Mikrostanišna i mikrotrofička diferencijacija ekoloških niša zelenih žaba (Ranidae: Pelophylax esculentus complex) u riparijalnim područjima Južnog Banata, Srbija
Microhabitat and microtrophic differentiation of ecological niches of green frogs (Ranidae: Pelophylax esculentus complex) in riparian areas of South Banat, Serbia
Author
Breka, KatarinaMentor
Stamenković, SrđanCommittee members
Krizmanić, ImreVukov, Tanja
Penezić, Aleksandra
Stupar, Miloš
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Show full item recordAbstract
elene žabe iz Pelophylax esculentus kompleksa su akvatične, sintopijske i gregarne žabe
širokog rasprostranjenja sa izraženom ulogom u ekosistemima koje naseljavaju. Iako se na teritoriji
Srbije i susednih zemalja zelene žabe istražuju u kontinuitetu već više od sto godina, saznanja o
njihovoj ekologiji i prostornoj integraciji populacija su malobrojna posebno u delu areala kompleksa
gde se javljaju populacioni sistemi sa sva tri taksona u sintopiji. U okviru ove teze urađena je
parametrizacija mikrostanišne i mikrotrofičke niše zelenih žaba iz Pelophylax esculentus kompleksa na
području Južnog Banata kao i analiza prostorne integracije populacija sa analizom rizika izumiranja.
Dodatno, analizirane su epibiontske zajednice kože žaba i kondicioni status sva tri taksona na svakom
od lokaliteta. Na kraju, urađena je sintetska reevaluacija lokalnog konzervacionog statusa na
istraživanom području.
Jedinke su sakupljane na tri lokaliteta u Južnom Banatu koji se razlikuju po svojim
hidrološki...m, orografskim i stanišnim karakteristikama ali i po stepenu antropogenog uticaja. Jedinke su
identifikovane na osnovu standardnih mera za analizu varijabilnosti morfoloških karaktera (6
kvalitativnih i 8 kvantitativnih) uz adekvatnu statističku obradu i validaciju nezavisnom grupom
uzoraka identifikovanih genetičkim markerima. Na taj način je od ukupno 317 analiziranih žaba
identifikovano 63 jedinki P. ridibundus, 29 jedinki P. lessonae i 225 jedinki P. esculentus pri čemu je
konstatovano da se korišćenjem morfoloških karaktera može na brz i ekonommičan način uraditi
dovoljno pouzdana identifikacija taksona unutar Pelophylax esculentus kompleksa. Kondicioni status
jedinki je procenjen korišćenjem rezidualnog kondicionog indeksa koji predstavlja uobičajenu metodu
u batrahologiji. Parentalne vrste su imale bolju telesnu kondiciju u odnosu na hibridni takson a sva tri
taksona su generalno lošiju telesnu kondiciju imale na lokalitetu koji je pod najvećim antropogenim
pritiskom. Materijal za trofičku analizu je prikupljen neinvazivnom tehnikom ispiranja želuca a obrasci
trofije su utvrđeni multivarijantnim statističkim metodama i testirani permutacionim analizama prema
različitim scenarijima trofičke diferencijacije. Rezultati su pokazali da zelene žabe istraživanog
područja imaju široke, nespecijalizovane trofičke niše čiji se položaj razlikuje u zavisnosti od lokaliteta
što ukazuje da je ishrana u većoj meri definisana dostupnošću plena i karakteristikama lokaliteta a
manje takson-specifičnim karakteristikama životne forme...
Green frogs from the Pelophylax esculentus complex are aquatic, syntopic and gregarious frogs
of wide distribution with a distinct role in the ecosystems they inhabit. Although green frogs have been
continuously studied on the territory of Serbia and neighbouring countries for more than a hundred
years, knowledge about their ecology and spatial integration of populations is scarce, especially in the
part of the area of the complex where population systems with all three taxa occur in syntopy. In this
work, the parameterisation of the microhabitat and microtrophic niche of green frogs from the
Pelophylax esculentus complex in South Banat and the analysis of the spatial integration of populations
with the analysis of extinction risk were carried out. In addition, frog skin epibiont communities and
body condition of all three taxa at each site were analysed. Finally, a synthetic reassessment of the local
conservation status in the studied area was made.
Specimens were collected from three... sites in southern Banat, differing in their hydrological,
orographic and habitat-typical characteristics, but also in the degree of anthropogenic pressure.
Individuals were identified using standard measures for the analysis of variability of morphological
traits (6 qualitative and 8 quantitative) with appropriate statistical processing and cross-validation by an
independent group of samples identified by genetic markers. In this way, out of 317 frogs analysed, 63
individuals of P. ridibundus, 29 individuals of P. lessonae and 225 individuals of P. esculentus were
identified and it was concluded that the use of morphological traits allows sufficiently reliable taxon
identification within the Pelophylax esculentus complex in a rapid and cost-effective manner. The
condition status of the individuals was assessed using the residual condition index, a method frequently
used in amphibian research. The parental species had better body condition than the hybrid taxon, and
all three taxa generally had lower body condition at the site with the greatest anthropogenic pressure.
Material for trophic analysis was collected using the non-invasive stomach-flushing method, and
trophic niche patterns were identified using multivariate statistical methods and tested by permutation
analyses according to different scenarios of trophic differentiation. The results showed that green frogs
in the study area have broad, non-specialised trophic niches whose position varies with location,
suggesting that diet is determined to a greater extent by prey availability and site characteristics than by
taxon-specific life form characteristics...