Selective particle ingestion by a filter‐feeding fish and its impact on phytoplankton community structure1

Abstract

The ingestion rates of filter-feeding gizzard shad for different sizes of suspended particles were measured using mixtures of microspheres and zooplankton. Ingestion rate increases as a function of particle size, leveling off at 60 pm. The particle-size-dependent ingestion rates were consistent with a model of filtering efficiency based on the cumulative frequency of interraker distances of gizzard shad gill rakers.Comparison of ponds containing gizzard shad with control ponds without fish showed that gizzard shad suppressed Ceratium, the only phytoplankton species large enough to be ingested at a maximum rate. Gizzard shad did not have a significant effect on populations of Synedra, Peridinium, Navicula, Kirchneriella, Cyclotella, and Chlamydomonas. Populations of Ankistrodesmus, Cryptomonas, Cosmarium, Rhodomonas, and algae and bacteria from 2-4 pm were enhanced by gizzard shad.

Linking Landscapes and Food Webs: Effects of Omnivorous Fish and Watersheds on Reservoir Ecosystems

“…The feeding mode of gizzard shad also changes at this time. Whereas larvae visually feed on individual prey items, juveniles and adults are pump-filter feeders; in this latter mode they can essentially vacuum-filter organic matter from sediments (Drenner et al 1984). Thus, as YOY gizzard shad become juveniles, their diets can broaden from zooplankton to detritus as well, with the actual diets of postlarval gizzard shad depending somewhat on the relative abundance of potential foods.…”

Impacts of Filter-Feeding Fishes on the Long-Term Changes of Crustacean Zooplankton in a Eutrophic Subtropical Chinese Lake

“…Thus fish predation may have been the factor determining the relative abundance of these two species. D. brachyunrm was reported as capable of escaping predation by Rlter feeders Drenner et al 1982Drenner et al . 1984aDrenner et al .…”

“…Field evidence shows that predation pressure by pump filter-feeding fish tends to shift the zooplankton community toward the more evasive zooplankters. such as calanoid copepods (Drenner et al 1982(Drenner et al , 1984a(Drenner et al . 1984b and that silver carp (Hypopthufmichulys molitrkj and bighead carp (Aristichthys nobills) favor nanophytoplankton over netphytoplankton W j a k 1975.…”

SRS ecology: Environmental information document

“…During 1986 and, when densities of the planktivorous threadfin shad were low, these larger, more easily seen and thus more vulnerable species existed in the lake. However as threadfin shad, voracious consumers of large zooplankton (Drenner and McComas 1980;Drenner et al 1984;Prophet and Frey 1987) increased, they began to drive their preferred prey to extinction in the lake. By 1990, copepod and cladoceran were nonexistent in the open waters of L Lake.…”