Havana, March 21 -- Floating fish cages on La Juventud reservoir in Palacios town, Pinar del Rio province, stand as a testament to the Vietnam - Cuba friendship as Vietnam's tilapia farming technology has transformed this region into a key aquacultural hub, contributing to the Caribbean nation's food security. In 2011, Vietnamese experts introduced the tilapia sex reversal technique to the basic business unit (UEB) of the La Juventud fish farm. By administering male steroid to newly hatched fry, the rate of male fish - which grow faster and attain higher harvest body weight than females - has been raised to 98%. This has become the core technique at intensive farming models. UEB Director Pedro Antonio Gonzalez Graveran said it is the key ...