Pic of the Moment: 19 February 2008

A Marmorkrebs embryo stained with fluorescent nuclear dye, about half-way through development. From Seitz and colleagues (2005).

Ideas that spread and research publishing

The rationale for this website was directly inspired by this TED talk by Seth Godin. Early in the talk, Seth presents a simple mantra:

Ideas that spread, win.



I created Marmorkrebs.org to spread an idea: Marmorkrebs are an exciting and fascinating organism for research.

The jury is still out on whether I will win.

But as I've been compiling all the abstracts to research articles, I've noticed that all of them are protected by journal publishers in one way or another. Some are more liberal than others. The Journal of Experimental Biology, for instance, makes everything available to everyone for free after one year.

I support intellectual property rights. For that reason, I only post abstracts of research papers here. I have no intention of archiving research papers that publishers normally protect behind passwords and subscriptions. If those articles are freely and publicly available, that would be another matter; I would archive those. But currently, none are.

It's important to ask what the benefits of limiting information are. For instance, publishing in journals that have a strong reputation can help to establish the credibility of information. Plus, given that many researchers read more abstracts of papers than entire papers, it may not matter if the main text of a research paper is password protected online if the abstract summarizing the most important points can be read freely. There are many books that I know a lot about -- even though I have never read them! -- because I've read so many reviews of them.

It's also encouraging that some journals, which normally protect their research papers and charge fees to get them, are starting to offer authors a choice to allow their papers to be open access. For a fee, naturally.

Issues like this are why you can find a Creative Commons license on this page. I wanted to state specifically that people are free to spread the ideas contained in this blog, provided people follow the scholarly practice of attribution.

These issues of intellectual property are key to scientific communities, particularly young ones like this little Marmorkrebs community. I hope that next time someone has a Marmorkrebs paper to publish, they think about how well they are spreading their ideas.

Vogt and colleagues, 2008

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://dx.doi.org/10.1242/jeb.008755

Abstract

The phenotype of an organism is determined by the genes, the environment and stochastic developmental events. Although recognized as a basic biological principle influencing life history, susceptibility to diseases, and probably evolution, developmental variation (DV) has been only poorly investigated due to the lack of a suitable model organism. This obstacle could be overcome by using the recently detected, robust and highly fecund parthenogenetic marbled crayfish as an experimental animal. Batch-mates of this clonal crayfish, which were shown to be isogenic by analysis of nuclear microsatellite loci, exhibited surprisingly broad ranges of variation in coloration, growth, life-span, reproduction, behaviour and number of sense organs, even when reared under identical conditions. Maximal variation was observed for the marmorated coloration, the pattern of which was unique in each of the several hundred individuals examined. Variation among identically raised batch-mates was also found with respect to fluctuating asymmetry, a traditional indicator of the epigenetic part of the phenotype, and global DNA methylation, an overall molecular marker of an animal's epigenetic state. Developmental variation was produced in all life stages, probably by reaction–diffusion-like patterning mechanisms in early development and non-linear, self-reinforcing circuitries involving behaviour and metabolism in later stages. Our data indicate that, despite being raised in the same environment, individual genotypes can map to numerous phenotypes via DV, thus generating variability among clone-mates and individuality in a parthenogenetic species. Our results further show that DV, an apparently ubiquitous phenomenon in animals and plants, can introduce components of randomness into life histories, modifying individual fitness and population dynamics. Possible perspectives of DV for evolutionary biology are discussed.

Keywords: genotype • phenotype • variation • marbled crayfish • development • growth • colour • reproduction • behaviour • sense organs

Crayleks!

I can honestly say I never expected this.

Dawn of the Crayleks!

It's a story featuring Marmorkrebs from The Files of Hydrogen Guy!

Part I
Part II
Part III

Thanks to Günter Vogt for the tip!

Note to Americans and mundanes: "Crayleks" pay homage to the Daleks (pictured), evil aliens from the BBC television series Doctor Who.

Vogt, 2007

Vogt G. 2007. Exposure of the eggs to 17α-methyl testosterone reduced hatching success and growth and elicited teratogenic effects in postembryonic life stages of crayfish. Aquatic Toxicology 85(4): 291-296. http://dx.doi.org/10.1016/j.aquatox.2007.09.012

Abstract

Testosterone is regularly found in the tissues of decapod crustaceans. Although this vertebrate-type sex hormone is not the principal factor of sex differentiation in crustaceans, it was shown to be capable of acting on the reproductive organs of shrimps and crabs. In the present study I have exposed developing eggs and stage 5 juveniles of the parthenogenetic all female marbled crayfish to 17α-methyl testosterone in order to test whether in freshwater crayfish sex can be changed from female to male by this androgen. MT did not elicit sex change, neither when administered during embryonic development nor during juvenile stage 5, the main period of proliferation of the oocytes. However, exposure to 100 μg/L MT from 64% to 84% embryonic development resulted in prolonged embryonic development, reduced hatching success, reduced growth of the juveniles, and severe malformations of the appendages in the juveniles. The marbled crayfish is recommended to be considered for toxicity tests due to its easy culture in the laboratory and its genotypical uniformity.

Keywords: methyl testosterone • marbled crayfish • toxicity • teratogenicity • ovarian development • sex differentiation

Housing

What would an ideal Marmorkrebs rearing system look like?

Housing Marmorkrebs poses interesting problems, not the least of which is because Marmorkrebs reproduce so quickly. Using regular aquariums of the sort commonly found in pet stores certainly works, but can take up a lot of bench space. There may be a lot to be learned from zebrafish and Xenopus researchers, who are numerous enough that there are specific aquarium systems dedicated to housing large numbers of animals, collecting offspring, etc.

Aquatic Habitats offers some interesting systems (pictured). Our department has been using a benchtop system to house invertebrates for teaching purposes, and it is a decided improvement over lots of individual little tanks.

Another company worth looking into is Aquatic Eco-Systems, which has a variety of supplies. I'm particularly fond of their acrylic tanks, which I am currently using to house Marmorkrebs. The tanks are lightweight, making them much easier to move around. They are much less susceptible to cracking.

As the Marmorkrebs community grows, it will probably be important to work with these sorts of businesses to develop a standard set-up for someone who wants to establish a Marmorkrebs colony for research.

SICB 2008 review

To anyone who heard about this page at the recent SICB meeting in San Antonio -- welcome!

The SICB meeting was a far more eventful meeting for me personally than I expected. I hadn't fully realized the extent of the decapod crustacean contingent that would be there. It was really wonderful for me to meet a lot of people that I knew only by their published papers. Being a neuroethologist, I usually go to neurobiology and animal behaviour kinds of meetings, and hadn't really interacted with the crustie researchers at conferences very often before.

I had a chance to talk to a lot of people about Marmorkrebs, and gleaned some news, both good and bad. The good news was to learn of another paper about Marmokrebs coming out in The Journal of Experimental Biology in the next few months. The abstract will be posted here when it is published, as usual.

The bad news -- and it is very bad -- is that Marmorkrebs have now been found in Madagascar. Crayfish are harvested quite extensively there, as you can see in the video below, from the WWF.



While Marmokrebs are wonderful research animals, their potential as pests is just as great.