28 July 2020

Marmorkrebs and messed-up childhoods

"What Do You Think You Are?" cover
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


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

15 July 2020

Map of Marmorkrebs introductions, now with Austria!

Map of Europe highlighting Austria
I made multiple additions to the big map of Marmorkrebs introductions. The biggest change is the addition of Austria to the list of countries with established Marmorkrebs populations.

The discovery of Marmorkrebs in Salzburg, Austria was published back in 2018 (Latzer and Pekny 2018), but I only just caught up to it today.

Trying to understand that paper (since it was in German) led me to another short abstract describing another Marmorkrebs finding in Austria, this time in Vienna (Moog et al. 2019). This description is brief, so the map position is not precise:

According to Thomas Ofenböck (Municipal Department 45 - Water Management), in August 2018 a single specimen was found in the 22nd district and released in the Mühlwasser.

Released? Oh, that hurts to read.

Finally, I have a more precise position for the location where Marmorkrebs were found in France. Previously, I only had a description of the area from Marc Collas’s tweet. Again, I stumbled upon a much lengthier description of the finding (Collas 2019), which included a map. That allowed me to get a more exact position.

And just to round things out, I added a couple more of sites from Hungary mentioned in Szendőfi and colleagues (2018).

Busy day. Wish I had done this before this year!

References

Collas M. 2019. Premier signalement de l’écrevisse marbrée (Procambarus virginalis) en Centre de ressources espèces exotiques envahissantes. http://especes-exotiques-envahissantes.fr/premier-signalement-de-lecrevisse-marbree-procambarus-virginalis-en-france/

Latzer D, Pekny R. 2018. Erstnachweis des Marmorkrebses für Österreich in Salzburg. Salzburgs Fischerei 49(3): 24-30. https://issuu.com/lfvs/docs/safisch_3-18

Moog O, Leitner P, Huber T, W. R, Graf W. 2019. Marbled Crayfish (Procambarus virginalis Lykow, (sic) 2017) – a supplement to the list of Aquatic Invertebrate Neozoa in Austria. ECOPROF. https://www.ecoprof.at/index.php/faunaaquaticaaustriaca.html?file=files/ep_downloads/faa/New_Neozoon_Marbled%20Crayfish.pdf

Szendőfi B, Bérces S, Csányi B, Gábris V, Gál B, Gönye Z, Répás E, Seprős R, B. T, Kouba A, Patoka J, Weiperth A. 2018. Egzotikus halfajok és decapodák a Barát‐ és Dera‐patakban, valamint a torkolatuk dunai élőhelyein. Pisces Hungarici 12: 47-51. http://www.haltanitarsasag.hu/ph12/Szendofi_et.al_Pisces.Hungarici_2018.pdf

Collas, 2019

Collas M. 2019. Premier signalement de l’écrevisse marbrée (Procambarus virginalis) en France.   Centre de ressources espèces exotiques envahissantes. http://especes-exotiques-envahissantes.fr/premier-signalement-de-lecrevisse-marbree-procambarus-virginalis-en-france/

(Approximate English translation of title: First report of the marbled crayfish (Procambarus virginalis) in France)

Abstract

Without abstract. Translated excerpt: 

Following surveys carried out by the Moselle fishing federation, P. virginalis has just been reported for the first time in a natural environment in France, in a body of water in the context of ballast pits on the Moselle catchment area, near Metz. This morphological identification was confirmed by molecular analysis using a mitochondrial gene.

Keywords: None provided.

Moog and colleagues, 2019

ECOPROF logo
Moog O, Leitner P, Huber T, W. R, Graf W. 2019. Marbled Crayfish (Procambarus virginalis Lykow, (sic) 2017) – a supplement to the list of Aquatic Invertebrate Neozoa in Austria. ECOPROF. https://www.ecoprof.at/index.php/faunaaquaticaaustriaca.html?file=files/ep_downloads/faa/New_Neozoon_Marbled%20Crayfish.pdf

Abstract

The marbled crayfish (Procambarus virginalis Lykow (sic), 2017) is added to the list of aquatic invertebrate neozoa in Austria. The scientifically proven first evidence of marbled crayfish in Austria took place in June 2018 and was published by Latzer & Pekny (2018). The occurrence of the marbled crayfish is so far known only from two ponds in Salzburg (Karlsbader Weiher and pond FBZ I/135; Latzer & Pekny, 2018) and one finding in Vienna. According to Thomas Ofenböck (Municipal Department 45 - Water Management), in August 2018 a single specimen was found in the 22nd district and released in the Mühlwasser. The Mühlwasser is a former branch of the Danube at Stadlau (Vienna, 22. District); since 1875, there is no connection to the river anymore. Although the establishment status of the marble crayfish is unknown, there are two reasons for its inclusion in the list of Austrian aquatic neozoa. 1) the management of the Salzburg state fishing association (Salzburger Landesfischereiverband) must assume that the population cannot be eradicated (personal communication Mrs. Daniela Latzer, Salzburg); 2) an establishment (in the sense of permanent, reproducing populations) is to be assumed since the species reproduces parthenogenetically.

Keywords: None provided.

Latzer and Pekny, 2018

Salzburgs Fischerei 49(3) cover featuring Marmorkrebs
Latzer D, Pekny R. 2018. Erstnachweis des Marmorkrebses für Österreich in Salzburg. Salzburgs Fischerei 49(3): 24-30. https://issuu.com/lfvs/docs/safisch_3-18

Abstract

Der landesfremde Marmorkrebs wurde nun erstmals in Österreich, und zwar in Salzburg gefunden: dieser Krebs ist auch als sog. „Klon-Krebs" bekannt. Es kommen nur weibliche Tiere vor, die sich parthenogenetisch, also per Jungfernzeugung, fortpflanzen.

Keywords: None provided.

Approximate English translation of abstract:

The foreign marbled crayfish was now in Austria for the first time, specifically found in Salzburg: this crayfish is also known as the “clone crayfish.” Only females come from these animals, which reproduce parthenogenetically, i.e. by means of virgin generation.

Szendőfi and colleagues, 2018

Pisces Hungarici XII cover
Szendőfi B, Bérces S, Csányi B, Gábris V, Gál B, Gönye Z, Répás E, Seprős R, B. T, Kouba A, Patoka J, Weiperth A. 2018. Egzotikus halfajok és decapodák a Barát‐ és Dera‐patakban, valamint a torkolatuk dunai élőhelyein. Pisces Hungarici 12: 47-51. http://www.haltanitarsasag.hu/ph12/Szendofi_et.al_Pisces.Hungarici_2018.pdf

(English title: Occurrence of exotic fish and crayfish species in Barát and Dera
creeks and their adjacent section of the River Danube)

Abstract

Thermal and urban waters are frequently subjected to the releases of aquatic pets, which often occur in unexpected assemblages of native and non‐native species. To document this, we conducted a half‐year‐long (January – July 2018) field survey the crayfish and fish species present in Barát and Dera creeks (two sampling sites per each) and sections adjacent to their mouth in the River Danube. Sampling sites were inspected monthly using a combination of catching methods. Altogether, four non‐native crayfish, ten nonnative and twelve native fish were recoded. Several individuals of spiny‐cheek crayfish (Faxonius limosus), marbled crayfish (Procambarus virginalis), red swamp crayfish (Procambarus clarkii) and Australian redclaw (Cherax quadricarinatus) were sampled in the thermal water tributary of Barát creek. The Dera creek was not influenced with the thermal or industrial warm water, but the urbanised area affected the water quality, which was still acceptable for occurrence of spiny‐cheek crayfish, marbled crayfish and red swamp crayfish. Besides already well established population of spiny‐cheek crayfish, also marbled crayfish and red swamp crayfish inhabited the River Danube itself. Seven non‐native decapods have been reported in the Hungarian wild so far. However, this is to our knowledge the first published report on co‐occurrence of three North‐American crayfish as well as a combination of North‐American and Australasian crayfish species in Europe. The new faunistic records of exotic live‐bearing fish species from the family Poeciliidae and their hybrids from Barát creek were also obtained. These findings highlight the significance of pet trade as an introduction pathway and thermal as well as urban waters as target sites for new introductions. Roles of established nonnative species and their possible spread are issues requiring further targeted research.

Keywords: biological invasion • thermal water • tributary • Danube

Open access


26 June 2020

Link roundup for June 2020

Friend of the blogGünter Vogt has a write-up for non-specialists about Marmorkrebs at the Atlas of Science.

• • • • •

Great Lakes Now has a story about the efforts to keep invasive species out of the Great Lakes. It starts with Marmorkrebs being banned in Michigan, saying that the new policy made headlines. Other crayfish are discussed more in the article, mostly Louisiana red swamp crayfish.