Tilapia is a genus of warm predominantly freshwater fish native to Africa. They are robust fish able to withstand high water temperatures and low levels of oxygen. Their optimum temperature range is between 20' to 30'C; they can tolorate temperature as low as 12'c. Many species can withstand salin water up to full seawater. Tilapia species have biological differences associated with their feeding and breeding habits and anotomical differences associated with their feeding habits. These difference have caused systematists to divide tilapia into three genera:
Tilapia, example Tilapia zilli. These spawn in nest which they construct in the pond bottom. They guard the young in the nest. They have coarse teeth and feed on microphytes. Sarotherodon, example Sarotherodon gallilaeus. These take the eggs and larvae and brood them in their mouths. They have fine teeth and feed on particulate matter. Oreochromis, example Oreochromis spilurus. These on the ground but brood the eggs and larvae in the mother's mouth. They have fine teeth and feed on filamentous and unicellular algae.
Tilapia are fast grower under good condition, reaching 150g in weight in ten (10) months. In the wild tilapia can grow to be large fish reaching sizes of 1,300g. Tilapia become sexually matured at an early stage in their delopment when they reach a size of about 15cm general about six months old.
After reaching maturity they spawn every six weeks. This high fecundity of tilapia has cuased the major problem in tilapia farming which is the problem of over-poulation of the pond. That means that food becomes in short supply and fish cannot grow. This in turn means that the farmer when harvets the pond collects a large population of small fish often too small for the market, and, expects in certain places where there is a tradion of eating very small fish, unsuitable for home consumption. Improvements in farming techniques of tilapia have therefore been concentrated in development in farming techniques of tilapia have therefore been concentrated in development ways of overcoming the problem of over-population. Various methods have been developed.
The simplest method is continously to harvest the fish using a selctive sein net so that the largest fish are always removed, thus keeping down the size of the population by removing the market-sized fish. This method is not very effective and is only of limited value in artisanal farms.
For control measure on tilapia population search more on this website.
OTHER POSTS ON AGRICULTURE
Click on the related links below and read more.
We can keep you updated on this information, please Subscribe for
Free by entering your email address in the space provided.
Follows us on Google Plus Facebook & Twitter
Call for help and consultancy on 07030722911