Effects of Fish Communities on Presence and Abundance of Kisatchie Painted Crayfish in East Texas

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biological and Environmental Sciences

Date of Award

Spring 5-1-2026

Abstract

The Kisatchie Painted Crayfish, Faxonius maletae, is an elusive, rare, imperiled (G2) crayfish species endemic to the Cypress River basin of East Texas and watersheds of central Louisiana. F. maletae is currently considered data deficient regarding the biotic and abiotic factors that affect their occurrence and abundance. From May to December 2025, we sampled the fish and crayfish assemblages of 30 stream sites in the Cypress River basin by electrofishing and seining across two sampling events: the first for crayfish by targeting preferred microhabitats and the second for fish. We collected 211 F. maletae individuals at 14 sites and 44 fish species, 17 of which were considered potential crayfish predators and 10 of which were considered potential competitors. First, we performed a negative binomial regression and determined that bullhead (Ameiurus melas and Ameiurus natalis) abundance was the most significant biotic predictor of F. maletae abundance (coefficient = -0.675, p = 0.040). We also used NMDS and PermANOVA to analyze the effects of fish assemblage composition on the presence and abundance of F. maletae. We found that while fish assemblage compositions were not significantly different between sites with and without F. maletae (F = 1.46, R2 = 0.050, p = 0.114), they did significantly differ at sites of high and low F. maletae density (F = 2.64, R2 = 0.086, p = 0.002). This suggests fish do not exclude F. maletae but act as population suppressors. By running an indicator species analysis, we found that abundance of three sunfish species was associated with low F. maletae densities. Conversely, increased abundances of five small fish species are associated with high F. maletae densities. Our results indicate predatory fish are capable of suppressing population growth for F. maletae within the Cypress River basin. This information will be helpful in the development of a conservation management plan for this imperiled species.

Advisor

Bjorn Schmidt

Subject Categories

Biology | Life Sciences

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