Gene test breeds pedigree abalone

The world’s fastest growing abalone—the tropical donkey’s ear abalone, Haliotis asinina—can be bred to grow rapidly and reliably for aquaculture, Queensland biologists have found. And that makes it potentially a high value alternative crop for struggling prawn farmers.

The researchers looked at whether they could speed up breeding of abalone for aquaculture using modern technology to identify and select genes that are activated in fast-growing animals. By linking the abundance of specific genes with fast growth rates, they have now shown their proposal is practical.

“If we can select breeding individuals who grow rapidly, the chances are that they have the right underlying genetic instruction manual, which can be passed on, ensuring their progeny grow fast as well,” says Tim Lucas from the Queensland Department of Primary Industries and Fisheries, who worked on the project with Prof Bernie Degnan of the University of Queensland.

The work has already demonstrated that growth rate is highly heritable—that fast-growing animals from the wild are likely to lead to fast-growing progeny in aquaculture. And the researchers have also developed methods for a simple blood test to measure the abundance of rapid-growth genes in wild abalone. This opens the possibility of pre-selecting fast-growing broodstock, reducing the level of undesirable genes from the start.

“Using these molecular techniques to select individuals for breeding rather than traditional physical traits, we can get one step closer to the fundamental genetic differences that control growth rate,” Tim says.

“It is difficult to go out onto the reef, tag and release abalone, and physically measure growth as it’s occurring. Using these molecular tools, however, we can take a blood sample and determine the activity of the growth genes. That immediately provides us with a snapshot of how fast individuals are growing at a particular point in time.”

The availability of these molecular tools increases the feasibility of farming donkey’s ear abalone in Australia, leading to rapid improvements in profitability.

“Not only are donkey’s ear abalone potentially of high value, but they are also plant-eaters,” Tim says. “This is important because it means they could provide a sustainable alternative option for tropical prawn farmers who are currently struggling to compete with cheaper imports and the soaring price of fishmeal.”

Because all abalone species are closely related and share most of their genes, says Degnan, it is likely the findings of the research team could also be applied to the more lucrative temperate abalone aquaculture industries in Australia and around the world.

Tim Lucas is one of 16 early-career scientists chosen for Fresh Science, a national program sponsored by the Federal and Victorian governments. He is presenting his research to the public for the first time.