The Canadian River: A tale of two fishes Arkansas river shiner, Notropis girardi, and Peppered chub, Macrhybopsis tetranema

Authors: Tiffany Love-Chezem, Eliza Gilbert

Year: 2013 (xlv)

Abstract

In New Mexico, a remnant native population of Arkansas river shiner, Notropis girardi, occupies 20 river miles of the Canadian River, below Ute Dam. This federally endangered fish is estimated to be present in only 20% of its historic range. This section of the Canadian River is the only locality in the state of New Mexico where the state endangered Peppered chub, Machrybopsis tetranema, is present. Machrybopsis tetranema occupies 10% of its entire historic range. These two species have similar life histories though less is known about M. tetranema. New Mexico Department of Game and Fish set up 6 permanent monitoring sites within this 20 river mile section in 2012. Four samples are made each year and are used to establish seasonal and population trends. A sample location at Revuelto Creek, an ephemeral tributary, is also sampled when water is present. The importance of this tributary is unknown. It is used by N. girardi when water is present and since the flow of the Canadian River is limited by what seeps out of Ute Dam, flooding from Revuelto Creek may be what cues N. girardi spawning. Initial data for N. girardi indicates recruitment of Age 0-1 fish in late summer samples (August/September). This is consistent with known life history, reproduction occurring during high flows in June and July. The fall sample shows a reduction in CPUE in all age classes of N. girardi continuing to decrease in the winter sample. In the spring, the abundance of fish climbs which may indicate that fish are migrating from downstream reaches in Texas. This is supported by the collection of two fish with VIE markings that were released in the Canadian River near Amarillo, TX. Historical data for M. tetranema dates back 1939. Until 2006, M. tetranema was caught consistently, with some years resulting in the capture of hundreds of individuals per site. During the past two years of sampling, only 4 individuals have been caught. This reduction in M. tetranema population seems to be consistent throughout their range and the cause is not well understood especially considering that N. girardi has been relatively stable. Initial data from this study and historical data have provided us with specific questions for these two rare species that can be explored further with data obtained from this sampling effort.