Nutritional Implications of Surface Feeding by Gizzard Shad (Dorosoma cepedianum) on Insect Remains in an Ohio Reservoir

1977 ◽  
Vol 34 (2) ◽  
pp. 269-273 ◽  
Author(s):  
Patricia A. King ◽  
Thomas E. Wissing ◽  
Edward J. De Villez ◽  
Michael J. Chimney ◽  
William B. Randall Jr.

On six occasions during July and August 1975, surface feeding by schools of adult gizzard shad (Dorosoma cepedianum) on insect remains was observed in Acton Lake, Ohio. Proteinases in the digestive tract presumably hydrolyze the protein in the insect cuticle. The chitin component of the cuticle also has nutritive value, as significant chitinase activity was demonstrated in extracts of gizzard mucosa, hepatopancreas, and intestinal ceca. Values were comparable to activities observed in other fish species. Chitinolytic system activity was not demonstrated.The mean caloric equivalents of the chironomid and chaoborid exuviae and winged ants in surface debris were 5355, 4363, and 6059 cal/g ash-free dry wt, respectively. Ingestion of insect remains by this forage species could accelerate the return of energy and nutrients in these materials to higher trophic levels.

2007 ◽  
Vol 64 (12) ◽  
pp. 1805-1815 ◽  
Author(s):  
Gene W Kim ◽  
Alpa P Wintzer ◽  
Trisha K Menker ◽  
Roy A Stein ◽  
John M Dettmers ◽  
...  

Gizzard shad (Dorosoma cepedianum) population characteristics vary with lake productivity, competing with and providing prey for sport fishes. Because age-0 gizzard shad (>30 mm total length) are facultative detritivores, they can link benthic energy, carbon, and nutrients to pelagic food webs. To determine how age-0 gizzard shad success varies along a detritus-quality gradient, we completed a 15-day laboratory experiment in which age-0 gizzard shad fed lake sediment and starved gizzard shad both suffered high mortality, whereas fish fed zooplankton grew and survived well. This suggested that detritus alone is insufficient to ensure gizzard shad growth and survival. When sediment quality was high in outdoor mesocosms, density-dependent factors led to rapid growth only at low fish density and high-quality sediments; however, survival generally increased with sediment quality, regardless of gizzard shad density. In four small reservoirs, annual growth of gizzard shad increased with sediment quality. Collectively, our findings suggest that detritus quality ultimately can contribute to regulation of community and ecosystem productivity, mediated by its influence on gizzard shad biomass available for trophic transfer to gape-limited predators (i.e., piscivorous fish). This role of gizzard shad can link higher trophic levels in aquatic food webs to allochthonous detritus subsidies from the surrounding watershed.


2021 ◽  
Vol 166 ◽  
pp. 112172
Author(s):  
Tiphaine Mille ◽  
Amaëlle Bisch ◽  
Nathalie Caill-Milly ◽  
Pierre Cresson ◽  
Jonathan Deborde ◽  
...  

2011 ◽  
Vol 27 (4) ◽  
pp. 287-297 ◽  
Author(s):  
Walt Godwin ◽  
Michael Coveney ◽  
Edgar Lowe ◽  
Lawrence Battoe

2007 ◽  
Vol 42 (2) ◽  
pp. 101-110 ◽  
Author(s):  
Eugene T. Georgiades ◽  
Douglas A. Holdway

Abstract An examination of acetylcholinesterase (AChE), citrate synthase (CS) and lactate dehydrogenase (LDH) activities in the brains of a range of fish species, occupying different trophic levels, is useful to investigate the full extent of the effects of sublethal or pulse exposures to pesticides. This investigation explores the optimization of microplate procedures for AChE, CS and LDH measurements in the brain tissue of species commonly used in laboratory investigations and those common to Canadian watersheds. A microplate assay was optimized for the measurement of AChE in the brain homogenates of seven fish species. The critical aspects of this assay requiring optimization were pH, substrate concentration and tissue dilution. Incubation with specific cholinesterase inhibitors indicated that enzymatic activity in the brain homogenates of each species was attributed to AChE only. Microplate assays were also optimized for the measurement of the metabolic enzymes, CS and LDH, in the brain homogenates of six fish species. For these assays, low interspecies variability was exhibited between optimized factors including pH, substrate, chromogen and cofactor concentrations. For each assay optimized, enzyme activities in the brain homogenates were stable for 2 to 3 hours post-thaw. Results from the present study will aid future ecotoxicological investigations of the potential impacts of AChE inhibition on neuronal glucose metabolism.


The tapeta lucida of three species of teleosts were examined to determine the composition of the reflecting material. The fishes were bay anchovy Anchoa mitchilli (Engraulidae), gizzard shad Dorosoma cepedianum (Clupeidae) and pigfish Orthopristes chrysopterus (Haemulidae). The tapetum of each species was situated in the pigment epithelium of the eye. That of the pigfish contained triglycerides identified as chiefly glyceryl tridocosahexaenoate. A reduced pteridine, 7, 8-dihydroxanthopterin, occurred in the tapetum of the gizzard shad. Guanine occurred in the tapetum of the bay anchovy. The tapetum of the shad contained brightly reflecting particles about 0.5 μm in diameter There were 10.8 mg of dihydroxanthopterin in the tapetum of a shad (total body length 23 cm) and 0.46 mg of guanine in the tapetum of an anchovy (total body length 9 cm). This is the first report of a pteridine acting as a retinal reflector in vertebrates. Various aspects of retinal reflectors of teleosts are discussed and their variety and common characteristics commented upon.


2014 ◽  
Vol 74 (3) ◽  
pp. 588-596 ◽  
Author(s):  
RML Silveira ◽  
B Weiss

We analysed the germination of seeds after their passage through the digestive tract of small floodplain fishes. Samples were collected in five open flooded fields of the northern Pantanal in March 2011. All fishes were sacrificed and their intestinal contents were removed. The fecal material was weighed and stored at 4°C in a GF/C filter wrapped in aluminum foil. The material was then transferred to a receptacle containing sterilised soil from the sampling area. The fecal samples were kept in a germination chamber for 68 days and then transferred to a greenhouse for another 67 days. We collected a total of 45 fish species and 1014 individuals which produced a total amount of 32g of fresh fecal mass and 11 seedlings. We were able to identify six seedlings: two Banara arguta, two Steinchisma laxa, one Hymenachne amplexicaulis and one Luziola sp.. The fish species that produced samples with seedlings were Astyanax assuncionensis, Metynnis mola, Plesiolebias glaucopterus, Acestrorhyncus pantaneiro and Anadoras wendelli. With the exception of B. arguta the remaining plant species and all fish species were not known to be associated with the seed dispersal process of these plants. We found a ratio of 0.435 seedlings.g–1 of fresh fecal material, which is 100 times higher than the amount of seedlings encountered in fresh soil mass (92,974 grams) in seed bank studies conducted in the same study area. In particular, Astyanax assuncionensis and Metynnis mola were among the most frequent and most abundant fish taxa in the area. Together with the high seed concentration in the fish fecal material, this evidence allows us to conclude that such fish species may play an important role in seed dispersal in the herbaceous plants of the Pantanal.


2000 ◽  
Vol 57 (6) ◽  
pp. 1113-1119 ◽  
Author(s):  
James C Smoot ◽  
Robert H Findlay

Measuring digestive enzyme and surfactant activities tested specialization of gizzard shad (Dorosoma cepedianum) digestive physiology to a detritivorous feeding strategy. Digestive enzyme activity was measured in adult and larval gizzard shad using fluorescently labeled artificial substrates. Surfactant activity in gizzard shad was measured by comparing gut juice drop diameters over a range of dilutions. Enzyme activity in the ceca region of adult gizzard shad was high for esterase, beta-glucosidase, lipase, and protease. Enzyme activity was lower in posterior intestine sections than in anterior intestine sections, although protease activity remained high for the greatest distance in the intestine. Micelles were detected in adult gizzard shad gut juice, and surfactant activity was greatest in the ceca region. Larval gizzard shad protease activity was similar to that of adult fish, and surfactants were below their critical micelle concentration. Gizzard shad coupled digestive physiology with gut anatomy to obtain nutrients from detritus, and these adaptations may explain elevated growth rates observed in these fish when they are planktivorous.


1996 ◽  
Vol 15 (10) ◽  
pp. 1752-1759 ◽  
Author(s):  
Alan S. Kolok ◽  
James N. Huckins ◽  
Jimmie D. Petty ◽  
James T. Oris

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