Tagged: marbled crayfish

Cloned crayfish swarm conquers Europe
… and moves on to the rest of the world!
OK, this is seriously weirder than the mad science plot. Science Magazine reports that a hybridization event among slough crayfish (native to North America) resulted in a triploid strain appearing, all female and reproducing by self-cloning.
Triploid! You all have two copies of every gene, one inherited from your mother and one from your father. There are exceptions, e.g. people with Down syndrome have three copies of all or part of one chromosome. The marbled crayfish is the super-powered version: it has three copies of its entire genome, two near-identical copies (presumably from one ancestral clone-parent) and one of another proto-parental genome.
It’s the only known decapod crustacean to reproduce asexually. It does it fast, it’s displacing other organisms all over the place.
It may not be obvious to a non-biologist how deeply weird this is. Polyploidy (having more than two copies of each gene) is common in higher plants, but it’s very, very rare in animals, and this speciation event happened in the 1980s, so very recently.
The Science article is very readable, and if you’re interested I recommend it.