In the past, tilapia was considered small and bony, often seen as food for the poor. However, this perception has been changing thanks to the development of monosex tilapia farming models. So, what exactly is monosex tilapia, and what are the effective farming techniques?
Currently, the aquaculture industry is becoming increasingly diversified with many farming models. Among them, the farming of all-male monosex tilapia is gaining attention due to its stable profitability. But do farmers truly understand what monosex tilapia is and how to raise them for higher efficiency? Here is some useful information about monosex tilapia and effective farming techniques.
Tilapia is a special species of fish originally from Africa—one of the earliest fish species cultured in the world. Today, tilapia farming is rapidly developing on an industrial scale in many countries because of its affordable price, delicious taste, sweet and nutty meat, rich minerals, low fat, moderate protein, and its neutral, non-toxic properties, making it good for health.
1. WHAT IS MONOSEX TILAPIA?
Monosex tilapia refers to fish populations that consist of only one sex, usually all-male, with no or very few females.
The body of monosex tilapia often appears slightly purple, with shiny scales and 9–12 dark parallel stripes running from the back down to the belly.
The caudal fin (tail fin) has distinct dark stripes running parallel from top to bottom and distributed across the fin. The dorsal fin (back fin) has white stripes running parallel over a dark gray background. The edge of the dorsal and caudal fins has a light pink hue.
Image of Monosex tilapia
These fish are raised in ponds, lakes, or cages entirely as males, allowing uniform growth without time wasted on reproduction. As a result, tilapia yield and quality are superior, leading to higher economic efficiency.
2. WHY RAISE MONOSEX TILAPIA?
Through observation, farmers have found that male tilapia grow faster than females because the nutrients they absorb are directed toward growth. Female tilapia, on the other hand, allocate energy for reproduction, carrying and incubating eggs. During incubation, female tilapia often stop feeding, which affects meat quality. Moreover, tilapia reproduce multiple times per year.
Since male fish do not use nutrients for reproduction, farming all-male monosex tilapia leads to uniform sizes, higher productivity, and better meat quality.
Image of juvenile tilapia
3. EVEN WHEN STOCKING MONOSEX TILAPIA, WHY DO THEY STILL REPRODUCE?
There are two common methods to “sex-reverse” tilapia:
– Using hormones
– Genetic methods
Image of tilapia breeding
However, both methods achieve only about 95% success and cannot guarantee absolute results, so occasional reproduction still happens.
The main reason is that the sex reversal process requires precise techniques, and environmental factors may significantly influence success. When administering hormones, factors like egg handling and water quality may impact the sex reversal process, making 100% success impossible.
Typically, about 1–5% of females remain; some may become infertile, but others can still reproduce. Under warm conditions, after just three months, they may spawn. Fortunately, the number of offspring produced is relatively small compared to the harvested fish.
It’s important to note that all-male tilapia grow faster than females from the fourth month onward. Therefore, farming tilapia for meat weights above 400g yields higher productivity and better meat ratios.
Monosex tilapia, in particular, grow fast, are easy to raise, and are generally disease resistant. They are often polycultured with other fish species to utilize available feed sources and improve economic efficiency. However, there are important considerations:
+ Choose healthy, disease-free fry from reputable hatcheries with a high male rate for better performance.
+ Use clean water sources free from contamination; disinfect water if needed using A BEZACID 800.
+ Use disease-free feed: Avoid moldy, low-quality feeds or plants collected from areas with high disease risk.
+ Eliminate pathogens in ponds before stocking by thoroughly cleaning and disinfecting the pond.
+ Properly monitor and manage water quality factors (dissolved oxygen, pH, H2S, etc.) and sudden changes to respond promptly. Periodically disinfect ponds with A BENZACID 800 to kill bacteria, viruses, and other pathogens.
+ Regularly observe fish activity, especially during two critical periods: morning (4–6 am) and afternoon (2–4 pm), to quickly detect and address any abnormal signs.
+ During seasonal changes or sudden weather fluctuations, fish may experience stress, giving pathogens a chance to infect. Prevent diseases by using antibiotics; for example, A-ERYCIN 500S or A-OXYLINE 200S. At the same time, supplement A VITA C MAX and A GLU DC from VB Pharma by mixing them into feed for 7–10 days to boost immunity and reduce stress, supporting better growth.
With the above knowledge about monosex tilapia, farmers now have a clearer understanding of this species and have learned key techniques to achieve higher profitability from monosex tilapia farming.