Age and Growth of Perch Perca fluviatilis in Lake Erken

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Age and Growth of Perch (Perca fluviatilis) in
Lake Erken

• Fulfilled by
• Slyotova Ekaterina and Mikhailov Ivan
• Supervisor Rahmat Naddafi

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• Perch
• (Perca fluviatilis)

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Perch as a representative of percids

• Predator in the lakes with high water
  transparency
• Dominant in moderately eutrophicated lakes
• Looses in foraging ability in severely
  eutrophicated waters

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The aim of our research

• To compare the age structure and growth of
  P.fluviatilis populations exposed to different
  fish densities in the Lake Erken basins

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H y p o t h e s i s

• Fish densities have negative effect on perch
  growth

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• S 24 km²
• Depth (mean) 9 m
• Depth (max) 21 m

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Standard Length (SL)
Fork Length (FL)
Total Length (TL)
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Opercular bone
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• Total radius
• Annual ring radius

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The dependence between total length (TL) and the
size of opercular bone
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R E S U L T S
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Coexistence of roach and ruffe species has
negative impact on condition factor of perch
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Factors influencing the growth of perch

• Intraspecific competition
• Interspecific competition
• Temperature differences
• Predation
• Water quality