The food source of sediment-ingesting animals is a subject of controversy, centering on the notion that the microbial biomass in sediments is insufficient to support caloric need. Gizzard shad Dorosoma cepedianum are omnivorous, sediment-ingesting fish that frequently impact the trophic structure of temperate lake and reservoir food webs. Prior gut content analyses of this fish have typically d...

Gizzard shad (Dorosoma cepedianum) were collected from four locations in western Lake Erie during summer, 1982. The nutritional quality of foods ingested by these fish was examined. Small (<60 mm standard length), age 0 fish consumed mostly zooplankton with high organic (>80% of dry weight) and nitrogen (>6% of dry weight) contents. The phytoplankton and detritus diets of larger, age 0 and adul...

Agricultural activities increase exports of nutrients and sediments to lakes, with multiple potential impacts on recipient ecosystems. Nutrient inputs enhance phytoplankton and upper trophic levels, and sediment inputs can shade phytoplankton, interfere with feeding of consumers, and degrade benthic habitats. Allochthonous sediments are also a potential food source for detritivores, as is sedim...

To estimate the population of migrating shad fish in rivers, a method analysing acoustic signals during spawning is proposed. This method is based on a short-term spectral analysis, combined with a classification with a Gaussian mixture model, it results in detecting and counting shad spawning acts. The application has been implemented on a smartphone, which serves as an automatic counting devi...

Most stoichiometric models do not consider the importance of ontogenetic changes in body nutrient composition and excretion rates. We quantified ontogenetic variation in stoichiometry and diet in gizzard shad, Dorosoma cepedianum , an omnivorous fish with a pronounced ontogenetic diet shift; and zebrafish, Danio rerio, grown in the lab with a constant diet. In both species, body stoichiometry v...

—Competition with gizzard shad Dorosoma cepedianum has been shown to influence survival of larval bluegills Lepomis macrochirus as well as growth and size structure of largemouth bass Micropterus salmoides, which prey on these planktivorous species. However, little is known about how the presence of gizzard shad influences bluegills beyond the larval stage. We examined bluegill–gizzard shad int...

Understanding food-web ecology is valuable to conservation by linking interactions of multiple species together and illustrating the functionality of trophic exchange. Alosa alabamae (Alabama Shad), an anadromous species, reproduces in northern Gulf of Mexico drainages from February through May, and for this study, the Pascagoula and Apalachicola rivers were chosen to sample juvenile Alabama Sh...

American shad is an anadromous fish that displays asynchronous ovarian development. In an effort to enhance our understanding of the reproductive cycle of this primitive Teleostei species, and provide better management tools for the Chesapeake fishery, we have conducted studies of its gonadal and hormonal cycles. We developed various assays to measure reproductive endocrine factors including: 1...

Of 13 species of fish recorded as hosts for the acanthocephalan, Tanaorhamphus longirostris (Van Cleave 1913), only two regularly contain mature worms. These are the gizzard shad (Dorosoma cepedianum (Lesueur)) and the threadfin shad (D. petenense (Giinther)). To date, only one species of intermediate host, the calanoid copepod, Diaptomus pallidus Herrick, has been reported. In Caesar Creek Lak...

Animals can be important in nutrient cycling in particular ecosystems, but few studies have examined how this importance varies along environmental gradients. In this study we quantified the nutrient cycling role of an abundant detritivorous fish species, the gizzard shad (Dorosoma cepedianum), in reservoir ecosystems along a gradient of ecosystem productivity. Gizzard shad feed mostly on sedim...