Tuesday, August 01, 2006

I've Overcome More Species ID Doubts

The last two days I've been going back and forth about whether some flame chubs we've collected lately are truly flame chubs, or merely young of the related creek chub (Semotilus atromaculatus). I even woke up first thing this morning worrying about that... now that's bad! But I've resolved my doubts. The confusion stems from the fact that the flame chubs we've collected from two creeks, North Fork of Cypress Creek and Greenbrier Branch, are subadults. They don't show that vivid warm orange on the belly that breeding condition adults do, certainly not at this point in the season. But they do have the red patch at the front of the dorsal fin that is typical of flame chubs, without a black ocellus in it that's typical of creek chubs. The dark lateral line fades out in the caudal peduncle, leaving a dark spot at the base of the caudal. And the general body shape is right, more rotund and compressed looking than creek chubs. So I'm sticking with my official tally of finding flame chubs at 18 of the 47 historic collection sites in north Alabama that I've visited over the last 15 months.

My challenge is to draw up a coherent list of these 47 sites so that Kevin can update the amazing map he's designed for this project. I just now taped up a version that's almost 6 feet long and 3 feet deep, showing the top tier, two counties deep from Tennessee, of north Alabama along the Tennessee River. Most of the historic collection sites are indicated by circles with numbers corresponding to the sequence of sites listed in the University of Alabama Ichthyology Collection records that I'm working from. When I complete my list we can indicate sites that have flame chubs, that don't have flame chubs, or that I haven't been able to visit (yet). The information represented on the map now is that the strong majority of flame chub collections have been made in the Cypress Creek system north and northwest of the city of Florence in Lauderdale County, the northwest corner of the state. With a coherent statement of my data I hope to be able to give a coherent account of the condition of this species in the state. And, of course, you'll read it here first.

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