Kljubovanje vodnemu toku pri površinskih in podzemeljskih populacijah vodnih osličkov

magistrsko delo

Alenka Mihelčič (Author), Cene Fišer (Reviewer), Peter Trontelj (Mentor), Peter Trontelj (Thesis defence commission member), Žiga Fišer (Thesis defence commission member), Cene Fišer (Thesis defence commission member), Janko Božič (Thesis defence commission member), Žiga Fišer (Co-mentor)

Abstract

Podzemeljsko okolje in podzemeljske živali so zaradi ekstremnih razlik v okoljskih dejavnikih med podzemeljem in površjem odličen modelni sistem za preučevanje ekološke speciacije, tj. nastanka novih vrst zaradi divergentne naravne selekcije. Enakonožni rak vodni osliček, Asellus aquaticus, je podzemlje naselil večkrat neodvisno in ima še živeče površinske populacije. Med površinskimi in podzemeljskimi populacijami vodnega oslička genskega pretoka praktično ni, zato mora med njimi obstajati reproduktivna izolacija. Pri dveh površinsko-podzemeljskih parih populacij vodnih osličkov (Planinsko polje-Pivkin rokav Planinske jame, Cerkniško polje-Rakov rokav Planinske jame) smo izmerili sposobnost kljubovanja vodnemu toku in preverili ali bi ta lastnost lahko učinkovala kot reproduktivna bariera. Kritično hitrost vodnega toka (tj. hitrost toka, pri kateri oslička odplavi) smo izmerili 160 vodnim osličkom, po 20 samcem in 20 samicam iz vsake populacije. Podzemeljski oslički iz Pivkinega rokava so vzdržali hitrejši tok kot površinski oslički s Planinskega polja, med podzemeljskimi oslički iz Rakovega rokava in površinskimi oslički s Cerkniškega polja pa ni bilo razlike v kritični hitrosti vodnega toka. Obe podzemeljski populaciji sta imeli v primerjavi s površinskima večjo napovedljivost kritične hitrosti toka pri posamičnih osebkih. Razlika med obema podzemeljskima populacijama bi lahko bila posledica različnih hidroloških razmer v obeh rokavih Planinske jame. Razlike v sposobnosti kljubovanja vodnemu toku med ekomorfoma so verjetno premajhne, da bi lahko delovale kot reproduktivna bariera. Da bi ugotovili, ali so izmerjene razlike ključne za to, da se podzemeljski oslički v podzemlju obdržijo, površinski pa ne, bi morali izmeriti še hitrosti vodnega toka v naravnem habitatu populacij.

Keywords

ekološka speciacija;reproduktivna izolacija;vedenje;kljubovanje vodnemu toku;podzemna favna;

Data

Language:	Slovenian
Year of publishing:	2018
Typology:	2.09 - Master's Thesis
Organization:	UL BF - Biotechnical Faculty
Publisher:	[A. Mihelčič]
UDC:	595.373(043.2)
COBISS:	4661583
Views:	1222
Downloads:	621
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Resistance of surface and subterranean waterlice populations to water curent
Secondary abstract:	Due to the extreme differences in environmental factors between subterranean and surface environments, subterranean habitats and animals therein are an excellent model system for studying ecological speciation, i.e. the origin of new species as side effect of divergent natural selection. The freshwater isopod crustacean waterlouse, Asellus aquaticus, has colonised the underground several times independently and has still living surface populations. There is practically no gene flow between surface and subterranean populations, suggesting a reproductive isolation must exist among them. In two surface-subterranean population pairs of waterlice (Planina Polje-Pivka River in Planina Cave, Cerknica Polje-Rak River in Planina Cave), we measured the ability of individuals to resist water current and checked if this trait could act as a reproductive barrier. Critical water current velocity (i.e. the velocity of water current at which waterlouse was washed away) was measured for 160 individuals, 20 males and 20 females from each population. The subterranean waterlice from Pivka River resisted a faster water current than the surface waterlice from Planina Polje, but no difference in the critical water current velocity was found between the subterranean waterlice from Rak River and the surface waterlice from Cerknica Polje. Individuals of both subterranean populations also had a higher predictability of the critical water current velocity compared to surface individuals. We assume that differences between both subterranean populations may be a consequence of different hydrology of Pivka and Rak River in Planina Cave. The differences between ecomorphs are probably too small to function as a reproductive barrier. To determine whether the measured differences are crucial for keeping the subterranean waterlice in the underground and washing out the surface waterlice, water current velocity should be measured in the natural habitat of these populations.
Secondary keywords:	ecological speciation;reproductive isolation;behaviour;resistance to water current;subterranean fauna;
Type (COBISS):	Master's thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. Ljubljana, Biotehniška fak.
Pages:	IX, 39, [3] str.
ID:	10918718