The Amazon molly (Poecilia formosa) is one of the most fascinating fish species. They are all female as they reproduce only by cloning.

In that unusual reproductive process called gynogenesis, the fish still mates with a male from a closely related species like a sailfin molly or Atlantic molly and the sperm penetrates its egg triggering fertilization. However, the sperm’s nucleus and DNA don’t merge with that of the embryo’s. The egg cells proceed multiplying and develop into a female baby while the sperm “dissolves.”

Animals without gene variation risk going extinct for not developing survival traits through DNA mutations, but the Amazon molly defies such a threat because its genome repeatedly rewrites itself or converts genes to erase unfavorable mutations, researchers said in a study of the fish published in the journal Nature on 11 March.

Meanwhile, ordinary fish in the market are not only food but also raw materials for body implants.

A research team in Spain has developed a highly biocompatible artificial cornea using a part of the common market fish, The Standard (TS) reports.

There is a high demand for artificial corneas to replace damaged ones because real ones from human donors are hard to come by, making waiting for one risky to the timely repair of the transparent tissue at the front of the eye, which is responsible for protecting the eyeball and focusing light.

Tissue engineers at the University of Granada and Institute of Biomedical Research have successfully extracted high-quality collagen from the scales of carp to create an artificial corneal implant, according to TS.

Tests of the implant were successful on laboratory animals, with researchers finding that it functions well and doesn’t get rejected by the host. Tests of the implant on humans are still needed to determine its effectiveness and safety.