Art of invasive species

From Bluesky user charlie comes these art pieces of four invasive species, with Marmorkrebs in the middle:

 

 

The other three invasives are apple snails, round gobies, and European water chestnut plants.

Marmorkrebs featured in Indian news article

India Today has a nice little feature on animals that reproduce asexually. I am a little disappointed that marbled crayfish only come in at the middle of the list, but the photo they used is nice.

External links

7 animals that reproduce without mating

SyFy article spreading the word

There’s been an uptick in my Google Alerts because of a new article about Marmorkrebs on SyFy Wire.

 

At first, I though the article was recycled from the big burst of coverage when the marbled crayfish genome was sequenced. A good chunk of the article discusses the 2018 paper, and it uses a press photo that came out at that time.

 

But as I saw back in 2018, when one popular news site does a story, many more will pick it up.

 

Update, 6 July 2022: Ths story got picked up on Yahoo! News. Good time for me to talk about the misleading title.

 

The title - “Cloned crayfish accidentally created in an aquarium are conquering the world” suggests people were actively mucking about with crayfish to accomplish something. No evidence of that.

 

There is zero evidence marbled crayfish were “created” in an aquarium. Again, it suggests human involvement when there was almost certainly none. Triploid (but maybe not reproductive) individuals of the sexual ancestor exist in wild. Early Marmorkrebs may have been collected from the wild and only later got a foothold in the aquarium trade, 

 

External links

 

Cloned crayfish accidentally created in an aquarium are conquering the world

Marmorkrebs at the ready

Spotted on Reddit:

 

 

I always worry if Redditors are okay.

 

External links

 

Weaponized Marmorkrebs! Don't leave home without one.

Fun for people of all ages! Marmorkrebs colouring

I stumbled across a page with a coloring book style blank illustration of Marmorkrebs! While the page says it’s for kids, there’sa a lot of fine detail that makes me think some young ones may find it a little on the high end of the difficulty scale.

 

 

The shape of the claws looks much more like Louisiana red swamp crayfish than Marmorkrebs, though.

Zoobabies, 2021 edition

The Cincinatti Enquirer answers a question I’ve been wondering for a while. 

 

Some years ago, I noted the Cincinatti Zoo had a display of “Marbled crayfish” and listed them as Procambarus fallax. The zoo’s description mentioned nothing about asexual reproduction, so I thought they were slough crayfish from Florida or Georgia.

But a new article about the zoo says:

 

This baby marbled crayfish resembles a small lobster, but it will only grow to 2 to 3 inches long. All marbled crayfish are women. They don't need a partner to reproduce.

 

Marmorkrebs they are, then! Which makes me wonder why their reproduction wasn’t mentioned on the display.

Related posts

 

Zoo babies

 

External links

 

Up close with the Cincinnati Zoo's most adorable ambassadors

Harper’s magazine features Marmorkrebs in Madagscar

Rowan Moore Gerety has just published the best article ever written about Marmorkrebs.

 

“Stowaways” appears in the February 2021 issue of Harper’s magazine. It’s a feature-length examination of the invasion of Marmorkrebs on Madagascar. It was prompted by conversation with Julia Jones and was almost two years in the making.

 

There is some science, but the bulk of the article is a nuanced, detailed examination of the complexities of living with environmental change.

 

Over and over again, people are ambivalent to Marmorkrebs. People recognize the crayfish is a pest... but it’s a cheap meal. In a place where most people are living on the equivalant of a couple of US dollars a day, that matters.

In the hills above town, where rice cultivation depends on rainfall for irrigation, farmers complain that the levees of their terraced paddies spring leaks without warning, sparking arguments when valuable rainwater drains into their neighbors’ fields instead. Most realize that crayfish burrows are to blame, but suspicions linger all the same. “The tsi pe’peo is an enemy of agriculture,” Ramandrosoa told me. Nevertheless, he hesitated to advocate for its eradication. For families without even enough money to pay their children’s school fees, he said, “It’s kerosene, it’s sugar, it’s soap. It’s the basic necessities.” In the lean months, Ramandrosoa explained, “People collect crayfish so they don’t have to sell their rice.”

I also love the illustrations by Barry Falls. Look at this gem:

I’ll forgive that the abdomen probably can’t bend quite that much.

 

I will probably be rereading this many times. It’s a rich and insightful part of a story that I know from the published literature, but this shows just how little of the story makes it into journal articles.

 

Highly recommended.

External links

Gerety RM. 2021. Stowaways. Harper’s 342(2049): 72-79. https://harpers.org/archive/2021/02/stowaways-crayfish-madagascar/

Marmorkrebs and messed-up childhoods

Brian Clegg is promoting his new book, What Do You Think You Are?, which is coming out next week. As part of his promotion, he has an article in i newspaper about what shapes adult life. (Really, the name of the paper is a single lower case letter i.) The thesis of the article is that your parents and school don’t matter much to your adult life.

Somewhat strangely, Marmorkrebs make an appearance to argue for “chaos” in life outcomes. Clegg writes:

Batches of Marmorkrebs were raised in nearly identical environmental conditions, yet they differed widely. Some were 20 times bigger than others. Some lived twice as long. Their behaviour was totally different. The tiny genetic and environmental differences made a huge difference in outcomes.

The claims here seem to be based on Vogt and colleagues (2008), and they deserve a little examination.

The “nearly identical” environment is bit misleading. Vogt and colleagues noted that the most variation in growth came when crayfish were raised together, and “without shelters, i.e. under conditions of social stress” (emphasis added).

It’s like saying Harry Potter and Dudley Dursley were raised in “nearly identical” conditions. Well, yes, they were generally in the same physical space. But the social reality for the two boys could hardly be more different. Dudley is spoiled. Harry is tolerated at best and harassed at worst.

Similarly, crayfish fight and form hierarchies. Just because crayfish were in the same tank and had ample food does not mean that their experience in the Dursley house – I mean, crayfish tank – is necessarily the same. Nor is it accurate to call that a “tiny” environment difference.

“20 times bigger” is a bit ambiguous. I image that people might imagine one crayfish an inch long and another 20 inches (over a foot and a half) long. But the measurements are mass, not length. Since mass increases with the cube of length, that means one crayfish is about 2.5 longer than another.

I am not sure how different behaviour has to be to count as “totally different.” I’ve watched a lot of crayfish. You can tease differences apart in experiment, but I think most people would have a hard time distinguishing the behaviour of one Marmorkrebs from another. It’s not obvious, like the relaxed dog you see chilling in the dog park and the barky aggro dog you have to keep on the leash.

I don’t know if Marmorkrebs also appear in the book. I hope they do but with perhaps a little more nuance than in this short article.

Related posts

How Marmorkrebs can make the world a better place

External links

What makes us ourselves? Why your parents might not f*** you up as much as you think

References

Vogt G, Huber M, Thiemann M, van den Boogaart G, Schmitz OJ, Schubart CD. 2008. Production of different phenotypes from the same genotype in the same environment by developmental variation. The Journal of Experimental Biology 211(4): 510-523. http://jeb.biologists.org/cgi/content/abstract/211/4/510

Marmorkrebs in The Times

This a Jeopardy! style post. The answer is:

17 Marbled crayfish or marmorkrebs (Procambarus virginalis). It makes clones of itself from eggs unfertilised by sperm.

The question is one of twenty in today’s Saturday Quiz in The Times!

External links

The Times Saturday Quiz: May 23, 2020

Mad about Marmorkrebs (mad angry, not mad interested)

A question on Quora popped up: “If Wikipedia is correct, how can people believe the speciation story of the Marbled Cray actually occurred?” I summarized the available science, which prompted this fascinating comment.

That the MC’ has 3 chromosomes, because it had 3 chromosomes when the scientists, (or whoever claimed a speciation occurred), (Your buddies), went to the German village, collected some live MC’s, thereon the person ‘creating’ the sham event, did put baby MC’s into the tank with Slough Cray’s……

It is obvious that Wiki are driven by Evolutionists like yourself, and writing a paper on how your mates say the sham speciation event occurred, is of no consequence to the reality that: The MC was ‘Created” a very long time ago with 3 chromosomes to be capable of self replication, to help feed the people, the German Traders at the Village has already stated to the world, that they were trading the MC’ for generations, hence, the MC’ simply has, and always had 3 chromosomes….

And your “Manufactured” series of events, are simply a stab in the dark, because the MC’ was placed in the tank, and people like you, then Peddle the sales pitch……… That is the TRUTH is it not

The internet is wonderful, because it lets you know what people think.

External links

If Wikipedia is correct, how can people believe the speciation story of the Marbled Cray actually occurred?

Nature, nurture, noise

A new feature by Jordana Cepelewicz in Quanta Magazine starts off using marbled crayfish to make a point about variation:

In the 1990s, an army of clones invaded Germany. Within a decade, they had spread to Italy, Croatia, Slovakia, Hungary, Sweden, France, Japan and Madagascar — wreaking havoc in rivers and lakes, rice paddies and swamps; in waters warm and cold, acidic and basic. The culprits: six-inch-long, lobster-like creatures called marbled crayfish. ...

New research on crayfish and scores of other organisms is revealing an important role for a third, often-overlooked source of variation and diversity — a surprising foundation for what makes us unique that begins in the first days of an embryo’s development: random, intrinsic noise.

Marmorkrebs are not the point of the article, but it’s nice to see them so prominent featured. It’s a nice example of how marbled crayfish can be used as a model for general biological problems.

External links

Nature Versus Nurture? Add ‘Noise’ to the Debate.

Concealed crayfish and The Hidden Half

Marmorkrebs rarely make appearances in pop culture. Based on this summary from the Financial Times, I want to read this.

Michael Blastland’s recent book, The Hidden Half, argues that much of the variation we see in the world around us is essentially mysterious. Mr Blastland’s opening example is the marmorkrebs, a kind of crayfish that reproduces parthenogenetically — that is, marmorkrebs lay eggs without mating and those eggs develop into clones of their mothers.

Place two clones into two identical fish tanks and feed them identical food. These genetically identical creatures raised in apparently identical environments produce genetically identical offspring who nevertheless vary dramatically in their size, form, lifespan, fecundity, and behaviour. Sometimes things turn out very differently for no reason that we can discern. We might as well call that reason “luck” as anything else.

There’s a preview on Good Reads of the first chapter, which includes most of the stuff on Marmorkrebs. I’d like to point out that this is similar in some ways to an older post here on the blog about similarity and variation.


Related posts

How Marmorkrebs can make the world a better place

External links

The Hidden Half (publisher’s site)

Neil Woodford shows it can be hard to tell luck from judgment

Crayfish crimes 2

I mentioned a couple of weeks back that an American man had been convicted for selling and exporting crayfish as pets. Another case came to attention recently. An Australian man was convicted and fined AUD$8,550 for catching the world’s largest freshwater invertebrate, Astacopsis gouldii. The crayfish is threatened and protected by law.

I mention this because protecting invertebrates is hard, and law enforcement on this sort of issue is rare. It’s encouraging to see.

Related posts

Crayfish crimes

External links

Largest ever fine for poaching giant freshwater crayfish

Zoo babies

Marbled crayfish are featured in this year’s Cincinnati Zoo’s Zoo Babies display! The Zoo’s website shows they are part of the display, but no more. I do complement their photographer for the particularly cute crayfish pic (above) on their site.

I reached out to the Zoo, and heard back from Mandy Pritchard, who is the “World of the Insect Team Leader” at the zoo. (Now there’s a great job title.) She was kind enough to send me a couple of pictures of the display:

There’s a very nice shirt available. Unfortunately, it’s doesn’t seem to be available in adult sizes.

Based on the description in the display, I think these are the sexual slough crayfish and not Marmorkrebs. But it’s fun to see crayfish on display nevertheless!

External links

Zoo Babies
The "Amazing" Marbled Crayfish - Youth Garments

The crayfish apocalypse

Of over a hundred news articles, blog posts, and other miscellaneous things I have seen on the Internet about Marmorkrebs since the genome paper came out, this Non Sequiter comic by Wiley may be my favourite of all of them. And that includes articles that quoted me or used my Marmrorkrebs picture.

Click here to read it.

Hat tip to James Murray.

By “invasive species,” do you mean crayfish or Daleks?

When you’re a scientist, sometimes you forget that other people see the world through different lenses than you do. And sometimes you have that point hammered home in no uncertain terms.

Last week, the American White House released an executive order from outgoing President Barack Obama about invasive species.

As someone who has written about invasive species, I thought, “Ho hum, routine sorts of stuff.”

But because I had shown interest in invasive species, Google suggested this page to me:

NO JOKE! Obama signs executive order to ‘Safeguarding the nation from an INVASIVE SPECIES’

Wait, what? Why is this page showing the American president and a SF style alien? My emphasis:

Obama has pushed through an act called “Safeguarding the Nation from the Impacts of Invasive Species.” The interesting thing about this presidential order (see full text below) is the legal wording of the document leaves a lot up for suspicion. The article was left purposely vague, it seems.

There are a few reasons for this. The first could be simply so the article can be interpreted for years to come. The second is a little more malicious and slightly terrifying. An invasive species in the document is vaguely defined as an organism that disrupts an ecosystem. Because of this, some are speculating that this last order of 2016 is meant to protect from alien invasions, and purposely set some guidelines for the next presidency.

It has been shown in the news that the government is getting closer to telling its people what is actually out in space. If the planet needs protection for these beings, it will make sense that they would be motivated to tell the people, and also motivated to write an article to set up pretenses to protect the Earth. This is only my opinion, but I hope that some of my readers will do some investigation. Something strange is happening within the government.

Now I wonder: when I have said, “invasive species,” how often have non-scientists heard, “alien invaders”? It kind of makes sense to me now. Anyone who watches science fiction will probably heave heard aliens described as “difference species.” Indeed, there’s a horror movie franchise whose name plays around with that ambiguity:

But despite that, it never occurred to me that someone might think “species” is synonymous with “extraterrestrial” rather than meaning “type of organism.”

Now, when I write about potential negative impacts of crayfish introductions, I have to think of other phrases to use so that when I say “invasive species,” people don’t automatically leap to this:

Related posts

Crayleks!

External links

Executive Order -- Safeguarding the Nation from the Impacts of Invasive Species
NO JOKE! Obama Signs Executive Order To 'Safeguarding The Nation From An INVASIVE SPECIES'

The two sides of marbled crayfish

The International Association for Astacology meeting was recently held in Spain, and a nice press release about the two major lines of research on Marmorkrebs: as an unwanted invasive, and as a wanted model organism. I draw similar comparisons in my own chapter.

Between Google Translate and a little guesswork, I think the press release reads something like this:

• This North American species is reshaping ecosystems by killing fish or molluscs on the one hand, and on the other hand, is used for studies related to cancer thanks to their particular genetics.
• Researchers Pavel Kozák and Frank J. Lyko presented studies about this crustacean at the 21st International Symposium of Astacology.

The marble crayfish (Procamborus (sic) fallax) is a curious exotic species, as has been disclosed during the 21st International Symposium of Astacology, which takes place at the Royal Botanical CSIC Garden. Like the strange case of Dr. Jekyll and Mr. Hyde, it shows two sides: a positive, because thanks to their particular genetics, it is used for cancer-related studies; and the other less pleasant, because it is an invasive species that is ravaging different ecosystems.

Researchers Pavel Kozák from the Faculty of Fisheries and Protection of Waters of the University of South Bohemia in the Czech Republic, and Frank J. Lyko, from the Cancer Research Center of Heidelberg in Germany, are working on two projects related to marbled crayfish. They presented their studies on this species from the point of view of ecology and reproduction (Kozák) and genetics (Lyko).

According to the Czech researcher, his project initially focused on the impact of invasive species on native species of crayfish, but as the project continued, this deepened to include the interaction between this invasive species and their impact on other invasive species, such as amphibians or fish.

The researcher Kozák focuses on two significant events. “First, marbled crayfish are destroying fish, molluscs, and macroinvertebrates, and ultimately, it is reshaping the entire ecosystem. Second, this invasive species is more powerful than other larger species, thus refuting the claim that the larger species tend to be more aggressive.”

Meanwhile, the German researcher Frank J. Lyko notes that the genetics of marbled crayfish reproduction, i.e., the females create clones of themselves, “is a model species to implement our work on cancer, since there is only one genome to study, hence its importance for medical science.”

Devastating effects

However, Lyko coincides with his Czech colleague Kozák in the “devastating effects” of marbled crayfish, such as in Madagascar where they have destroyed almost all the habitat where they have been, before making the leap to other countries. The first crayfish in Europe were found in Germany in 1995, and by 2010, it was established in nature, especially Central Europe. In the short term, also has changed the habitat of this area.

The two researchers also agree that, given that its eradication is impossible, citizens of the areas where this species is found be educated to know how easily it reproduces and the consequences of their invasion. They also requested legislation regulating the introduction of new species and greater control of ornamental trade, both in physical stores and the sale online, because it is very easy to get this species for aquariums, and their reproduction is immediate and unlimited.

Finally, for Czech researcher Pavel Kozák, this highlighted the work of the Royal Botanic Garden-CSIC of Madrid, which conducts research related to crayfish plague and supports students doing projects on astacology.

When I went to the International Association of Astacology meeting in Missouri in 2010, I think I was one of the first to talk about Marmorkrebs at that venue. At least, several people told me it was news to them. It is nice to see more research at this preeminent crayfish meeting on Marmorkrebs, and making its way into the public.

External links

Cangrejo mármol, una curiosa especie invasora con dos caras (Roughly: Marbled crayfish, a curious invasive species with two faces)

The crayfish / crawfish / crawdad war II

A couple of years ago, some fun dialect maps were making the rounds on the Internet, which I blogged about because one of the questions was about what people call freshwater crustaceans that look like small lobsters.

Those maps were based on the Harvard dialect survey, which ended 2003. This is now being followed by the Cambridge dialect survey, which started 2007, and what people call Astacidea is again one of the questions.

The map is interesting to check out. I think “lobster” looks far more common in the map than in the data, probably because of the layering of the data points.

Interestingly, the gap in use between “crayfish” and “crawfish” widened between the Harvard and Cambridge surveys. But in both surveys, “crayfish” is more northeast, “crawdad” is midwestern, and “crawfish” is southern. I wonder how “fish” metamorphosed into “dad” in the central U.S.

Related posts

The crayfish / crawfish / crawdad war

External links

Harvard survey: Asticidea map
Cambridge survey: Astacidea map

Diversity

The world hotspot for crayfish species, by a long, long way, is the southeastern United States (map from Richman et al. 2015).

The southeastern U.S. is also notable for relatively large populations of African-Americans.

You might think that given the overlap in these two maps, that there would be expertise in the African-American community about crayfish. But I am struggling to think of any African-American scientist who has studied crayfish. Who am I missing?

This also points to crayfish being a great entry point to introduce African-Americans to topics like biology and conservation.

Reference

Richman, NI, Böhm, M, Adams, SB, Alvarez, F, Bergey, EA, Bunn, JJS, Burnham, Q, Cordeiro, J, Coughran, J, Crandall, KA, Dawkins, KL, Distefano, RJ, Doran, NE, Edsman, L, Eversole, AG, Füreder, L, Furse, JM, Gherardi, F, Hamr, P, Holdich, DM, Horwitz, P, Johnston, K, Jones, CM, Jones, JPG, Jones, RL, Jones, TG, Kawai, T, Lawler, S, López-Mejía, M, Miller, RM, Pedraza-Lara, C, Reynolds, JD, Richardson, AMM, Schultz, MB, Schuster, GA, Sibley, PJ, Souty-Grosset, C, Taylor, CA, Thoma, RF, Walls, J, Walsh, TS, Collen, B. 2015. Multiple drivers of decline in the global status of freshwater crayfish (Decapoda: Astacidea). Philosophical Transactions of the Royal Society of London B 370: 20140060.

External link

African-American History Month

Map of African-American distribution from here.

#Marmorkrebs #NoFilter

Here’s a collection of Marmorkrebs pics on popular social media site Instagram. I like scrolling through these pics, because it’s interesting to see the variation in colours or people’s crayfish. But as I’ve written before, make no mistake: if these are Marmorkrebs, their colour is diet and condition dependent. Their offspring won’t necessarily have that colour unless their conditions are similar.

Related posts

The curious case of crustacean colours