The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (dorosoma cepedianum)

An open-water planktivore, the gizzard shad (Dorosoma cepedianum), can drive complex interactions among fish and zooplankton in Ohio reservoirs. In Kokosing Lake, crustacean zooplankton density declined to near zero immediately after larval gizzard shad abundance peaked during 1987 and 1988. This decline can be attributed to increased death rates, due to predation, and to reduced number of eggs per cladoceran. In an enclosure/exclosure experiment, young-of-year gizzard shad at lake densities significantly reduced density of crustacean zooplankton and rotifers within 2 wk. In addition, phytoplankton that were edible to zooplankton were reduced in enclosures, likely due to a combination of direct herbivory by gizzard shad and reduced nutrient availability due to uptake by the growing gizzard shad. Gizzard shad not only directly influenced zooplankton via predation, they also indirectly affected zooplankton by reducing phytoplankton abundance. Because larval bluegill (Lepomis macrochira) migrated to the limnetic zone during or shortly after the zooplankton decline, food available to these zooplanktivorous larvae, as well as their ultimate recruitment, was reduced with gizzard shad. Through direct (i.e. predation) and indirect (i.e. influencing algal abundance) pathways, gizzard shad can drive zooplankton to extinction, thereby reducing recruitment of other fishes and controlling community composition.

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Capture Probability: The Role of Zooplankter Escape in the Selective Feeding of Planktivorous Fish

Journal of the Fisheries Research Board of Canada ◽

10.1139/f78-215 ◽

1978 ◽

Vol 35 (10) ◽

pp. 1370-1373 ◽

Cited By ~ 194

Author(s):

Ray W. Drenner ◽

J. Rudi Strickler ◽

W. John O'Brien

Keyword(s):

Key Words ◽

Capture Probability ◽

Planktivorous Fish ◽

Gizzard Shad ◽

Conditional Probabilities ◽

Dorosoma Cepedianum ◽

Selective Feeding ◽

Feeding Selectivity ◽

Feeding Experiments

The conditional probabilities (P3) of being captured by a simulated fish-suction intake ranged from P = 0.76 to P = 0.96 for cladocerans and from P = 0.07 to P = 0.28 for copepods. Gizzard shad (Dorosoma cepedianum) feeding experiments confirmed that these differential capture probabilities can result in an apparent planktivore feeding selectivity for cladoceran zooplankters. Key words: capture probability, zooplankter escape, planktivore feeding selectivity, gizzard shad

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Improvements in water quality following biomanipulation of gizzard shad (Dorosoma cepedianum) in Lake Denham, Florida

Lake and Reservoir Management ◽

10.1080/07438141.2011.609633 ◽

2011 ◽

Vol 27 (4) ◽

pp. 287-297 ◽

Cited By ~ 8

Author(s):

Walt Godwin ◽

Michael Coveney ◽

Edgar Lowe ◽

Lawrence Battoe

Keyword(s):

Water Quality ◽

Gizzard Shad ◽

Dorosoma Cepedianum

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Reflecting materials in the eyes of three teleosts, Orthopristes chrysopterus, Dorosoma cepedianum and Anchoa mitchilli

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1973.0028 ◽

1973 ◽

Vol 184 (1074) ◽

pp. 15-27 ◽

Cited By ~ 19

Keyword(s):

Body Length ◽

Pigment Epithelium ◽

Total Body Length ◽

Gizzard Shad ◽

Dorosoma Cepedianum ◽

Anchoa Mitchilli ◽

First Report ◽

Total Body ◽

Bay Anchovy

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.

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Digestive enzyme and gut surfactant activity of detritivorous gizzard shad (Dorosoma cepedianum)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-036 ◽

2000 ◽

Vol 57 (6) ◽

pp. 1113-1119 ◽

Cited By ~ 15

Author(s):

James C Smoot ◽

Robert H Findlay

Keyword(s):

Enzyme Activity ◽

Protease Activity ◽

Feeding Strategy ◽

Digestive Enzyme ◽

Artificial Substrates ◽

Gizzard Shad ◽

Dorosoma Cepedianum ◽

Digestive Physiology ◽

Protease Enzyme ◽

Surfactant Activity

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.

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