🦞 One Becomes Billions: The All-Female Crayfish Cloning Its Way Around the World
Warning: If you have one of these in your fish tank, do not release it into nearby water.
A bizarre species of crayfish is rapidly multiplying and it doesn’t need males to do it. The marbled crayfish (Procambarus virginalis) is an all-female species that reproduces through parthenogenesis, a rare form of asexual reproduction where eggs develop without being fertilized.
Reproduction on Repeat
Each marbled crayfish can lay 20 to 50 eggs every month, and every daughter is born fully capable of doing the same once she reaches six months of age. Because all offspring are genetically identical to their mother, a single crayfish can start an unstoppable chain of self-cloning, leading to exponential population growth. What’s alarming is that, while researching these crayfish, I found countless photos of them being raised as pets. Imagine how quickly a tank could become overrun!
From Pet Tanks to Global Invaders
First discovered in the German pet trade in the 1990s, scientists believe the species originated from a mutation in the slough crayfish (Procambarus fallax). Since then, it has spread across Europe, Asia, and Africa, particularly overwhelming freshwater ecosystems in Madagascar, where it's displacing native species and altering biodiversity.With no need for males, fast reproduction, and clones that adapt well to different environments, marbled crayfish have become a serious invasive species. The European Union has banned their sale and release in an attempt to slow their spread.
Sources:
* https://www.bbc.com/news/world-43032061
* https://canadiangeographic.ca/.../attack-of-the-clones.../