Morfološka diferencijacija larvenih stadijuma odabranih vrsta žaba rodova Rana i Bufo na području Srbije
Morphological differentiation of larval stages of selected anuran Rana and Bufo species in Serbia
Abstract:
Brown frogs (R. dalmatina, R. graeca, R. temporaria) and common toad (Bufo bufo) are anuran species that can be syntopic on the territory of Serbia. They can be found in the aquatic habitats only during short breeding season in the early spring. In contrast, their tadpoles are present for a longer period of time in aquatic habitats and are easy to record. Analysis of tadpole morphology is one of the possible ways for species identification, especially when genetic methods are unavailable. Tadpoles at early developmental stages are visually very similar and thus difficult for identification in the field. The main objectives of this study were: to determine external tadpole morphological characters that can serve for taxonomic identification; to determine effectiveness of tadpole shape analyses in taxonomic identification; to develop procedures for their reliable, rapid and economic taxonomic identification. In addition, genetic identification was performed, the usage of traditional and geometric morphometic methods for morphological differentiation of tadpoles at early developmental stages was compared and phylogenetic and phenetic relationships of the analyzed species were examined. Tadpoles at early developmental stages of R. dalmatina, R. temporaria and B. bufo were collected from the field. Taxonomic identification of analyzed species was performed by DNA barcoding, using marker 16S rRNA. Traditional morphometrics was applied and the results suggested that relative head length and head width could be good discriminative characteristics for tadpoles of two Rana species and B. bufo. To distinguish between tadpoles of two analyzed brown frog species, relative tail length could be used. More detailed analyzes of size and shape of successfully laboratory raised R. dalmatina, R. temporaria and B. bufo tadpoles were conducted by comparative (2D landmark-based geometric and traditional) morphometric analyses. Both methodologies produced very similar results considering quantification and description of size and shape variability. Unlike B. bufo tadpoles, tadpoles of two Rana species were with smaller bodies and tails twice as long as the body. When two species of brown frogs were compared, R. dalmatina tadpoles had shorter tails and larger bodies. However, observed subtle shape variation of the distal region of the tail was detected only by geometric morphometrics.
Keywords:
Brown frogs; Common toad; Taxonomic identification; Traditional morphometrics; Geometric morphometrics; Shape; SizeSource:
University of Belgrade, Faculty of Biology, 2020, 1-87Funding / projects:
- Monitoring and Modeling of Rivers and Reservoirs (MORE) - Physical, Chemical, Biological and Morphodynamic Parameters (RS-MESTD-Technological Development (TD or TR)-37009)
- Biosensing Technologies and Global System for Long-Term Research and Integrated Management of Ecosystems (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-43002)