
The marbled crayfish is a mutant species that clones itself - sohkamyung
https://www.nytimes.com/2018/02/05/science/mutant-crayfish-clones-europe.html
======
diego_moita
If I understand this correctly, asexual reproduction in plants is called
apomixis[0] and the dandelions and blackberries have been doing it for
millions of years.

In animals it is called parthenogenesis and happens in lizards, snakes, birds
and sharks[1]. All of them have been around quite some time on earth, also.

What helped these species to be so resilient to a devastating infection when
other animals that reproduce sexually (Central American frogs, North American
bats) are being wiped away so badly by fungal infections?

[0]
[https://en.wikipedia.org/wiki/Apomixis](https://en.wikipedia.org/wiki/Apomixis)

[1]
[https://en.wikipedia.org/wiki/Parthenogenesis#Natural_occurr...](https://en.wikipedia.org/wiki/Parthenogenesis#Natural_occurrence)

~~~
icegreentea2
It could literally just be time and luck.

We started mass production (cloning) of cavendish bananas around the the
1900s, and REALLY started mass production (cloning) in the 1950s, we only
started seeing strains of banana blight effect it in the last few decades.
Obviously there are all sorts of differences between these cases, but it's
probably worth thinking about a bit.

Oh, also it looks like most animals capable of parthenogenesis can also under
go sexual reproduction, helping them hedge against certain types of threats.

Also remember that we're looking at animal population on human generation
timescales. One might say that a species with a population of millions being
wiped out to a population of thousands (that are fungal resistant) over a time
scale of 60 years as a 'disaster'. It in our life time it probably is, cause
our activities would probably completely fuck over whatever is left. But in
the absense of our activity, those thousands or so could still form a viable
population and if they still have a good ecological niche to occupy, could
easily within a few hundred/thousand years regain their original population.
And we'd be all completely blind to that, cause that's not how we tend to
think.

~~~
IncRnd
> _we only started seeing strains of banana blight effect it in the last few
> decades. ... it 's probably worth thinking about a bit._

It was likely an oversight to not mention why we started to clone the
Cavendish.

Panama disease devastated the also cloned Gros Michel cultivar over 60 years
ago. That's why, today, we eat a different banana than those who came before
us.

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okket
It's «Marmorkrebs» not »Marmokrebs». From Marmor -> Marble. Also, a simple
Google/Wikipedia search should have been possible, dear NYT :(

[https://de.wikipedia.org/wiki/Marmorkrebs](https://de.wikipedia.org/wiki/Marmorkrebs)

~~~
sohkamyung
I've sent a tweet to the author and NYTimes about this. Hopefully they'll
correct it.

~~~
ComodoHacker
They did.

------
pixl97
>Only 1 in 10,000 species reproduce by clones.

When you see a statistic like that it points to a filtering event in a
species. Much like the previous type of banana was clones, once a disease
rises up that attacks that type of clone there just isn't the genetic
diversity and rate of change to save the species.

~~~
danimal88
I dunno, given the number of bugs alone, a statistic like that strikes me as
just numerical drama.

------
Triesault
The explanation is found halfway through the article.

> Normal sex cells contain a single copy of each chromosome. But the mutant
> crayfish sex cell had two.

> Somehow the two sex cells fused and produced a female crayfish embryo with
> three copies of each chromosome instead of the normal two. Somehow, too, the
> new crayfish didn’t suffer any deformities as a result of all that extra
> DNA.

> It grew and thrived. But instead of reproducing sexually, the first marbled
> crayfish was able to induce her own eggs to start dividing into embryos. The
> offspring, all females, inherited identical copies of her three sets of
> chromosomes. They were clones.

> Now that their chromosomes were mismatched with those of slough crayfish,
> they could no longer produce viable offspring. Male slough crayfish will
> readily mate with the marbled crayfish, but they never father any of the
> offspring.

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chriskanan
Supposedly they taste good and part of their spread is intentional. See the
bottom of this article:
[https://www.nature.com/articles/d41586-018-01624-y?utm_sourc...](https://www.nature.com/articles/d41586-018-01624-y?utm_source=fbk_nnc&utm_medium=social&utm_campaign=naturenews&sf181403583=1)

~~~
dr_zoidberg
I was thinking about a culinary solution to this problem. They could even be
farmed, considering their numerous offspring.

~~~
tritium
Seems like an ideal protein source for space travel. Even if the genomic
monoculture represents a serious starvation hazard.

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gboudrias
This is absolutely mind-blowing.

Also, since humans are now very numerous and so good at surviving, makes you
wonder if humans could mutate this way too. Makes it seem like you'd just get
outright pregnant instead of ovulating, which may be a bummer.

~~~
dmix
The article ends by explaining why asexual cloning is a bad idea in the long
term and how few species exist like this, outside of some relatively new ones,
because they lack the evolutionary benefit of sexual adaptation (such as
fighting diseases and other evolutionary traits).

I guess technology and modern medicine could counteract that but it's still
not ideal in the long-term. Nor would genetic clones create a very interesting
society.

~~~
sohkamyung
> Nor would genetic clones create a very interesting society.

One of the more interesting attempts at creating a human society made up of
clones is the James Tiptree, Jr. story, "Houston, Houston, Do You Read?" [1]

[1]
[https://en.wikipedia.org/wiki/Houston%2C_Houston%2C_Do_You_R...](https://en.wikipedia.org/wiki/Houston%2C_Houston%2C_Do_You_Read%3F)

~~~
RepressedEmu
Theres also an Outer Limits episode of a guy trapped on another planet who
self replicates clones of himself. Although I think it does it more through
"splitting" than an actual birth cycle. Very freaky episode with lots of
"body-horror" as he begins to split.

------
im3w1l
Could it somehow mutate again in a way that makes it able to reproduce
sexually?

~~~
tzakrajs
Good idea, I was thinking it would be interesting if the species could turn
asexuality on and off as conditions required.

------
singularity2001
Mistranslation: "German Cancer Research Center" should be "German Crabs
Research Center"?

~~~
MandieD
"Cancer" is the right English translation in this case - the German original
is "Deutsches Krebsforschungszentrum". A center dedicated to studying
crustaeceans would probably be called "Krebstiereforschungszentrum" ("Crab-
animals" research center).

"Krebs" means either cancer (the diseases) or crabs (the animals). The tumors
that early physicians saw reminded them of crabs, so that's what they called
them. English forked cancer (Latin word for crabs) to mean the diseases and
uses the evolved colloquial word for the animals, but German uses its evolved
colloquial word for both. "Krebstiere" is often used to refer to crabs as a
group, probably to avoid misunderstandings.

Prof. Dr. Lyko seems to primarily study epigenetics, and it's just coincidence
that the animals he's studied here are crabs:
[http://www.dkfz.de/en/epigenetik/](http://www.dkfz.de/en/epigenetik/)

------
jimmywanger
One way to get rid of this problem is if they taste good, market them to Asian
restaurants.

Right now spicy crawfish boils are fashionable in China, and I'm pretty sure
the other East/Southeast Asian countries like crawfish also.

Just like with jellyfish. Chinese people already eat jellyfish, so if there's
an infestation of jellyfish in the ocean, figure out a way to eat that
species. A billion people can really put a dent in any wild population.

~~~
bambax
In France they are an invasive species. We are eating it (it can be found on
sale everywhere) but it's not very good.

We have been eating crayfish for a long time; indigenous French (or European?)
crayfish were delicious but they have been wiped out by this species.

~~~
coroxout
In the UK the native crayfish are already severely threatened by invasive
signal crayfish. I'm not sure if we have marble crayfish yet but if they breed
that quickly it sounds very bad for the native crayfish - and maybe for the
accidentally introduced signal crayfish too.

There are various streams near me where you can go out in summer with a piece
of bacon, some string and a box (maybe a net too) and catch signal crayfish.
You don't need a permit as they're an invasive species - in fact you're not
allowed to put them back if you catch any.

(But do put them back if you catch the native species! The signal crayfish are
larger and have big red claws with white flashes which give them their name.)

edit: was writing my now largely redundant post as masklinn posted. I hadn't
realised the Marmorkrebs were smaller - does that make them less of a threat?
It does say they're already a problem for native species in Madagascar.

~~~
robthebrew
I'm off to buy bacon right now! Any particular streams? Slow/fast moving? Mind
you, given the temperature it might be more like ice fishing.

~~~
coroxout
It appears I was mistaken and you do need a licence, though it's free. You
should also ask the landowner's permission.

I had thought you only needed the licence to set up traps, which I'd rather
not myself as there's a risk of catching/injuring/killing other species,
particularly native crayfish or otters. Sorry for the inaccurate post. Sadly
it's too late to edit it or I'd put strikethrough all over it...

More details about catching (mostly with traps) and licence details below.
[http://foragedfoods.co.uk/how-to-catch-signal-
crayfish/](http://foragedfoods.co.uk/how-to-catch-signal-crayfish/)
[https://www.gov.uk/guidance/permission-to-trap-crayfish-
eels...](https://www.gov.uk/guidance/permission-to-trap-crayfish-eels-elvers-
salmon-and-sea-trout#crayfish-trap-authorisation)

To answer your questions, I'd wait until at least spring; I've only been in
summer. Not sure about speed or depth (I've seen them in fast shallow streams
and in a slower metre-deep river) but they like lots of hiding places like
rocks or overhangs.

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fulafel
Is "mutant" here used to invoke comic book imagery, or is there some meaning
in science writing to "mutant species"?

~~~
xbmcuser
Mutant is a scientific term taken over by comics it means something changed in
the gene that made it different from others. Mutants are actually quite common
in the animal kingdom but usually die out as they can rarely reproduce if they
reproduce they become a seperate and unique species the difference with this
crayfish is that it is reproducing on its own. We are all descendents of
mutants that seperated into homospaiens.

~~~
iskander
>Mutants are actually quite common in the animal kingdom but usually die out

Naw, every person is likely to carry at least one de novo mutation in their
genome. Mutations happen constantly, they're just usually unremarkable.

~~~
fulafel
Hence the pondering about the meaning of "mutant species".

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m3kw9
Very well written article to capture your attention on a subject that isn’t
really unique

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frozenport
Missing from the article is that unlike most self-cloning animals (I know of
no other), Marmorkrebs, has a triploid genome.

