Simao Zacarias’s work focuses on the standard shrimp hatchery practice of unilateral eyestalk ablation to achieve higher egg production.
He has discovered that not only is ablation cruel, but it is unnecessary and increases vulnerability to disease, the GAA reported in its Advocate newsletter.
Based on evidence from his research in shrimp hatcheries in Honduras and Thailand, Zacarias proved in laboratory testing that post larvae and juveniles from non-ablated Pacific white shrimp broodstock showed higher survival rates when they were challenged with Acute Hepatopancreatic Necrosis Disease, also known as Early Mortality Syndrome, and White Spot Virus Disease.
The Institute of Aquaculture (IoA) research fellow believes that by providing high quality, nutritious feed to broodstock in their pre-maturation stage, shrimp farmers can achieve a similar egg production rate without resorting to eyestalk ablation.
Managing the sex ratio in breeding tanks and increasing the ratio of male-to-female shrimp from 1:1 to 1:2 is another means of achieving the same egg production rate.
Zacarias told the Advocate: ‘Retailers and buyers want the hatcheries to stop using eyestalk ablation. We have to use practices that improve welfare and reduce mortality.’
He will present his work at the GAA’s GOAL conference, to be held virtually this year, from October 5-8.
Delegates will then choose a winner from the three finalists, who include Prairie AquaTech, producer of a microbially enhanced protein ingredient for aquaculture feeds. The third contender will be announced shortly.