You are what you eat ...

Sought after as a delicacy the world over, perlemoen has been poached and over-harvested in South African waters to the point that government has had to declare an outright ban on the gathering of it from the wild.

Stimulated by rising market prices, farming of perlemoen began in the 1990s based on a research and development partnership between industry and university researchers.

This investment has resulted in South Africa becoming the largest perlemoen producer outside Asia, where perlemoen is regarded as the crème de la crème of molluscs. Indeed, perlemoen is responsible for more than 60% of South Africa’s aquaculture industry, with almost 1 000 tonnes produced annually.

It’s easy to see why the poachers of this tasty shellfish risk so much—fresh perlemoen can fetch up to $30 a kilogram and is in huge demand, so much so that trucks carrying it require the sort of security normally used by cash-in-transit carriers.

So how exactly do you farm perlemoen?

It’s not a ‘normal” farm by any stretch of the imagination. Huge tanks of sea water house the molluscs, which are fed a pelleted food. This ‘food” was the subject of a Thrip project, under the leadership of Rhodes University researcher Dr Niall Vine, whose team was instrumental in developing a health-boosting probiotic to add to the feed.

Farming perlemoen is not without its challenges, says Vine. The tanks, known as ‘raceways”, differ from the molluscs’ natural habitat, which makes the perlemoen more susceptible to disease. All of this has led to the current Thrip project, co-funded by a consortium of three perlemoen farms: HIK Abalone, Aquafarm and Marifeed.

The consortium is finding ways to boost the molluscs’ immunity and growth rates. Vine explains that molluscs do not possess an immunity memory, which precludes vaccination.

But, Vine and his team have been researching ways to develop an immunostimulant probiotic diet supplement that enhances the perlemoen’s immune system, while simultaneously boosting its growth during the course of normal feeding. All of this demonstrates that, where perlemoen is concerned, you are what you eat.

The two immunostimulants Vine’s team has been working with are spirulina and spent brewers’ yeast. These have been included in various versions of the formulated food product, known as Abfeed S34.

Tests done on control groups of perlemoen have shown that this probiotic supplement has achieved its goal of boosting immunity and improving growth.

The team is now working with Rhodes University’s department of biochemistry, microbiology and biotechnology to develop methods to mass produce the probiotics for the supplemental diet.