Monday, September 26, 2011

Our Last Transecting Trip To Estill Fork

Five of us went out to Estill Fork in the upper Paint Rock River valley on Saturday. This trip completes the field work aspect of both Robert's and Brian's thesis projects. We have a full year's worth of several darter species for Robert's examination for gill parasites, and we've completed 7, I think, visits to Estill Fork for Brian's transect examination of physical habitat and darter usage. It was a beautiful early fall day, warm and sunny, and I'm not sure we really broke a sweat doing this work. The first photo below is my standard view of the low bridge across the stream looking east, from the perspective of where we park.

The stream had low but flowing water. Much of the streambed was covered with water willow, usually with several inches of water flowing around the base of the plants.

Many of the autumn blooming plants were in flower. Below is a cardinal flower plant. They prefer really wet soil right on the edge of a stream, and there were a lot of them at this site in such soils.

I know I know what the next plant is, but the name escapes me. (Edit: They're blue Lobelia, a relative of the cardinal flower.) They're found along the stream in drier, more elevated soils than the cardinal flower.

All sorts of asters were in bloom, of course, this being late September. I'm sure someone could tell me exactly what species is in the next photo.

This view of our vehicles makes it look like we're parking in a meadow, but we're actually off the roadway between two large meadows. It looks very autumnal, of course.

And finally, here's a high-contrast view of the stream itself, shadows mixing with spots of bright sunlight breaking through the canopy. The water was extremely clear.

Wednesday, September 21, 2011

Manuscript Fully Accepted At Southeastern Naturalist

It's been too long since I last posted. My immediate spur is hearing from Anne, the editor at Southeastern Naturalist, that the article by Andrew, Brittany and me on gill parasite infection in telescope shiners has been fully accepted, and should come out in print in 3-6 months. I have to thank Don Cloutman for working with me as the guest editor for this paper, improving it hugely. Following is the final Abstract for the article:

Dactylogyrus is a holarctic genus of monogene flatworms that infects the gills of cyprinid fishes. Dactylogyrus species are usually highly host specific, and little is known about their life history in North America. The purpose of this study was twofold: to determine whether Dactylogyrus exhibits seasonality in its life cycle, and if there is any effect upon reproductive effort of the host as a result of Dactylogyrus infection. Over a 12-month period, 967 Dactylogyrus were found on the gills of 383 Notropis telescopus (Telescope Shiner), a cyprinid fish collected in the upper Paint Rock River system in northeastern Alabama. A significant positive relationship was found between host somatic weight and prevalence of infection, and a significant positive correlation between higher intensity of infection and gonadosomatic index (GSI). The assumptions that parasites are evenly distributed among individual host fish and in each month were rejected by chi square tests, with the months of March through July as a peak for the extent of Dactylogyrus infection. These months are the time of gonadal development and reproduction in Telescope Shiners.

Sunday, September 11, 2011

Photos From Estill Fork On August 26

I went to Estill Fork last Aug. 26 with Robert, Alex and Jeremy to collect darters for Robert's gill parasite project. We were able to collect a good number of stripetails, and enough rainbows and redlines to make it worthwhile. The water was way down since it hadn't rained for three weeks, as seen in the photo below -

Robert and Alex are hanging out on the bank as we prepare to pack up the darters in very dilute formaldehyde to take home on ice.

Robert makes sure the euthanized darters are in enough of 1/4000 formaldehyde before putting them on ice.

We'll have to return later this month, for the last darters for Robert's project, and to do the last transect for Brian's project. The stream should be somewhat higher with the almost 15 cm of rain we've received so far this month.

Saturday, September 03, 2011

A Manuscript For My Friends At Freshwater Biology

Yesterday I submitted the manuscript based on Brittany's thesis work to Freshwater Biology. It has the very direct title of, "Invertebrate Drift in Estill Fork, Jackson County, Alabama" with Brittany and me as co-authors in that order. FB has published other studies of stream drift, so hopefully they'll like ours, too.

We've organized the silver shiners (28) and blotched chubs (32?) from last Sunday, starting with basic length/gross weight measurements and giving each individual a name and an attached paper tag with that name. Some of the chubs are obviously this year's young-of-year, and I think three of what we've ID'd as silver shiners are juveniles, too. I hope that we can establish year classes by length bins, examine patterns of gonadal maturation come late winter and spring, and observe gill parasite infection patterns and rates. From what I can tell the silver shiners are especially poorly studied, so I think such a project can make contributions to our knowledge of these species and their ecosystems.