FEB 06, 2018 10:55 AM PST

Mutant Crayfish, Ready for Takeover

WRITTEN BY: Carmen Leitch

What was probably an accident at a pet store has perhaps led us to the plot of a terrible movie: mutant crayfish are poised for world domination. After being created roughly two decades ago, they have spread across Europe and even to Africa, wreaking havoc on native species and ecosystems. 

It is suspected that around 1995, a reproductive mistake led to the development of an invasive species. Two slough crayfish imported from Florida to Germany were mated. It was suspected that the mating produced an animal with three sets of 92 chromosomes instead of the usual two. One parent may have contributed an unusual egg or sperm with the extra chromosome, allowing the pairing to create a new species. Some scientists have suggested that this coupling could have occurred in the wild though; we have no real way to know precisely when or how it happened. 

One of the only crayfish species that can reproduce asexually, this female marbled crayfish makes clones of itself from unfertilized eggs. Analysis of progeny taken from all over the globe has indicated that indeed, they are all clones of each other. It took fifteen years for scientists to piece together the genome of the marbled crayfish; it was confirmed that it evolved from Procambarus fallax, or slough crayfish originating in the Satilla River in Florida and Georgia.

 "It is mere speculation that it originated in captivity," said Gerhard Scholtz, an evolutionary biologist at Humboldt University in Berlin who has tracked them around the globe. Genomic analysis of marbled crayfish DNA from across Europe and Africa "shows that all these crayfish are clones - with identical genomes the world over," he added.

Putting the origin of the species aside, it can survive in many places. Usually being a clone would be assumed to be a disadvantage; there is often little room for adaptability for such an animal. But, this crayfish is thriving in many different conditions with varied temperatures, acidities, and salinities. 

Marbled Crayfish fry about two days old. Image taken with a handheld microscope. / Credit: Wikimedia Commons/J-P Despault

"This paper suggests that an animal species can rapidly invade a large geographical area despite reproducing without sex and being clonal," Etienne Danchin, an evolutionary biologist at the National Institute of Agricultural Research in Sophia-Antipolis, France told Science News.

It could be that the third chromosome is a big help to this invader. These crayfish have been found in many places, including Japan and Madagascar, where they are posing a major threat to native species. Time will tell how far they go, and how long the species survives. 

"Maybe they just survive for 100,000 years," commented Frank Lyko, a molecular geneticist at the German Cancer Research Center in Heidelberg, who has been studying the crayfish for years. "That would be a long time for me personally, but in evolution, it would just be a blip on the radar."

Sources: Science News, IB Times

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 03, 2018
Cell & Molecular Biology
SEP 03, 2018
Predicting the Impact of Gene Splicing Errors
Researchers are beginning to learn more about how gene mutations that affect RNA splicing are connected to health problems....
SEP 10, 2018
Genetics & Genomics
SEP 10, 2018
In Autism, Background Mutations can Impact Disease Severity
While people are made from the same genes, small changes in those genes can have an impact on our biology....
SEP 27, 2018
Genetics & Genomics
SEP 27, 2018
Learning What Causes Algae Blooms to Turn Toxic
According to the EPA, algal blooms threaten every state and in our changing climate, they may be more common....
OCT 21, 2018
Genetics & Genomics
OCT 21, 2018
The Genetic Cause of Severe Childhood Epilepsy is Revealed
This work has opened up new therapeutic avenues that the scientists will be exploring....
OCT 24, 2018
Neuroscience
OCT 24, 2018
Self-Restraint And Will Power Improves Weight-Loss: Scientific Evidence
Weight loss success linked with active self-control regions of the brain...
NOV 12, 2018
Microbiology
NOV 12, 2018
Some Bacteria Gain Resistance Even Without Exposure to Antibiotics
Most bacteria are harmless, some are even beneficial to us. But some of the dangerous ones pose a real threat to public health....
Loading Comments...