Many fish species may become extinct due to gender imbalance

In some species of scaly oceans, the temperature determines the sex of the fetus. A series of experiments by two Spanish scientists showed that the higher the temperature, the more likely the fetus to become male.

"For species whose sex is determined by temperature, normally the ratio of males - females is 1: 1, but as long as the domestic temperature rises to 1.5 degrees Celsius, this ratio becomes 3: 1, " said biology professor Francesc Piferrer of the Spanish Scientific Research Council.

Francesc said, 98% of small white fish in South America will be male if the temperature in the water increases by 4 degrees C.

The temperature determines the sex of about 5,000 marine fish species.
Photo: seasky.org.

The International Committee on Climate Change (IPCC) predicts that ocean temperatures will increase by at least 1.5 degrees Celsius this century. According to Francesc, if the ocean temperatures rise by up to 4 degrees Celsius and the fish are not able to adapt, many species will face the risk of extinction because there are no females.

Much of the research on fish's sex-making mechanism is done in the laboratory, but small white fish is one of the few species that scientists can study right in their habitat. At the present time, no one has confirmed that the increase in temperature reduces the number of fish throughout the planet. Of the 33,000 species of fish, only 5,000 species whose environmental temperature determines the sex of the fetus.