Mechanisms of invasive gibel carp (Carassius gibelio) competitive dominance over native crucian carp (Carassius carassius)

Sandip Dnyaneshwar TAPKIR

Doctoral thesis

Mechanisms of invasive Prussian carp (Carassius gibelio) dominance over native crucian carp (C. carassius)

Abstract:

This thesis explores the reasons behind the decline of the native crucian carp (Carassius carassius) in European waters, emphasizing the critical endangerment due to resource competition with invasive gibel carp (Carassius gibelio). Through a combination of field studies (Czech and Swedish water bodies) and controlled laboratory experiments, the research compares growth patterns, fish condition, and resource utilization between native and invasive species. The findings reveal that C. gibelio exhibits significantly greater growth increments and more efficient to use of food resources. Additionally, trophic niche utilization and stable isotope analysis show how C. gibelio gains a competitive advantage by exploiting plant material unused by C. carassius. The thesis also explores the impacts of eutrophication on native species, focusing on how nutrient enrichment affects growth rate and competitive interaction between the species. This research supports the hypothesis that the introduction and spread of invasive C. gibelio contribute to the decline of C. carassius in European waters and highlights the need to address eutrophication and invasive species mitigation in freshwater conservation strategies.

Abstract:

This thesis explores the reasons behind the decline of the native crucian carp (Carassius carassius) in European waters, emphasizing the critical endangerment due to resource competition with invasive gibel carp (Carassius gibelio). Through a combination of field studies (Czech and Swedish water bodies) and controlled laboratory experiments, the research compares growth patterns, fish condition, and resource utilization between native and invasive species. The findings reveal that C. gibelio exhibits significantly greater growth increments and more efficient to use of food resources. Additionally, trophic niche utilization and stable isotope analysis show how C. gibelio gains a competitive advantage by exploiting plant material unused by C. carassius. The thesis also explores the impacts of eutrophication on native species, focusing on how nutrient enrichment affects growth rate and competitive interaction between the species. This research supports the hypothesis that the introduction and spread of invasive C. gibelio contribute to the decline of C. carassius in European waters and highlights the need to address eutrophication and invasive species mitigation in freshwater conservation strategies.

Keywords

Interspecific interactions, Invasive species, Resource competition, Native species, Trophic position, Eutrophication, Vacant niche, Crucian carp, Gibel carp, Ecology, Ecological interactions, Coexistence

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 11. 10. 2024

Obhajoba závěrečné práce

• Vedúci: RNDr. Marek Šmejkal, Ph.D.

UNIVERSITY OF SOUTH BOHEMIA IN ČESKÉ BUDĚJOVICE

Faculty of Science

Doctoral programme / odbor:
Limnology / Limnology