Sawfish Resorts to Parthenogenesis for Reproduction
Researchers from the Florida Fish and Wildlife Conservation Commission have for the first time identified parthenogenesis phenomenon in a vertebrate in the wild. They have discovered a critically endangered species of sawfish that uses the technique of ‘virgin births’ for reproduction. Researchers asserted that smalltooth sawfish numbers are so low that mating opportunities may not exist for them.
Scientists cited this unusual behaviour to overfishing and habitat destruction which has moved them closer to the brink of extinction. Marine biologist Andrew Fields from Stony Brook University said that similar cases have been recorded in reptiles, birds and sharks. This, he said, has raised questions about how common the technique of ‘virgin births’ among the wild in captivity is.
Parthenogenesis is a technique in which a female’s egg cell develops into a baby without being fertilised by a male sperm cell. This happens when a precursor cell divides into four cells before forming an egg cell. The cell which transforms into an egg cell retains cellular structure and gel like cytoplasm while the other three hold extra genetic material. One of these cells then acts as a sperm and fuses with the egg. The fertilized egg possess about half the mother’s genetic diversity.
In the research, scientists discovered seven healthy sawfish; about 3 percent that were born through parthenogenesis.