The primary focus of this research project was on fish ecology and physiology. While most some animals can be flexible in terms of their body stoichiometry, the mechanism by which dietary nutrient content affects fish body stoichiometry and growth is still poorly understood, particularly for piscivores (fish who eat other fish). To better understand these relationships, we performed a controlled experiment on 30 young-of-year largemouth bass (Micropterus salmoides), in which bass were fed three different prey types differing in body phosphorus (P) content. Prey items varied in P including annelid worms (low-P), adult fathead minnows (medium-P), and larval bluegill (high-P). Bass were fed these three diets for about one month, after which their growth rate and body stoichiometry were measured. Bass growth rate differed significantly among treatments (p < 0.001). The growth rate was highest under the minnow diet (0.03 g/day), lowest with larval bluegill (0.003 g/day), and intermediate with the bloodworm diet (0.01 g/day). Thus, growth did not necessarily correlate directly with dietary phosphorus growth since minnows produced the highest growth rate. P growth efficiency was also highest in the annelids suggesting that p-content in fish may be less digestible. While growth of juvenile piscivores may be P-limited due to their need to build bones and scales during early development, our results indicate that growth is a function of both P content and P digestibility of prey. Therefore, digestibility may be a key factor to consider when investigating the natural diets of piscivores in fisheries. This research allowed me to grasp a much more comprehensive understanding of fish physiology and feeding habits which will help me pursue a career in fisheries management.
Author: Michael Easley
Advisor: Michael Vanni, Biology
Graduate Advisor: Kaitlyn Busch
You must be logged in to post a comment.