Undergraduate Abstract

Nathan Lenon
December 2000

Predator-Prey Interactions Between Bonytail Chub (Gila elegans) and Red Swamp Crayfish (Procambarus clarkii)

A Thesis submitted in partial satisfaction
of the requirement for the degree of

Bachelor of Science

In

Environmental Studies Program
University of Nevada Las Vegas

by

Nathan Lenon

Fall 2000

Thesis Advisors:

Tom Burke
Regional Fishery Biologist, U.S. Bureau of Reclamation

Dr. James Deacon
Distinguished Professor
Environmental Studies Program
University of Nevada Las Vegas

Dr. Krystyna Stave
Assistant Professor
Environmental Studies Program
University of Nevada Las Vegas

ABSTRACT

This study examined the potential use of Bonytail Chub (Gila elegans) as a method of biological control of Red Swamp Crayfish (Procambarus clarkii), to supplement ongoing trapping efforts. Controlled laboratory experiments were conducted to quantify the size range of crayfish that are too small to trap using ¼ inch mesh. Feeding trials were performed, using young-of-year crayfish 3mm to 21mm carapace length (CPL), to access the effect of predation by Bonytails. Bonytail Chubs consumed crayfish ranging from 3mm to 17mm CPL. Bonytails consumed crayfish in the presence of fish pellets, as well as when cover was provided for the crayfish. Bonytails consumed crayfish with a total length (TL) up to 25% of their own total length. Larger fish consumed only slightly larger crayfish than did smaller fish, suggesting that the size of prey consumed does not increase substancially, as the fish grow in length. The results of this study suggest that stocking juvenile Bonytail Chubs into ponds with high crayfish populations could decrease the abundance of early life stages of crayfish.