The first bisexual shark caught a net of Taiwanese fishermen

The extremely rare bisexual shark caught by Taiwanese fishermen can be explained in this species.

The Pacific spadenose shark caught by Taiwanese fishermen in January this year is only 0.5 meters long and weighs 0.4kg, according to Hakai Magazine. This specimen is one of the few bisexual sharks ever found.

Although many species and sharks develop male or female genital organs permanently before birth, making bisexual sharks become very rare. Researchers know very little about the reproduction of sharks, but they think that bisexual status can explain why some sharks have asexual reproduction capacity."Sharks can give birth without mating, like a virgin. The question is why?" , Dr. Chris Lowe of the University of California, Long Beach, said. "We do not know enough about the biological characteristics of sharks enough to answer this question."

Bisexual sharks are very rare.(Artwork: Cultura RM).

The bisexual shark got caught in the dredging net south of the Taiwan Strait, and was pulled ashore in Xiamen, China. At first, it looked like an adult male with a pair of extra organs that developed a penis called a lobe , extending from the ventral fin. But when studying inside the body, scientists found it had two complete bisexual sex glands, containing both ovarian and testicular tissue. This means the animal has both male and female genitalia.

The research team at Xiamen University found that every shark's genitals have developed completely, so animals can act as males or females when spawning. This is the most rare type of hermaphrodite in sharks, because most cases of genitalia are only partially formed.

According to Dr. Carl Meyer, marine biologist at the University of Hawaii, these bisexual sharks are extremely rare. Dr. Meyer said the researchers could not confirm whether bisexual sharks were able to effectively use both male and female genitalia to reproduce. They have never found a bisexual shark carrying embryos living in the womb.

Some scholars speculate that bisexual sharks can be a human result. Recent studies look at the increasing bisexual characteristics of fish in the US, a phenomenon that may be associated with the existence of estrogen and many other hormones in the country.

"Environmental pollution is certainly not the only reason for this phenomenon. Genetic factors can determine what happens during reproductive development. A genetic mutation can lead to for example, the duality is extremely rare in one species, " said Dr. Meyer.