Premium
The Effects of Macrophyte Stem Density and Structural Complexity on Foraging Return of Invertivorous Juvenile Largemouth Bass
Author(s) -
Stahr Kristopher J.,
Shoup Daniel E.
Publication year - 2016
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1080/02755947.2016.1173142
Subject(s) - micropterus , bass (fish) , foraging , macrophyte , biology , juvenile , predation , centrarchidae , ecology , fishery
Aquatic vegetation can impact juvenile fishes through multiple pathways. Previous studies have found that dense macrophytes can cause a trade‐off of survival for Bluegills Lepomis macrochirus , with decreased foraging efficiency in macrophytes but also decreased predation risk. For juvenile Largemouth Bass Micropterus salmoides , this phenomenon has been proposed but never experimentally tested. In addition, little information exists on the effects of vegetation on juvenile Largemouth Bass prior to the shift to piscivory, a critical period in the recruitment process. Therefore, the objective of this study was to determine if aquatic vegetation reduces the foraging ability of invertivorous (prepiscivorous) juvenile Largemouth Bass. Twenty‐four invertivorous juvenile Largemouth Bass were tested individually at each of five stem densities (0, 125, 250, 500, and 1,000 stems/m 2 ) of artificial macrophytes within 20.8‐liter aquaria. Five treatments of a simple stem architecture (at all stem densities) and three complex stem architecture treatments (125, 250, and 500 stems/m 2 ) were used within this experiment. Complex stem density treatments were created using a branched design which doubled the string abundance (number of strings) within the water relative to corresponding stem densities in simple vegetation treatments. Thirty chironomid larvae were used as prey during each 15‐minute foraging bout. Foraging return (number of chironomid larvae consumed/15‐minute foraging bout) was not significantly different among all stem treatments. Therefore, our results suggest the predator avoidance advantage aquatic macrophytes provide to juvenile Largemouth Bass does not come with a trade‐off in foraging efficiency (up to 1,000 stems/m 2 vegetation density), at least when Largemouth Bass are prepiscivorous. Received December 15, 2015; accepted March 23, 2016 Published online July 7, 2016