Document Type

Article

Publication Date

2012

Departmental Paper Identifier

NRM-80

Keywords

bluegill, competition, Daphnia, priority effects, yellow perch

Abstract

1. When available, Daphnia spp. are often preferred by age-0 yellow perch and bluegill sunfish because of energetic profitability. We hypothesised that predation by age-0 yellow perch could lead to a midsummer decline (MSD) of Daphnia spp. and that priority effects may favour yellow perch because they hatch before bluegill, allowing them to capitalise on Daphnia spp. prior to bluegill emergence. 2. Data were collected from 2004 to 2010 in Pelican Lake, Nebraska, U.S.A. The lake experienced a prolonged MSD in all but 1 year (2005), generally occurring within the first 2 weeks of June except in 2008 and 2010 when it occurred at the end of June. MSD timing is not solely related to seasonal patterns of age-0 yellow perch consumption. Nevertheless, when Daphnia spp. biomass was low during 2004 and 2006–2010 (<4 mg wet weight L)1 ), predation by age-0 yellow perch seems to have suppressed Daphnia spp. biomass (i.e. <1.0 mg wet weight L)1 ). The exception was 2005 when age-0 yellow perch were absent. 3. Growth of age-0 bluegill was significantly faster in 2005, when Daphnia spp. were available in greater densities (>4 mg wet weight L)1 ) compared with the other years (<0.2 mg wet weight L)1 ). 4. We conclude that age-0 yellow perch are capable of reducing Daphnia biomass prior to the arrival of age-0 bluegill, ultimately slowing bluegill growth. Thus, priority effects favour age-0 yellow perch when competing with age-0 bluegill for Daphnia. However, these effects may be minimised if there is a shorter time between hatching of the two species, higher Daphnia spp. densities or lower age-0 yellow perch densities.

Publication Title

Freshwater Biology

Volume

57

First Page

654

Last Page

665

Pages

12

Format

application/pdf

Language

en

DOI of Published Version

10.1111/j.1365-2427.2011.02728.x

Publisher

Blackwell

Rights

A work produced within the official duties of an employee of the United States Government are not subject to copyright within the U.S.

Comments

This work is from Freshwater Biology (2012) 57, 654–665.

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