|
|
Biogeography, phylogeny, ecology and systematics of epigean freshwater Amphipoda in the Carpathian arc and beyond
Copilas-Ciocianu, Denis ; Petrusek, Adam (advisor) ; Väinölä, Risto (referee) ; Trontejl, Peter (referee)
3 ABSTRACT Freshwateramphipodsarepoordispersersduetothefragmentarynatureoftheir habitat,benthiclife-styleandlackofresistantpropagules.Consequently,mostspeciesare narrowlyendemic,andwidespreadmorphospeciesconsistofnumerousdivergentlineages. Assuch,thesepatternsareconsideredrelict, mainlyreflectinghistoricalratherthan contemporaryfactors.TheCarpathian Mountainsunderwentadramaticgeomorphological evolutionduringthelast20millionyears,risingfromtheParatethysSeathroughaseriesof islandsthateventuallycoalescedintooneofthelongest mountainchainsinEurope. Moreover,these mountainsandsurroundingbasinsareinhabitedbyaubiquitousand diverseamphipodfauna,providinganidealsettingfortestinghistoricalbiogeographical hypotheses.OurresultshaveshownthatinthesouthernhalfoftheCarpathians,montane Gammarus taxadisplayfragmentedandallopatricdistributionpatterns whilelowland speciesbelongingtothegeneraNiphargus andSynurella are mostlysympatricand widespreadoverlargedistances.Subsequent molecularinvestigationsrevealedthatthe patchydistributionofG.fossaruminthewesternandsouthwesternCarpathianshaslikely resultedfromthebreakupofaformerlycontiguouslandmass16 millionyearsago, suggestingthatgeologicalsubsidencecanplayanimportantroleinshapingbiogeographical patterns. Moreover,the WesternCarpathianlineagesineasternCzechiaandSlovakiaare...
|
|
|
Diversity of freshwater epigean amphipods
Rutová, Tereza ; Petrusek, Adam (advisor) ; Sacherová, Veronika (referee)
Gammarids, the most diverse group of Amphipoda are present in marine, brackish and fresh waters. In freshwater there are forms inhabiting the surface (epigean) and underground (hypogean) habitats and this thesis will be focused on epigean freshwater groups. Freshwater gammarids inhabit the continental waters of all continents, but the highest species diversity is evident in the Palearctic region. However they cannot be found in the surface waters of the tropical regions. These amphipods are characterized by the absence of any resistant or larval stages. Thus the present diversity and distribution reflects historical events like the fluctuation in sea levels, orogeny or period of glaciation from the Paleocene to the present. The goal of this thesis will be to summarize which processes and in which period the diversity of freshwater epigean amphipods were affected. One part of this thesis is dedicated to the families occurring in Australia (Chiltonidae), New Zealand (eg. Phreathogammaridae) and the North and the South America (Hyalellidae). The main focus is on family Gammaridae in which according to recent studies should include lineages occurring in the entire Palearctis including endemic groups in the Lake Baikal and across the Ponto-Caspian area. In the history of the development of gammarids...
|
|
|
Biogeography, phylogeny, ecology and systematics of epigean freshwater Amphipoda in the Carpathian arc and beyond
Copilas-Ciocianu, Denis ; Petrusek, Adam (advisor) ; Väinölä, Risto (referee) ; Trontejl, Peter (referee)
3 ABSTRACT Freshwateramphipodsarepoordispersersduetothefragmentarynatureoftheir habitat,benthiclife-styleandlackofresistantpropagules.Consequently,mostspeciesare narrowlyendemic,andwidespreadmorphospeciesconsistofnumerousdivergentlineages. Assuch,thesepatternsareconsideredrelict, mainlyreflectinghistoricalratherthan contemporaryfactors.TheCarpathian Mountainsunderwentadramaticgeomorphological evolutionduringthelast20millionyears,risingfromtheParatethysSeathroughaseriesof islandsthateventuallycoalescedintooneofthelongest mountainchainsinEurope. Moreover,these mountainsandsurroundingbasinsareinhabitedbyaubiquitousand diverseamphipodfauna,providinganidealsettingfortestinghistoricalbiogeographical hypotheses.OurresultshaveshownthatinthesouthernhalfoftheCarpathians,montane Gammarus taxadisplayfragmentedandallopatricdistributionpatterns whilelowland speciesbelongingtothegeneraNiphargus andSynurella are mostlysympatricand widespreadoverlargedistances.Subsequent molecularinvestigationsrevealedthatthe patchydistributionofG.fossaruminthewesternandsouthwesternCarpathianshaslikely resultedfromthebreakupofaformerlycontiguouslandmass16 millionyearsago, suggestingthatgeologicalsubsidencecanplayanimportantroleinshapingbiogeographical patterns. Moreover,the WesternCarpathianlineagesineasternCzechiaandSlovakiaare...
|
|
|
Ecological interactions and niche differentiation of coexisting freshwater amphipods
Bystřický, Pavel Karel ; Petrusek, Adam (advisor) ; Pařil, Petr (referee)
Freshwater amphipods are ecologically important crustacean group. They act mainly as shredders of detritus in fast-running and cold waters, contributing to the nutrient cycles. Ecological interactions within this group are interesting especially in connection with a considerable degree of cryptic diversity, as well as due to contacts of invasive and native species. This thesis deals with so far studied interactions between syntopic species or lineages, especially those that may affect coexistence or competitive exclusion, such as: different levels of selective predation, ecologically significant differences in morphology or behavior, varying degrees of aggressiveness or intraguild predation, and differences in habitat preferences or resource use ability. Due to the large number of newly discovered cryptic lineages, only little effort has been invested to studies of their ecological interactions. For the time being, research has been limited to sexual interactions (potential reproductive interference or hybridization), differences in habitat preferences, or infestation rates by parasites. It is worth mentioning that only a few lineages have been explored in this way, and the lessons learned from these few works cannot yet be generalized. In my work, I focus on cryptic species complexes in which at...
|
|
|
Diversity of freshwater epigean amphipods
Rutová, Tereza ; Petrusek, Adam (advisor) ; Sacherová, Veronika (referee)
Gammarids, the most diverse group of Amphipoda are present in marine, brackish and fresh waters. In freshwater there are forms inhabiting the surface (epigean) and underground (hypogean) habitats and this thesis will be focused on epigean freshwater groups. Freshwater gammarids inhabit the continental waters of all continents, but the highest species diversity is evident in the Palearctic region. However they cannot be found in the surface waters of the tropical regions. These amphipods are characterized by the absence of any resistant or larval stages. Thus the present diversity and distribution reflects historical events like the fluctuation in sea levels, orogeny or period of glaciation from the Paleocene to the present. The goal of this thesis will be to summarize which processes and in which period the diversity of freshwater epigean amphipods were affected. One part of this thesis is dedicated to the families occurring in Australia (Chiltonidae), New Zealand (eg. Phreathogammaridae) and the North and the South America (Hyalellidae). The main focus is on family Gammaridae in which according to recent studies should include lineages occurring in the entire Palearctis including endemic groups in the Lake Baikal and across the Ponto-Caspian area. In the history of the development of gammarids...
|
guest ::
