25 May 2010

Crays on the radio

Susan Lawler has a great essay on Australian crayfish on the radio show Ockham’s Razor this week. You can read a transcript here, but do yourself a favour and listen to the audio, if for no other reason than to hear her imitate the past president of the International Association of Astacology.

15 May 2010

Pic of the Moment: 15 May 2010

The dendritic tree of a motor neuron in Marmorkrebs, revealed by cobalt backfilling.

You might learn more about these if you’re attending the International Association of Astacology meeting in Missouri in July.

06 May 2010

Scientist at work

I’ve written quite a bit about the difficulties of conducting science in Madagascar, due to the political turmoil there. The New York Times has a new blog, Scientist at Work, that compiles field notes from working scientists, and first up is herpetologist Chris Raxworthy, who is doing field work in Madagascar. Unlikely he will mention Marmorkrebs, since he’s looking for chameleons, but worth checking out nevertheless.

04 May 2010

Farca Luna and colleagues, 2010

Farca Luna AJ, Heinrich R, Reischig T. 2010. The circadian biology of the marbled crayfish. Frontiers in Bioscience E2(4): 1414-1431. http://www.bioscience.org/2010/v2e/af/202/list.htm, http://dx.doi.org/10.2741/e202

The parthenogenetic marbled crayfish (Procambarus spec.) has recently been introduced as a new preparation for neuroethological studies. Since isogeneity apparently limits inter-individual variation, this otherwise typical decapod species may be especially valuable for circadian studies. Locomotor activity of isolated marbled crayfish and agonistic activity of small social groups maintain circadian rhythmicity in constant darkness. As potential signals of circadian time information, levels of 5HT, N-acetylserotonin and melatonin were determined in brains of marbled crayfish at different daytimes. However, location and structural organization of crustacean circadian pacemakers are still elusive. Immunocytochemical and backfill studies in the marbled crayfish revealed neural structures that may correspond to portions of circadian pacemaker systems in the insect optic lobe. Position and additional chemical contents in two pigment-dispersing hormone-expressing neuron groups resembled insect pigment-dispersing factor-expressing cells in the lamina and the accessory medulla, a neuropil discussed as center for integration of timing information. Here, we discuss new findings about the possible organization of the circadian system of the marbled crayfish in the light of current knowledge about circadian clocks in crustacea.

Keywords: None provided.