Marmorkrebs continue their rise in Germany

Peay S. 2009. Invasive non-indigenous crayfish species in Europe: Recommendations on managing them. Knowledge and Management of Aquatic Ecosystems 394-395: 3. http://dx.doi.org/10.1051/kmae/2010009

This paper contains a couple of mentions about Marmorkrebs (though they are so brief that doesn’t quite rate a separate entry in the abstracts). The most important one is this:

At least three new populations of marbled crayfish Procambarus sp. have been found in the wild in Germany in the past two years, all aquarium discards (Chucholl, pers. comm.).

“Chucholl” is Chris Chucholl, who is studying ecology and invasive species issues.

Holdich and colleagues, 2010

Holdich DM, Reynolds JD, Souty-Grosset C, Sibley PJ. 2010. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species. Knowledge and Management of Aquatic Ecosystems 394-395: 11. http://dx.doi.org/10.1051/kmae/2009025

Non-indigenous crayfish species (NICS) in Europe now outnumber indigenous crayfish species (ICS) 2:1, and it has been predicted that they may dominate completely in the next few decades unless something is done to protect them. Of the ten NICS introduced at least nine have become established in areas occupied by four of the five ICS. A decline in stocks of ICS has been recorded in many countries in the face of increasing populations of NICS. Most European countries retain at least one ICS but all are under threat from habitat loss, deteriorating water quality, overfishing, climate change, and most importantly from NICS and crayfish plague. The threat to ICS is so great in some countries that “ark” sanctuary sites are being established.

The three most widely-spread NICS are the North American species: Pacifastacus leniusculus, Orconectes limosus and Procambarus clarkii. These can be considered as “Old NICS”, which were introduced before 1975, compared with the “New NICS”, which were introduced after 1980, such as the North American species: Orconectes immunis, Orconectes juvenilis, Orconectes virilis, Procambarus sp. and Procambarus acutus; and the Australian species: Cherax destructor and Cherax quadricarinatus, all of which have much narrower ranges in Europe. The North American species are potentially capable of acting as vectors of crayfish plague. Outbreaks of this disease occur regularly where there are high concentrations of vectors.

In addition to the NICS currently established in the wild, a further threat exists through the aquarium trade, where many American and Australian species are available via the internet and in aquarist centres. Owners of such species may discard them into the freshwater environment when they grow too big as with some Cherax spp. and Orconectes spp., or multiply too frequently as with Procambarus sp. (a parthenogenetic species). A conceptual model is presented as a possible way forward for protecting the future survival of ICS in Europe.

Keywords: None provided.

On their way

My cup runneth over. I’ve just updated the home page and the list of research papers with references to three five exciting new Marmorkrebs papers that are now in press.

A preprint of one is available now. The abstracts will join the compilation here on the blog when the final, paginated versions are published.

Additional: Two more papers added on 8 July 2010.

The problem with a coup détat

Madagascar is now home to one of the world's "unsupervised" Marmorkrebs populations. But, as I've noted before, the place is a political mess. The political mess has spilled over into a conservation mess.

That's the problem with a coup détat: Everyone assumes they can literally take anything they want.

That quote is from primatologist Patricia Wright. In this detailed interview, she lays out the current state of the situation in all its complexity.

Celebrate diversity: Lesbian lizard sex

I have a hard time remembering the name Aspidoscelis uniparens, because when it first broke into the limelight, it was Cnemidophorus uniparens. Sort of like how everyone continued calling Prince “Prince” even after he changed his name to a squiggle. If only he’d been known as a squiggle first when he released “Little Red Corvette”...

Regardless of the genus name, I love this lizard. This was probably the first parthenogenetic animal that made an impression on me, when I was an undergraduate.

That there were no males in this species – a vertebrate! – was interesting enough. But what made this doubly wild was that while there was absolutely no genetic need for any other individual, these lizards, if given the opportunity, would perform pseudocopulation. That is, if you saw two lizards, they would engage in behaviour that, if you didn’t know they were both female, you would say, “They’re getting some action.” Yeah, you know what I’m talking about.

Now that is the sort of thing that impresses upon an undergraduate how little she or he knows about the natural world.

It makes sense, as so many things do, when viewed from an evolutionary point of view. If these animals evolved from a sexual species, the behaviour may lag behind the genetic changes. Sort of how like the hottest days of the year are usually a bit after the longest days of the year.

There’s a series of papers on this lizard, mainly from the lab of David Crews. He’s authored many other papers on many other species besides Aspidoscelis uniparens, I should say.

Reference

Crews D, Fitzgerald KT. 1980. "Sexual" behavior in parthenogenetic lizards (Cnemidophorus). Proceedings of the National Academy of Sciences of the United States of America 77(1): 499-502. http://www.pnas.org/content/77/1/499.short

Color photo by Manrus on Flickr. Used under a Creative Commons license.

Mystery book

I have no idea what this listing on the Amazon UK site is supposed to be. The listed publisher has a list of books that all seem to be lists of things, with May 2010 publication dates and the same non-cover cover. And weirdly, the “used” copies show up as costing more than the “new” copies. The ISBN number showed up in a search, but the publisher didn’t appear in a Google search.

It feels like there’s a scam of some sort going on here, but I can’t for the life of me figure out what it could be.

European Crayfish conference

The email I got announcing this conference opened in a way that seemed to me to reflect the nation where the meeting is being held...

To everybody passionate about crayfish!

“European Crayfish: Food, Flagships and Ecosystem Services” will held in Poitiers, France (26–29 October 2010). The conference website is now open. Seating is limited to 110 participants. The registration deadline is the end of June for regular membership. You can continue to register until 20 September, but costs go up after June.

A special issue of Knowledge Management of Aquatic Ecosystems (http://www.kmae-journal.org/) will be dedicated to this conference.

Discussion of the European Inland Fisheries Advisory Commission (EIFAC) crayfish working party will be held at this meeting.

For more information, contact Catherine Souty-Grosset at eucrayfish2010@ml.univ-poitiers.fr.