Probavna fiziologija u primorskih gušterica (Podarcis siculus R.) s otočića Pod Mrčaru i Pod Kopište

master's thesis

• Title (english): Digestive physiology in the Italian Wall Lizard (Podarcis siculus R.) from islands Pod Mrčaru and Pod Kopište
• Author: Marija Krajnović
• Mentor: Zoran Tadić (mentor)
• Committee member: Zoran Tadić (predsjednik povjerenstva)
• Committee member: Perica Mustafić (član povjerenstva)
• Committee member: Sven Jelaska (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2017-02-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Od oko 6000 vrsta guštera, samo 2% povremeno ili stalno jede bilje. Omnivornost je evoluirala najmanje sedam puta unutar ljuskaša, dok je čista herbivorija relativno rijetka. Na evoluciju biljojednosti utjecali su različiti ekološki čimbenici od kojih važno mjesto zauzima dostupnost hrane. Istraživanja smo proveli na populacijama primorske gušterice (Podarcis siculus) sa otoka Pod Mrčaru i Pod Kopište na kojima je početkom 70-tih godina izveden pokus kompetitivnog isključenja (eng. competitive exclusion). Nakon oko 30 godina, pokazano je da gušterice na Pod Mrčari, koje su potomci gušterica s Pod Kopišta, tijekom ljeta jedu veće količine biljne hrane te da imaju modificirano probavilo koje ukazuje na mogućnost fermentativnog razgrađivanja celuloze pomoću mikroorganizama. U našem istraživanju smo zaključili da su gušteri s Pod Mrčare veći i teži od ishodišne populacije s Pod Kopišta, te da imaju veću relativnu duljinu probavila, pogotovo kod ženki. Također smo zaključili da postoji interakcija između učinka staništa (otoka) i spola na relativne duljine probavila. Potrebna su još mnoga istraživanja ove i drugih vrsta guštera, kako bi bolje razumjeli fiziološke i morfološke promjene povezane s evolucijom herbivornosti i omnivornosti, i kako bi shvatili koji sve ekološki čimbenici mogu utjecati na nastanak herbivornosti kod guštera.

Abstract (english)

Of 6,000 species of lizards, only 2% occasionally or regularly eat plants. Omnivory has evolved at least seven times within squamata, while total herbivory is relatively rare. Evolution of herbivory has been affected by different ecological factors, among the most important ones is the availability of food. An experiment on competitive exclusion was done in 1972. on populations of Italian wall lizard (Podarcis siculus) from the islands of Pod Mrčaru and Pod Kopište. About 30 years after the experiment, lizards on Pod Mrčaru (which are descendants of lizards from Pod Kopište) eat large amounts of plant food especially during the summer, and have modified intestines which indicate the possibility of fermentative degradation of cellulose by microorganisms. We found that the lizards from Pod Mrčaru are larger and heavier than lizards from Pod Kopište, and have greater relative gut lengths, especially females. We also concluded that there is interaction between the effects of habitat and sex on the relative gut lengths. More experiments are needed (on this species and others) in order to better understand the physiological and morphological changes associated with the evolution of herbivory and omnivory, and to realize what ecological factors affect the appearance of herbivory in lizards.

• Keywords: herbivornost; omnivornost; fiziologija; probava; primorska gušterica (Podarcis siculus)
• Keywords (english): herbivory; omnivory; physiology; digestion; Italian wall lizard (Podarcis siculus)
• Language: croatian
• URN:NBN: urn:nbn:hr:217:668219
• Study programme: Title: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra ekologije i zaštite prirode (magistar/magistra ekologije i zaštite prirode)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-04-20 11:52:38