Abstract
The size of amphibian erythrocytes is positively correlated to their DNA content. Therefore, planimetry of erythrocytes has long been used to determine ploidy levels in amphibians. In Rana esculenta. a hybrid originating from Rana ridibunda x Rana lessonae natural crosses, planimetric determination of erythrocyte size is used to distinguish diploid and triploid specimen. In the present study we performed planimetric analyses on the hybrid Rana grafi, comprising a second hybridogenetic system with its parental species Rana ridibunda and Rana perezi in southern parts of France. We found size differences of diploid and triploid erythrocytes to range between 26 and 33% in studies on adult R. esculenta and calculated a mean difference of 30%. Our results strongly support a significant influence of the factors snout-vent-length (SVL), geographic location, organic matter of substratum, and relative amount of oxygen on the erythrocyte size of these hybrids. Discriminant analyses proved a probability of approximately 30% to disaffiliate individuals in our data set and indicated that ploidy determinations on individuals will be most unprobable, if the SVL of individuals strongly staggers and the habitats differ in their environmental characteristics. Due to the found dependencies of the erythrocyte size to several factors we consider planimetric analysis for reasons of ploidy determination as unprobable and thus we favour more sophisticated techniques such as DNA-flowcytometry or karyotype analyses.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
