Heritability of growth traits in South African Abalone (Haliotis midae L.) using the ‘internal reference’ method

Abstract

The South African Abalone Haliotis midae is a vital aquaculture species, accounting for the highest percentage of total aquaculture production revenue. Improving the growth rate and thus, reducing operational costs with associated benefits in production efficiency and profitability is a priority of producers. The industry has been reluctant to implement anything but the most rudimentary breeding practices, due to unreliable tagging methods and the cost of using DNA markers. As such, the current study aimed to estimate genetic parameters for growth traits in the absence of individual tagging or DNA markers using the ‘internal reference’ method. The requirements of the internal reference method are evaluated and the merits and demerits considered. Heritability estimates were low to moderate in magnitude for wet weight (0.06–0.21) and shell length (0.11–0.16). It is concluded that substantial genetic gains can be achieved through selection and further work into developing strategies employing individual identification and DNA markers are warranted. Statement of relevanceWe adapted an existing statistical control method in an innovative way to estimate genetic parameters for growth traits in abalone, without individual tagging or DNA markers. This method facilitates the transition from simple family selection programs to combined selection programs by providing the necessary inputs for bio-economic modelling to inform the design of more advanced breeding programs.