The little snail cichlid is supposed to build its nest out of an abandoned snail shell under observation. A new study shows that this behavior is innate. However, with a little practice, the animals become more and more skilled at building nests.
Many animal species build nests. One often thinks of warm, soft places in which animals can raise their young in a well-protected manner. Some fish species also prepare underwater nests for mating foreplay and for laying eggs. Cichlid males build nests out of sand and other materials to attract females – which in different species have their own shapes, from caves to hollows to hills. snail cichlids (Lamprolo ocellatus), which only occur on Lake Tanganyika in Africa, use abandoned snail shells as shelter and nursery.
Researchers at the Max Planck Institute have now examined in more detail how the snail cichlids build their nests. The fish first bury the snails in the sand and finally cover them with sand. This process usually takes around three hours. But even without prior contact with snail shells, the skilled underwater architects know that they can build a nest out of them and also know how to build the nest. The first time, however, it took them an average of 12 hours.
This shows that nest building behavior is innate. However, the scientists also observed that cognitive components such as the ability to adapt and learn play an important role. The fact that practice makes perfect with snail cichlids was shown when the test fish only needed four and a half hours to complete the third nest-building attempt.
The experiment also demonstrated the flexibility of the snail cichlids. They readily accepted modified external geometries of the 3D printed snail shells, including those of various sizes as well as left-handed snail shells, which are very rare in nature.