Wednesday, March 17, 2010

Estill Fork Trip, March 15

I went out with Taito, Joe and Brittany from my lab yesterday to Estill Fork to make our monthly new moon driftnet collection of inverts and also to catch some fish. Taito who took the pictures didn't get any of the driftnet set-up so we'll move on to the fish collecting... We're interested primarily in telescope shiners (Notropis telescopus) from this system for a study of how fish brains may change between non-breeding and breeding seasons, especially differences between males and females, and sexually dimorphic species (like scarlet shiners) and sexually monomorphic species (like telescopes). March is an in-between month for breeding or non-breeding for these species.

Yesterday the site had high water, but not quite dangerously high, with an air temperature of about 48 deg. F and water temperature of about 45 deg. F. We caught most of the fish shown in the following pictures where the riffle system flows into the deep pool. In the summer we wade through it with a seine, but nose-deep water is too much this time of year.

Here's the view of the low roadway across the stream, historically a ford. Usually water doesn't overtop it. Over and beyond the ridge in the background is the Walls of Jericho tract, a de facto wildnerness owned by the state.

Here's myself, Joe and Brittany examining a net haul from just downstream of this small island. This was Joe's first fish-collecting trip.

This was one of our better hauls. The silvery shiners are mostly telescopes, with one tennessee shiner right in the middle. The larger, less silvery shiners are striped shiners, and there's also a number of fantail darters in this haul including very gravid females.

And finally, a photo of shiners caught in the act of flopping around on a hand. The top silvery one is a telescope, with a striped and scarlet going clockwise.

The next new moon is Wednesday, April 14, hopefully we'll be there.

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