A review on induction of triploidy in fish using heat, pressure and cold shock treatments

Abstract

Induction of triploidy in fishes is widely accepted as the most effective method for producing sterile fish for aquaculture and fisheries management. Triploidy induction refers to the production of individuals with three sets of chromosomes and can be induced in fish by inhibiting the second meiotic division followed by the extrusion of the second polar body by shocking eggs shortly after fertilization using various physical shocks and chemical treatments. Cold shock treatment and heat shock treatment for triploid induction are safe because no chemicals are used. However, these treatments require an optimal treatment temperature to be maintained in a large volume in order to treat a large quantity of eggs. Pressure treatment is also considered to be safe. However, in pressure treatment specific equipments are required and it is usually difficult to treat many eggs on a commercial scale.