Sea horses

24februari2010
Bron: National Geographic News
Seahorses are remarkable sea creatures, with a head that looks like a horse and a long snout. Firmly upright they swim into the wild sea, often floating on the current with their tail curled around a plant. There are 35 different species of seahorses, varying in colour and size.
How seahorses have obtained their unusual characteristics has for a long time been a huge scientific mystery, because there are so few seahorse fossils. The skeleton consists of very delicate, brittle bones. To investigate the evolution of the seahorse, scientists Peter Teske and Luciano Beheregaray compared the genes of seahorses with the genes of pigmy pipehorses, their nearest relatives that do have a horizontal swimming position like other fish.

The conclusion of the research was that the two species started to diverge about 25 million years ago. This coincided with strong tectonic activity which induced new ecosystems to develop in shallow coastal waters. Seagrasses started to grow abuntantly in these shallow waters. However, this is not a very attractive environment for horizontally swimming fish. The ancestors of the sea horse were forced to change their posture and appearance to their changing environment.

Results of this research were published in the scientific journal Biology Letters.