Baby corals use sound cues to reach home

Washington, May 15 (ANI): Coral larvae, just like their older counterparts, can use sound as a cue to find coral reefs, found researchers.

Many years ago, Dr Steve Simpson, Senior Researcher in the University of Bristol's School of Biological Sciences discovered this behaviour in baby reef fish.

However, their Dutch collaborators in Curacao started finding that coral larvae - which must quickly find a safe place to land and establish a colony or they will die - can also act on sound cues to head home.

The team designed a 'choice chamber' (a device that offers small invertebrates two or more contrasting conditions and allows them to move freely towards the one they prefer), put coral larvae into it and played them recordings of a coral reef.

The results clearly showed that the flea-sized larvae were strongly attracted to the noise as they seek a suitable habitat.

Coral larvae look like tiny eggs covered in hairs, and come from the same group of animals (Cnidaria) that also includes sea anemones.

While it is unknown how these simple creatures detect sound, Dr Simpson said: "At close range sound stirs up water molecules, and this could waggle tiny hair cells on the surface of the larvae, providing vital directional information for baby corals."Corals aggregate to form vast reefs, which are now one of the most threatened ecosystems in the world.

Due to global warming and ocean acidification, some experts have suggested coral reefs are now on Death Row.

Understanding how these vulnerable animals complete their life-cycle is essential to ensure appropriate management.

Since corals, like fish, respond to reef sounds then the masking effects of human noise pollution in coral environments is of extra concern.

"Anthropogenic noise has increased dramatically in recent years, with small boats, shipping, drilling, pile driving and seismic testing now sometimes drowning out the natural sounds of fish and snapping shrimps," said Simpson. (ANI)