that he can lift up when threatened. Hence the name, three spiked stickleback, of course.

The breeding habits of the three spiked stickleback are quite peculiar and intriguing. In the springtime, during spawning season, the male three spiked stickleback builds a little, dome-shaped nest out of water plants and weeds on the sea bed. He then begins to court the females of the species by showing off his zig-zag mating dance in the water outside his nest.

Once the female three spiked stickleback is adequately impressed, she lays her eggs  in the nest. After that the male fertilizes the eggs. Then he dumps her and goes on to hit on other females. Sometimes one male can have the eggs of close to a dozen females in his nest, one batch on top of another.

The male three spiked stickleback fiercely defends and takes care of his offspring until they are old enough to find their own food and survive independently.

Outside of breeding season the three spiked stickleback lives in large shoals. They eat small invertebrates, larvae and fish eggs.

Well, that's it this time. It has been a while since I last wrote here, hopefully I'll be able to find the time to write more often. Anyway, if you have any comments, feel free to comment below. All feedback will be greatly appreciated. Dive safe!