By Rafael D. Guerrero III
My father, Rafael Jr., was a lawyer and geodetic engineer in Bacolod City. He inherited a 7-hectare fish farm in San Enrique, Negros Occidental from his mother. On weekends, he would visit the farm where he enjoyed eating young coconuts (buko) and fresh fish and shrimps from the ponds with his family.
In the 1990s, I introduced to my father’s farm the technology for the brackish water pond culture of sex-reversed tilapia hybrid. The male of the Mozambique tilapia (Oreochromis mossambicus) was cross-bred with the female Nile tilapia (Oreochromis niloticus) to produce a hybrid tilapia which was salt-tolerant and had good growth rate due to characteristics inherited from its parents. Being sex-reversed, it had a high percentage of males that minimized its reproduction in ponds and made it grow faster and bigger.
The breeders were stocked in the breeding pond at a sex ratio of three females to one male. The hybrid fry produced were collected and transferred to net enclosures (hapas) in the nursery pond for the 3-week sex reversal treatment using the hormone-feed of Aquatic Biosystems (“The Home of Tilapia Sex Reversal”) in Bay, Laguna. The sex-reversed hybrid fingerlings were sold to brackish water pond farmers.
My father’s fish farm was the first to commercially produce sexreversed tilapia hybrid fingerlings in the province, and perhaps in the region. To meet the demand, my cousin, Rafael Cornejo, who operated a fish farm nearby, adopted the introduced tilapia culture technology.
With the help of my geodetic engineer brother, Eduardo, my father also ventured into milkfish farming, applying the modular method of culture. In the method, the fingerlings are first stocked at 5,000/ha in a transition pond that has been previously prepared for “lablab” (a pond bottom natural food of milkfish) production with fertilization. After two months of culture, the fish were made to transfer to the final growing ponds (also prepared for “lablab” production) at a stocking rate of 2,500/ha and grown for another two months until their harvest. Compared to the traditional method of growing the fish in only one pond from stocking of the fingerlings till harvest, the modular method made the fish grow faster and bigger because of more available “lablab” in the ponds.
My father passed away in 2014. He left us with the legacy of being an impeccable professional and an ardent “gentleman-fish farmer.”
This appeared in Agriculture Monthly’s September 2019 issue.