Nile tilapia is the 4th most cultured species of fish on the planet with 5 million tons being produced globally each year. This species is a maternal mouthbrooder; the male makes a nest into which he attracts a willing mate. The pair swim around each other with the female laying subsequent clutches of eggs and the male fertilising them. Once the female has released all the eggs she will spawn on that occasion she is chased out of the nest by the male who resumes courtship with the next potential candidate. The female broods the eggs in her mouth during incubation, and once they hatch she continues to nurture them in her mouth.
Given that the female protects and rears the eggs, reducing natural mortality, why would we consider spawning them any other way?
Tilapia farmers employ primarily one of two methods to obtain fry. The first method involves simply harvesting fry that are released into the breeding tank by the females. As adult tilapia are not cannibalistic this can be done, but it produces very few fry per female and has a number of additional associated problems, including cannibalism by fingerlings in the tank that were not harvested, increased size differentiation, lack of spawning synchrony, and longer recovery time per female following spawning. As a result serious commercial tilapia farmers generally strip the eggs from their females every 5 to 7 days and hatch them artificially. This prevents the females wasting energy on incubation and gets them back to full feeding sooner, both resulting in a shorter inter-spawning interval and more eggs per female per season.
So the primary benefits of artificial incubation of tilapia eggs include shorter time interval between spawns, less size difference per batch and more eggs per group of females in a given time period. Given these distinct advantages to artificial incubation of tilapia eggs this is the standard practice in commercial tilapia farming.
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