Competition through predation ability of juvenile apex predator species-sacramento pikeminnow (Ptychocheilus grandis) and largemouth bass (Micropterus salmoides)

Conservation of native fishes in California waterways is of high concern due to increasing numbers of native species gaining threatened or endangered status. Research geared towards the conservation of native species takes on both an environmental and biological approach. Environmental research focuses on the conservation of species via environmental change, yet fails to consider biological interactions of species within the environment. Biological approaches include the interactions of intraspecific and interspecific competition. Interactions of intraspecific and interspecific competition have historically been researched in a variety of species. Although previous research of intraspecific and interspecific competition proves necessary in understanding relationships in an ecosystem, such research can be limited by observing species in the adult stage. Juvenile predation studies are important to consider when implementing plans, policies, and practices for conservation. These studies allow insight into how a species at the juvenile stage can acquire fitness in the environment by way of predation. Highly effective predation ability of one species can influence the existence of a less effective predator as both mature into breeding adults. Sacramento Pikeminnow (Ptychocheilus grandis) is a species of fish native to California and competes for habitat with Largemouth Bass (Micropterus salmoides). Largemouth Bass is a species of popular warm water sports fish, introduced to California in the late 1800s. The species is listed as a keystone species and is responsible for biotic and abiotic changes to the ecosystem. The objective of this study was to determine if apex predator establishment can be ascribed to species-specific predation ability of fishes at the juvenile stage. To accomplish this objective, data on exploitation competition by way of intraspecific and interspecific predation ability of the two juvenile apex predators were recorded over a course of five weeks by using growth and handling time of prey as indicators of predation ability. For the purpose of the research, juvenile fishes were defined as those measuring 50-100 mm total length. Samples of fishes were collected along stretches of lower Putah Creek in Yolo County, California during the cool months of early spring 2016. Data on predatory capability at the juvenile stage were statistically analyzed using both a three-way and two-way Analysis of Variance (ANOVA) to determine if predator success can be ascribed to species-specific predation ability. Results of the three-way ANOVA used to analyze growth via changes in standard length (mm), total length (mm) and mass (g) of fishes proved statistically insignificant. Results of the two-way ANOVA used to analyze handling time of prey illustrated statistical significance. Statistical significance of handling time indicates that predator success can, in part, be ascribed to species-specific predation ability.