World-first research helps protect sea anemones

Host sea anemones and the anemonefish they provide homes for will have a more certain future thanks to world-first research by Southern Cross University PhD student Anna Scott.

Anna, who is based at the National Marine Science Centre in Coffs Harbour, and her supervisor Associate Professor Peter Harrison have obtained a provisional patent for a method of breeding the host sea anemones in captivity.

Host sea anemones play an important role in the marine environment, providing a home for the much-loved anemonefish - made famous in the film 'Finding Nemo'.

"There are about 1000 species of sea anemones, however only 10 provide a central home for anemonefish. Without these anemones, fish such as 'Nemo' wouldn't be able to survive in the wild," Anna said.

"Due to the fascinating relationship between anemonefish and their host anemones, these animals are highly prized for the aquarium trade. The success of 'Finding Nemo' has further increased their popularity.

"In many countries the unregulated exploitation of these anemones is causing the depletion of local populations and in some areas this actually threatens their existence."

While there have been studies on the reproductive cycle of the anemonefish, this is the first scientific study on the reproductive cycle of the host sea anemone.

After studying the host sea anemones for more than three years, which included many long nights watching and waiting for the anemones to spawn, Anna has documented the reproductive biology of two species of host anemone for the first time.

With a patent now in place, Anna is hoping she will be able to obtain backing to develop a captive breeding program to supply the aquarium trade and also provide animals to restock areas already degraded.

Her work has been based in the Solitary Islands Marine Park, off Coffs Harbour, which is home to the world's highest known density of host sea anemones.

She said she became enthralled with the animals when she saw them spawn for the first time in a tank at Heron Island while completing her Honours year on coral reproduction, also with Professor Harrison at Southern Cross University.

"I was walking back from getting a chocolate bar and I saw one of these anemone spawning and it was just incredible. The spawning goes for about two hours. The males release numerous bursts of sperm and the females release eggs which float up to the water surface. Fertilisation occurs externally in the water column, and within the tanks fertilisation rates are very high," Anna said.

Her intense interest in the reproductive cycle of these creatures might also stem from something in her own genes. Anna's grandfather Mervyn Griffiths, also a scientist, played a key role in discovering how echidnas and platypus reproduce.