posted on 2019-06-24, 12:48authored byMarija Ilić, Vida Jojić, Gorana Stamenković, Vanja Marković, Vladica Simić, Momir Paunović, Jelka Crnobrnja-Isailović
We conducted a comparative (2D landmark-based
geometric and traditional) morphometric analysis on tadpoles at early
developmental stages.
Two species of brown frog (Rana dalmatina and R. temporaria) and the common
toad (Bufo bufo) were involved, all
raised in the laboratory from fertilized eggs collected in their natural
habitat. Taxonomic identification was confirmed by the DNA barcoding method
with the 16S rRNA sequence asthe gene marker. Interested to compare
the methodologies for
quantification and description of morphological differences among
tadpoles of mentioned species, we aimed to: 1) calculate interspecies genetic
distances as the most relevant measurement for species differentiation, 2)
determine and describe size and shape variation, 3) identify relationships
among the analyzed species at the morphological level and 4) assess their
classification accuracy. Within the framework
of the specified aims, both methodologies produced very similar results, i.e.,
the smallest divergence was between R. dalmatina and R. temporaria,while the most discriminative were B. bufo and R. temporaria. However, we observed subtle shape variation of the distal region of the tail that was detected
only by the geometric morphometrics. Our findings
support the following. Geometric
morphometric method captures more subtle shape differences that were
unable to be recovered from linear measurements. It performs slightly better in
classification rate. Although it was not quantified, it stands to reason that
there is no difference in time investment between the two approaches. Geometric
morphometrics provides more information that can be leveraged to answer further
questions and it has a clear advantage in visualizing.