Buicu, Florin - Cristea, Doina (szerk.): Satu Mare. Studii şi comunicări. Seria ştiinţele naturii 9. (2008)
Ştiinţele naturii
Satu Mare - Studii şi Comunicări Seria Ştiinţele Naturii\io\. IX (2008) and frequency of prey taxa and the weight of the taxons varying on its origin. These results were analysed depending on the differences between the sexes, respectively we followed the changes which appear in the food composition throughout the activity period of this population. Results Our study was realised between May and September 2006. We analysed 154 yellow bellied toads, from which 80 were males, 50 females and 24 juveniles. The individuals were captured monthly, starting from May until September, the results being analysed with regards to the period and sex. The feeding activity ratio was high , recording a value of 95,46%. Considering the sexes, there are no differences from this aspect, and with concern to the periods, the majority of individuals that have no stomachal content are present in July and August. With regards to the feeding intensity, this was the highest in the first months of the year, in May, the maximum number of preys being registered here, and even 32 in the case of the females. We can observe the decline of this number towards the beginning of fall, the total maximum number of prey/individual is 20 in June,19 in July, 12 in August and 8 in September. With concern to the average number of prey/individual it was similar to the previous values. The majority of prey taxa have a terrestrial origin, with small unimportant variations with regards to the sexes and the ontogenetic development stage. Depending on the period, in September we can observe the presence of aquatic prey, which is 30% in the case of the females, 21% in the case of the males andl9% in the case of the juveniles. The majority of the stomachal contents was represented by invertebrates. We calculated the weight of these and compared the results depending on the sex, development stage and period. There are certain differences that appear with regards to the weight of prey taxa varying on the sexes. In the case of the males first place is occupied by the Hymenoptera Formicides, followed by the Araneida, Diplopoda, Coleoptera and terrestrial Gastropoda. In the case of the females, the first three taxons are identical with concern to their weight, with the difference that the Gastropodas are replaced by the Diptera Brahicera larvae. The juveniles consumed Afidine and terrestrial Coleopteras in a very large amount. Here the Formicides appear only in the third place and in the fourth place appear the Culicides besides the Araneidas. Certain variations can be seen depending on the period. In the first period the Diptera register the highest value, represented especially by terrestrial Brahicera larvae and Culicides. The Coleopteras, Hymenopteras Formicides and Araneida also have a semnificative weight. In June the situation slightly changes. The Hymenopteras were consumed in a very large amount, thus occuping first place, but here the Afidines, terrestrial Coleoptera and Diptera Brahicera Muscidae also have a very high value. Table no.l. The weight of the prey taxa 20.05 17.06 29.07 19.08 08.09 Gasteropode-(acv)0 0 0 0 9,09 Planorbis 0 0 0 0 1,52 Gasteropode(t)2,34 0 1,93 17,3 7,58 Limax 0 0 0,39 0 0 Pseudoscorpionide 0 0,9 0,39 0 0 Araneide 7,48 6,01 10,8 12,5 18,2 Acarieni 0 0 0 1,92 0 Opilionide 0 0 1,16 0 0 Izopode( t) 1,87 0,9 0,39 3,85 1,52 Gamaride 5,14 0 0 0 0 Diplopode 1,4 5,11 20,1 4,81 4,55 Chilopode 0,47 0 0 0 0 Efemeroptere 0 0,3 0 0 0 Odonate-larve 0 0 0,39 0 0 Odonate 0 0,3 0,39 0 0 Plecoptere 3,27 1,8 0 0 0 Blatoidee 0 0,3 0 0 0 16
