Effect of detritus quality on growth and survival of gizzard shad (Dorosoma cepedianum): potential importance to benthic–pelagic coupling

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.

1994 ◽  
Vol 51 (9) ◽  
pp. 1993-2002 ◽  
Author(s):  
Thomas P. Stahl ◽  
Roy A. Stein

Growth and survival of young-of-year saugeye (Stizostedion vitreum ♂ × S. canadense ♀) (stocked into Ohio reservoirs to create sport fisheries) are probably influenced by prey availability, variations in which may account for historically documented variability in stocking success. Because saugeye switch from a diet of zooplankton to fish once stocked, we sought to determine experimentally if saugeye size and available ichthyoplankton, i.e., larval gizzard shad (Dorosoma cepedianum), affected this switch and whether piscivory improved saugeye growth. In an enclosure experiment, saugeye (33.9 mm TL) immediately switched to piscivory when exposed to ichthyoplankton densities of 20 and 100∙m−3, growing faster when more gizzard shad were available. In another enclosure experiment, saugeye 30–49 mm TL consumed 14-mm gizzard shad. In ponds (N = 4 ponds∙treatment−1) containing zooplankton and chironomids, we compared saugeye growth with and without larval gizzard shad and found, as in the first enclosure experiment, that piscivory improved saugeye growth. Neither saugeye size nor ichthyoplankton density influenced how quickly saugeye switched to piscivory. We conclude that managers should stock saugeye ≥ 30 mm 1–2 wk before peak ichthyoplankton densities to improve saugeye growth and survival by enhancing opportunities for exploitation of young-of-year gizzard shad.


2005 ◽  
Vol 62 (2) ◽  
pp. 333-340 ◽  
Author(s):  
Caroline Anderson ◽  
Gilbert Cabana

We examined the use of the natural abundance of nitrogen stable isotopes (δ15N) as a tracer of anthropo genic perturbations of the nitrogen (N) cycle at the watershed scale in 82 river sites draining 13 watersheds in the St. Lawrence Lowlands in Quebec. Mean δ15N values of aquatic primary consumers varied greatly among sites (+2‰ to +15‰), most of this variation (88%) being attributable to site effects. Variation in δ15N values among functional feeding groups of primary consumers within sites was comparatively lower (<1‰). Within watersheds, δ15N values of primary consumers (and organisms of higher trophic levels) tracked longitudinal changes in the percentage of agricultural area. Overall, the percentage of total watershed area under agriculture explained up to 69% of the variation in mean primary consumer δ15N values. Similar positive correlations were observed for predatory invertebrates and non-piscivorous fish. In general, our results show that δ15N in riverine food webs reacts strongly to spatial patterns in the intensity of N inputs related to agricultural land use.


1993 ◽  
Vol 50 (9) ◽  
pp. 1961-1968 ◽  
Author(s):  
David H. Wahl ◽  
Roy A. Stein

We compared growth, survival, diet, and angler catch of muskellunge (Esox masquinongy), northern pike (E. lucius), and tiger muskellunge (E. masquinongy × E. lucius) through 5 yr after their introduction into three Ohio reservoirs. Muskellunge grew slower than northern pike and tiger muskellunge through the first year but faster than northern pike in subsequent years. Large stocked esocids (180–205 mm) survived better than small ones (145 mm). Survival patterns established through the first fall were maintained through age 5; northern pike survived best, followed by muskellunge and tiger muskellunge. Angler catch reflected differences in survival as well as catchability among taxa. Northern pike were caught at smaller sizes and younger ages than other taxa. Gizzard shad (Dorosoma cepedianum) dominated esocid diets for all taxa and age classes, followed by centrarchids and cyprinids. Prey length consumed increased linearly with esocid length; northern pike selected larger gizzard shad than either muskellunge or tiger muskellunge. These differences in population characteristics among esocids should influence mangement and stocking programs. Whereas northern pike maximize angling opportunities, muskellunge probably will provide trophy fisheries. Although tiger muskellunge can be reared inexpensively, they appear to provide little recreational fishing in return.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.


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

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.


2021 ◽  
Author(s):  
Ruben Ceulemans ◽  
Laurie Anne Myriam Wojcik ◽  
Ursula Gaedke

Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: this loss may hamper ecosystems' ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of climate and human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. Here, we investigate the effects of a nutrient pulse on the resistance, resilience and elasticity of a tritrophic---and thus more realistic---plankton food web model depending on its functional diversity. We compare a non-adaptive food chain with no diversity to a highly diverse food web with three adaptive trophic levels. The species fitness differences are balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occured. Importantly, we found that a more diverse food web was generally more resistant, resilient, and elastic. Particularly, functional diversity dampened the probability of a regime shift towards a non-desirable alternative state. In addition, despite the complex influence of the shape and type of the dynamical attractors, the basal-intermediate interaction determined the robustness against a nutrient pulse. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience and elasticity as functional diversity declines.


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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