Scientists Have Sequenced The DNA Of An All-Female Species Of Fish Species

The Amazon Molly lives in fresh water streams near the Texas-Mexico border.

By Rhonda FanningFebruary 14, 2018 7:06 am

In Greek mythology the Amazons were an all-female group of fierce warriors who lived near the Black Sea. For thousands of years, that legend has inspired works of art and volumes of literature. But today, and in waters a little closer to home, the word Amazon describes a fish. Commonly known as the Amazon Molly, this all-female species of freshwater fish flourishes along the Texas-Mexico border. Recently, researchers succeeded in sequencing the Amazon Molly genome for the first time.

Manfred Schartl, an advanced study faculty fellow at Texas A&M’s Hagler Institute, led the international team that sequenced the Amazon Molly’s genome.

Despite the fact that all Amazon Molly are female, the species can reproduce.

“These fish can be all female because the do not reproduce sexually like most other species,” Schartle says, “The eggs can start to produce an embryo without the male genetic material.”

Schartle says that Amazon Molly have existed for over 500,000 generations. Their genetic structure does not show the degradation most biologists would predict for a species whose offspring are clones of the mother.  

“This [lack of degradation] was a surprise,” Schartle says. “The big question was, ‘if they are so good, why are they so rare?’”

Written by Christopher De Los Santos.