Saturday, June 26, 2010

Curating Darters

I realize that it's been a week since I posted. I've been distracted by helping to host visiting candidates for several of our open positions. My big advance of the week was curating darters from Estill Fork that we collected in May and June. This involves weighing, measuring and numbering each fish and placing it in its own 15 ml tube with 10% phosphate buffered formaldehyde. I hope to start examining gill arches for trematode parasites sometime in the near future. Tennessee Darters are our primary focus, and also I have a number of Rainbow Darters and Fantail Darters.

My new computer game hobby is grooming and aligning DNA sequences from Fundulus similis and F. majalis. Geneious is a surprisingly powerful program for this kind of work. To the cyt-b gene sequences I have from Dauphin Island, AL, and Key West, FL, I downloaded the only available sequences available on GenBank, three for each species, that don't exactly match mine. My sequences cover roughly nucleotide positions 350-1140 (the end of the gene), while the ones I downloaded are positions 1-990. So it's about 550 nucleotides that overlap, which makes them useful I hope. From preliminary tree building with this material the Key West sequences are markedly different from all others, with the Dauphin Island sequences distinct but not way out there. The suggestion has been made in the past that the Key West population of F. similis is deserving of subspecies designation because of some morphological distinctness. My data may support this to at least some degree (even if I think the concept of subspecies is squishy, as opposed to simply a distinct population within a species). We'll see how this plays out.

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