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Population ecology and prey consumption by fathead minnows in prairie wetlands: importance of detritus and larval fish
Author(s) -
Herwig B. R.,
Zimmer K. D.
Publication year - 2007
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2006.00220.x
Subject(s) - minnow , detritus , pimephales promelas , biology , ecology , predation , juvenile fish , abundance (ecology) , population , biomass (ecology) , juvenile , fishery , fish <actinopterygii> , demography , sociology
– The fathead minnow Pimephales promelas occurs in high densities in wetlands of the prairie pothole region (PPR) of North America, but food resources sustaining these populations are poorly known. We assessed population dynamics and prey consumption of fathead minnow populations in three PPR wetlands for 2 years. Fish density peaked at 107 fish per m 2 for all age classes combined. Larval and juvenile fish dominated these populations in terms of abundance and accounted for 83% of total prey consumption. Detritus dominated fish diets, representing 53%, 40% and 79% of diet mass for larval, juvenile and adult fish respectively. Detritus consumption was positively related to minnow density and negatively related to invertebrate abundance, but only for adult fish. Seasonal production:biomass ratios were unrelated to proportions of detritus in the diet for all ages of fish, indicating that detritus is an important food resource capable of meeting metabolic demands and sustaining fish growth in high‐density populations. Detritus consumption may also weaken links between abundance of invertebrate prey and minnows, promoting dense fish populations with strong, consistent influences on wetland ecosystems.