How do fish find their way home?

Have you ever wondered in the vast ocean, how can small fish know the way back?

Jelle Atema, biologist of sensory research at Boston University and Gabriele Gerlach (Woods Woods Marine Laboratory, Massachusetts, USA) analyzed a number of small gene groups called microsatellite in 3 species. Fish include cardinal fish , fish damsel spikes and damsel neon fish living in 5 coral reefs in the Great Barrier Reef, Australia.

Through research, they found that these three species of fish returned to where they were born more than other fish. Especially for cardinal fish, they have differences in the coral reef genes that they produce.

To find out what led the cardinal fish back to " home ", the scientists placed cardinal fish larvae in a body of water that included many streams of water coming from other coral reefs. Research shows that cardinal fish larvae prefer water from coral reefs to " home " them and will stay there for longer periods. Researchers believe that these young creatures can detect the " smell " in the water and this smell has led them home.

Cardinal fish larvae (Photo: LiveScience)

3-week-old cardinal fish larvae " sniff " in a similar way to humans, except that their environment is water and they can sniff out soluble substances in water.

In most coral reef fishes, females will lay eggs and males fertilize and protect the eggs until they become larvae. During the first week, the larvae floated and circled their hidden areas. As they grow, their transparent bodies become like big fish and they swim faster and can move around without disorientation.

However, there is still an unanswered question as to why the larvae can "learn" the scent from the coral reefs they reside in? . Scientists hope to detect which chemicals have formed the smell of coral reef habitats.

MINH ANH