Posted on 02/05/2018 2:08:22 PM PST by BenLurkin
The marbled crayfish is the only crustacean that reproduces asexually, with the all-female species making clones of itself from eggs unfertilized by sperm...
Since its discovery in 1995 in Germany, the marbled crayfish has spread across Europe and into Africa in huge numbers. “They eat anything—rotten leaves, snails or fish broods, small fish, small insects," says Frank Lyko, a molecular geneticist at the German Cancer Research Center in Heidelberg. “This crayfish is a serious pest,”
...
Lyko and his colleagues sequenced genomes of about a dozen marbled crayfish from different parts of the world and performed less detailed genetic analyses of two dozen more from across Madagascar. At 3.5 billion DNA bases in length, the crustacean’s genome is bigger than the human genome, but contains about the same number of genes, 21,000, they report today in Nature Ecology & Evolution.
...
As suggested by some preliminary evidence, the marbled crayfish has three sets of 92 chromosomes, not the usual two, and each set is essentially a version of the chromosomes belonging to the slough crayfish (P. fallax). Two of the three sets of chromosomes are virtually identical, but the third is different enough that Lyko’s team concludes the marbled crayfish likely arose from the mating of two slough crayfish from different regions of the world thrown together in an aquarium. One must have had an abnormal egg or sperm that retained two copies of its chromosomes instead of the usual single set that is in such germ cells, Lyko explains. The bringing together of the two distant slough crayfish enhanced the genetic variation within the new clonal “species.” Such a union “would never happen in the wild,” he asserts.
(Excerpt) Read more at sciencemag.org ...
*** “Being clones, I expect they all taste the same” ***
Post of the Thread!
The story, in Omni Magazine, scared me as a 13 year old!
Note: this topic is from . Thanks BenLurkin.
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