Buicu, Florin - Cristea, Doina (szerk.): Satu Mare. Studii şi comunicări. Seria ştiinţele naturii 9. (2008)
Ştiinţele naturii
THE STUDY OF THE TROPHIC SPECTRUM OF SOME BOMBINA VARIEGATA POPULATIONS FROM ARAD COUNTY Sara FERENŢI1,*, Diana CUPŞA1, Nicoleta DIM ANCE. A 2, Maria ANCAU1, Zsolt BATA1 1. University of Oradea, Faculty ofSciences, Department of Biology, Universitarii Str. No1, Oradea 410087 2. University of Oradea, Faculty of History and Geography, Department of Geography, Universitarii Str. No 1, Oradea 410087 * Corresponding author. E-mail:ferenti_sara@yahoo.com Summary. We analysed the trophic spectrum of 154 individuals of Bombina variegata from Arad county, Mădrigeşti locality. The most important preys were the Hymenopteras Formicides, Coleopteras and Dipteras. We can notice the larger larvae consumption in the females' case. In the stomachal contents we also identified besides animal prey, vegetal remains and shed-skin. There is a pozitive connection between the consumption of vegetales and the weight of the terrestrial prey, and a negative one between the consumption of the vegetales and shed-skin. The yellow bellied toad fed mostly terrestrial. Rezumat Studiul spectrului trofic al unor populaţii de Bombina variegata din Judeţul Arad. Am analizat spectrul trofic a 154 de exemplare de Bombina variegata din Judeţul Arad, localitatea Mădrigeşti. Prăzile cele mai importante erau Hymenopterele Formicide, Coleopterele şi Dipterele. Se observă consumul în număr mai mare a larvelor de către femele. In conţinuturile stomacale pe lăngă prăzi de natură animală am mai identificat şi fragmente de vegetale şi exuvie. Există o corelaţie pozitivă între consumul de vegetale şi ponderea prăzilor terestre, respectiv o corelaţie negativă între consumul de vegetale şi de exuvie. Izvoraşii de baltă cu burtă galbenă s-au hrănit majoritar terestru. Introduction Bombina variegata has a stronger connection with the terrestrial environment than the similar species, Bombina bombina (Madej, 1973). It is a species attached to the ecological conditions of the hilly and mountainous areas, being found from 150m upward', but we can sometimes find pure yellow bellied toads at 100m (Madej, 1964). Because of the global decline of amphibians (Wake 1991), it is necessary to take measures in preserving the biodiversity, which can be accomplished through the conservation of the habitats of the amphibians. Food is a very important factor which can provide indicators concerning the state of the environment (Inger&Colwell, 1977), which is necessary in regards to its protection. The feeding of these frogs is dealt with in many specialised articles (Sas et al. 2004b,2005a,2006b, Ghiurcă & Zaharia 2005, Toth et al. 2007). The aim of our study is to analyse the composition of the yellow bellied toads' food, using the results as a very important indicator in the conservation methods of the habitat and thus, the environment. Materials and methods Our study took place in 2006, when we analysed the food composition of 154 Bombina variegata individuals, captured from a habitat near Mădrigeşti locality, Arad county. We colected Satu Mare - Studii şi Comunicări Seria Ştiinţele Naturii Voi IX (2008) pp: 15 - 21 data on several occasions, gathering stomachal contents monthly, starting from May and ending with September. The habitat from which the yellow bellied tods were captured is close to a country road. The puddle is limited by the forest, which offers diverse living conditions. Just because of this the fauna is very diverse, here we can find invertebrates, characteristic to the forest, as well as vertebrates, especially tritons.The depth of the puddle is about 50cm, but this depends on the rain. The surface of the puddle is approximately 5m2. The vegetation is very rich, represented by grassy vegetation and pewter, but the puddle is surrounded by trees and bushes. This is why the bottom of it is covered with a thick layer of silt and decomposed leaves. We used the stomachal flushing method so as not to harm the analysed animals. This method is recommended and suggested by many authors ( Sole et al. 2005, Legier & Sullivan 1979, Opatriny 1980, Griffiths 1986, Ledere & Curtois 1993), because of the low proportion of injured individuals, if it is correctly applied (Sole et al.2005). The samples were preserved in a 4% solution of formaldehyde and identified in the laboratory, using a magnifying glass and scientific literature (Radu & Radu 1967; Chinery, 1998; Paulian, 1971). The results were statisticaly processed. Thus we calculated the feeding rate, the maximum and average number of prey/individual, the weight
