Dear Blue Lobster:
I had an arthropod physiology class and in it we discussed Marmokrebs, a crayfish that clones itself. Apparently it is taking over fresh and brackish water systems in Germany and there is fear that it will overrrun Europe unless a way is found to stop it. How is it possible there is a cloning crayfish? I am curious about this topic, many thanks for answering my query.
Dear Gentle Sir:
This crayfish species, named for its marbled shell, has raised debate in astacology recently, as each and every specimen of Marmorkrebs is molecularly identical; that is, each Marmorkrebs is a clone. Its origins are just as mysterious as its genetic pool, with Marmorkrebs only discovered in the Nineties. It still lacks a scientific name until it can be placed within a genus.
Marmorkrebs reproduces in three unique ways, setting it apart from not only other crayfish but all other crustaceans as well. On a regular cycle it goes in berry, holding a clutch of up to one thousand eggs for just over two weeks. The eggs are fertilized although there is no male contact — all Marmorkrebs are also female. The eggs then hatch and the craybies grow just as any other crayfish young.
The Marmorkrebs also buds, where during a series of several molts in the Summer months extra body parts grow and, at the end of the cycle, a completely new Marmorkrebs splits off and lives indepdenently of the original organism. This is a method employed by simpler organisms, including several classes of worms, sponges, and hydras as well as microorganisms like bacteria and fungi.
Analysis of Marmorkrebs DNA reveals several sequences, particularly in genes controlling reproduction, that are unique among Animalia. Research continues in placing Marmorkrebs within crayfish taxonomy, with one Dutch researcher commenting that the DNA is unusual for a crayfish, let alone an arthropod.
Further study will unlock the secrets of this exotic, mysterious new species. In the meantime most Western countries have placed a moratorium on the shipping or sale of the species due to its potential as a nuisance species, though China is investigating it as a cheap foodstuff.