Food of the Banded Newt, Triturus vittatus ophryticus (Berthold, 1846), at Different Sites in Trabzon

Trabzon’un Farklı Yerlerinde Yaşayan Şeritli Semender, Triturus vittatus ophryticus (Berthold, 1846)’un Besini

Abstract

The diet of the banded newt, Triturus vittatus ophryticus, from 3 different sites in northern Turkey was studied based on stomach contents from 180 samples (104 males + 76 females). The banded newt was found to forage on wide variety of prey organisms in the aquatic phase. Benthic invertebrates consistently made the greatest contribution to the diet, both numerically and volumetrically. Nektonic prey also appeared to be of importance in terms of volume but constituted few items. Terrestrial invertebrates contributed very little to the diet. In addition to invertebrates, a few amphibian prey items were found in the stomachs. The number of major prey taxa in the diet was significantly correlated with the seasons (Kruskal-Wallis test, P < 0.01). There were proportionally more Ostracods and Chironomids (larvae and pupae) in the diets of banded newts in spring, whereas Daphnia sp. were largely consumed in late summer and autumn. Differences in the size of newts seem to cause a corresponding significant difference in the selection of large and small prey (rmax = -0.247, P < 0.05). We also found that Triturus vittatus ophryticus consumed similar prey taxa among sites, but that the frequency of the major prey taxa in the diet was significantly different (Tukey's test: P < 0.05) due to ecological conditions.

Özet

Üç fakl› yerde yaflayan fleritli semenderin (Triturus vittatus ophryticus) besinini belirlemek amac› ile 180 (104 erkek + 76 difli) örne¤in midesi incelenmifltir. fieritli semenderin su içinde iken de¤iflik organizmalarla beslendi¤i, bentik omurgas›zlar›n hem say›sal hem de hacimsel olarak en fazla yendi¤i görülmüfltür. Yenilen besinler içerisinde nektonik canl›lar say›sal olarak az olmas›na karfl›n hacimsel olarak önemli yer tutmaktad›rlar. Karasal omurgas›zlar ise çok az yenmifltir. Omurgas›z hayvanlara ilaveten birkaç kuyruksuz kurba¤an›n da besin olarak al›nd›¤› tespit edilmifltir. Fazla yenen canl› gruplar›n›n say›s›n›n mevsimsel olarak önemli oranda de¤ifliklik gösterdi¤i görülmüfltür (Kruskal-Wallis test, P < 0,01). Osracod ve Chironomidler (larva ve pup) daha çok ilkbaharda yenirken, su presi (Daphnia sp.)’n›n yaz ve sonbaharda yendi¤i görülmüfltür. Di¤er taraftan semenderlerin büyüklü¤ü ile al›nan besinin büyüklü¤ü aras›nda önemli iliflki bulunmufltur (rmax = -0,247, P < 0,05). Ayr›ca, farkl› üç yerde yaflayan fleritli semenderin benzer canl›lar yedi¤i fakat bu canl›lar›n yenme s›kl›¤›n›n önemli oranda (Tukey test: P < 0,05) farkl›l›k gösterdi¤i görülmüfltür.