Morphometrics of Xenopus laevis Kept as Laboratory Animals

SIMPLE SUMMARY: Body conditions can be indicators of nutritional status and health in animals. Thus, it is important to monitor body conditions. In laboratory animals, this is of special interest during experiments, on the one hand, to evaluate the stress the animal is exposed to, and on the other hand, the recordings of these parameters are important in order to provide the animals with appropriate husbandry conditions in their lives and metabolic needs. For African clawed frogs, Xenopus laevis, as amphibians, the use of body condition scores or indices has not been implemented as yet. In the present study, adult male and female Xenopus laevis were weighed and several measurements were taken from standardized photographs to establish tools for body condition evaluations in this species. Such morphometric data can serve as reference data for body condition evaluations. ABSTRACT: Morphometric data that provide information on body conditions can be used to monitor the health and well-being of animals. In laboratory animals, they can help to evaluate the stress due to experiments or treatments, following the 3R principles. The aim of the present study was to obtain morphometric data of male and female African clawed frogs, Xenopus laevis, as the bases for body condition evaluations. Adult frogs (n = 198) were weighed and standardized photographs were taken. The photographs were used to determine several measurements (length, cranial width, caudal width, thigh width). In addition, a triangle was drawn to outline each frog’s simplified body form, and the triangle surface was calculated. In conclusion, the triangle surface drawn on the dorsal plane of each frog correlated with the body weight of the females. There were significant differences between the body weights and sizes of male and female frogs, with males being smaller (p < 0.001). Based on the morphometric data, females could be assigned to five groups in which an assessment of the animal’s well-being is feasible.