Shift happens: Evaluating the ability of autumn stocked walleye Sander vitreus to shift to natural prey

Piscivorous predators at the apex of aquatic food webs are thought to exhibit foraging behaviours that depend on environmental conditions. Walleye (Sander vitreus), for example, is a freshwater predator that is most active under low light conditions. This study examined walleye resource use and swimming activity across lakes located in northwestern Ontario representing a gradient of water transparency. Muscle glycolytic potential, an index of swimming activity, was estimated by the activity of the enzyme lactate dehydrogenase (LDH). We show that walleye white muscle LDH activity increased with lake water transparency, but that this relationship is not determined by the use of nearshore resources, estimated from δ13C stable isotope signatures, or by prey abundance. On the other hand, walleye muscle LDH activity decreased with increasing prey size, and prey size was larger in lakes of low water transparency. These results support a positive relationship between water transparency and swimming activity in walleye, with prey size as an important factor contributing to this effect.

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Fishery discards do not compensate natural prey shortage in Northern gannets from the English Channel

Biological Conservation ◽

10.1016/j.biocon.2019.05.040 ◽

2019 ◽

Vol 236 ◽

pp. 375-384 ◽

Cited By ~ 3

Author(s):

Tangi Le Bot ◽

Amélie Lescroël ◽

Jérôme Fort ◽

Clara Péron ◽

Olivier Gimenez ◽

...

Keyword(s):

English Channel ◽

Natural Prey ◽

Fishery Discards

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Blue protein with red fluorescence

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1525622113 ◽

2016 ◽

Vol 113 (41) ◽

pp. 11513-11518 ◽

Cited By ~ 15

Author(s):

Swagatha Ghosh ◽

Chi-Li Yu ◽

Daniel J. Ferraro ◽

Sai Sudha ◽

Samir Kumar Pal ◽

...

Keyword(s):

Uv Radiation ◽

Molecular Basis ◽

Spectral Properties ◽

Fluorescent Proteins ◽

Protein A ◽

Sander Vitreus ◽

Ligand Complex ◽

Red Fluorescence ◽

Golden Yellow ◽

Fish Mucus

The walleye (Sander vitreus) is a golden yellow fish that inhabits the Northern American lakes. The recent sightings of the blue walleye and the correlation of its sighting to possible increased UV radiation have been proposed earlier. The underlying molecular basis of its adaptation to increased UV radiation is the presence of a protein (Sandercyanin)–ligand complex in the mucus of walleyes. Degradation of heme by UV radiation results in the formation of Biliverdin IXα (BLA), the chromophore bound to Sandercyanin. We show that Sandercyanin is a monomeric protein that forms stable homotetramers on addition of BLA to the protein. A structure of the Sandercyanin–BLA complex, purified from the fish mucus, reveals a glycosylated protein with a lipocalin fold. This protein–ligand complex absorbs light in the UV region (λmax of 375 nm) and upon excitation at this wavelength emits in the red region (λmax of 675 nm). Unlike all other known biliverdin-bound fluorescent proteins, the chromophore is noncovalently bound to the protein. We provide here a molecular rationale for the observed spectral properties of Sandercyanin.

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Keanekaragaman Serangga Sebagai Pakan Alami Katak Tegalan (Fejervarya Limnocharis, Gravenhorst) pada Ekosistem Sawah di Desa Panggungharjo, Kecamatan Sewon, Kabupaten Bantul

Journal of Tropical Biodiversity and Biotechnology ◽

10.22146/jtbb.12723 ◽

2016 ◽

Vol 1 (1) ◽

pp. 1

Author(s):

Farid Kuswantoro ◽

R.C. Hidayat Soesilohadi

Keyword(s):

Plant Growth ◽

Paddy Field ◽

Survey Method ◽

Growth Stages ◽

Insect Diversity ◽

Insect Prey ◽

Natural Prey ◽

Plant Growth Stages ◽

Generative Phase ◽

Fejervarya Limnocharis

Paddy field was a dynamic and biodiversity rich ecosystems. Insect diversity in paddy field ecosystem was infected by paddy plant growth stages. Grass frog (Fejervarya limnocharis) ate insects as their natural prey. Insect population dynamics during vegetative, generative and reproductive stage of paddy plants infected F. limnocharis natural prey. This research aims were to study insect diversity and F. limnocharis insect prey diversity of vegetative, reproductive and generative paddy plant growth stages at Panggungharjo village, Sewon, Bantul. Insect sampling was conducted by direct survey method while F. limnocharis collection conducted by Visual Encounter Survey (VES) method. Ninety eight insect species from 51 different families and nine orders of insect were found. The orders were Coleoptera, Diptera, Hymenoptera, Odonata, Orthoptera, Dictyoptera, Dermaptera, Hemiptera and Lepidoptera. Stomachs analysis indicated F. limnocharis ate nine insect orders. The orders were Coleoptera, Diptera, Hymenoptera, Orthoptera, Dictyoptera, Dermaptera, Hemiptera, Lepidoptera and Isoptera. Most commonly insect prey in vegetative, reproductive and generative phase paddy growth stage were the members of the Order Coleoptera, Family Acrididae (Orthoptera) and Family Formicidae (Hymenoptera) respectively. This study concluded F. limnocharis main natural prey was the easily found and easily perceived insects.

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Consistent patterns of maturity and density-dependent growth among populations of walleye (Sander vitreus): application of the growing degree-day metric

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f10-041 ◽

2010 ◽

Vol 67 (7) ◽

pp. 1057-1067 ◽

Cited By ~ 66

Author(s):

Paul A. Venturelli ◽

Nigel P. Lester ◽

Terry R. Marshall ◽

Brian J. Shuter

Keyword(s):

Growth Rate ◽

Explanatory Power ◽

Management Strategies ◽

Fold Increase ◽

Fish Growth ◽

Growing Degree Days ◽

Sander Vitreus ◽

Degree Days ◽

Regional Management ◽

Dependent Growth

Growing degree-days (GDD, °C·days) are an index of ambient thermal energy that relates directly to an ectotherm’s cumulative metabolism but is rarely used to describe growth and development in fish. We applied GDD to length and maturity data from 416 populations of walleye ( Sander vitreus ) from Ontario and Quebec, Canada (mean annual GDD = 1200 to 2300 °C·days). On average, males matured after they had experienced 6900 °C·days and reached 350 mm total length (L) (n = 77 populations), and females matured after 10 000 °C·days and at 450 mm L (n = 70). Across 143 populations, GDD accounted for up to 96% of the variation in the length of immature walleye but also revealed a twofold difference in growth rate that was indicative of variation in food availability. When applied to data from eight populations in which walleye abundances have changed dramatically over time, GDD revealed a 1.3-fold increase in immature growth rate when abundance was low compared with when it was high. Our results both demonstrate the explanatory power of GDD with respect to fish growth and maturity and inform the development of regional management strategies for walleye.

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