Significance of Detritus or Detritus-Associated Invertebrates to Fish Production in a New Impoundment

Abstract

During early stages of succession in a new impoundment, fish species that could assimilate the readily available food resources, i.e. carp (Cyprinus carpio) and flat bullhead (Ictalurus platycephalus) were initially favored in numbers and weight. Detrital feeders or omnivores represented by carp and the flat bullhead comprised a majority of the numbers (56%) and weight (65%) of the 25 species captured during a 2-yr period. Numbers of the major fish groups captured decreased from 1971 to 1972, while the weight per species increased.On a volumetric basis, detritus and detritus-associated invertebrates (coleopterans and dipterans), were the major food items consumed by carp and catfish. Relative abundance of animal food items, in terms of frequency of occurrence and percentage of stomach contents, was greater at warmer water temperatures. In comparison to other species, catfish contained the greatest diversity of food items during warmer months and consumed larger quantities of detritus in the winter. Fish groups that constituted a smaller biomass, such as centrarchids, were generally insectivorous or fed upon cladocerans and copepods, while adult basses (Micropterus salmoides and M. coosae) and chain pickerel (Esox niger) were piscivorous.