Hybridisation in aquaculture:
Crayfish aquaculture
In freshwater crayfish aquaculture high densities can result from uncontrolled reproduction. Hence some farmers manually breed yabbies (Cherax albidus) and stock only mate crayfish in farm dams or ponds to counter the reproduction. Although male-only yabby populations produce an estimated 70% increase in gross income, hand breeding is time consuming and is often unreliable. A hybridization experiment using freshwater crayfish from the yabby species complex, collected from geographically isolated regions throughout Australia, revealed a hybrid between Cherax rotundus females and C. albidus males which consistently produces only male offspring. This has been confirmed in nine crosses of the same two species.
This study shows that the use of the all-male offspring produced from hybridising the female freshwater crayfish, Cherax rotundus, and the male, Cherax albidus, offers considerable potential for eliminating the uncontrolled reproduction that occurs in commercial ponds prior to harvest. Here hybridization is used as a mean of control to prevent excess reproduction; an advantage for aqua-cultural farmers.
Issues: Should such techniques be implemented to increase profit or is it unethical?
