Modelling the growth of the brown frog (Rana dybowskii)

Abstract

Well-controlled development leads to uniform body size and a better growth rate; therefore, the ability to determine the growth rate of frogs and their period of sexual maturity is essential for producing healthy, high-quality descendant frogs. To establish a working model that can best predict the growth performance of frogs, the present study examined the growth of one-year-old and two-year-old brown frogs (Rana dybowskii) from metamorphosis to hibernation (18 weeks) and out-hibernation to hibernation (20 weeks) under the same environmental conditions. Brown frog growth was studied and mathematically modelled using various nonlinear, linear, and polynomial functions. The model input values were statistically evaluated using parameters such as the Akaike’s information criterion. The body weight/size ratio (Kwl) and Fulton’s condition factor (K) were used to compare the weight and size of groups of frogs during the growth period. The results showed that the third- and fourth-order polynomial models provided the most consistent predictions of body weight for age 1 and age 2 brown frogs, respectively. Both the Gompertz and third-order polynomial models yielded similarly adequate results for the body size of age 1 brown frogs, while the Janoschek model produced a similarly adequate result for the body size of age 2 brown frogs. The Brody and Janoschek models yielded the highest and lowest estimates of asymptotic weight, respectively, for the body weights of all frogs. The Kwl value of all frogs increased from 0.40 to 3.18. The K value of age 1 frogs decreased from 23.81 to 9.45 in the first four weeks. The K value of age 2 frogs remained close to 10. Graphically, a sigmoidal trend was observed for body weight and body size with increasing age. The results of this study will be useful not only for amphibian research but also for frog farming management strategies and decisions.

Effects of Captivity and Season on the Gut Microbiota of the Brown Frog (Rana dybowskii)

“…Furthermore, the food demands of the two groups were different. Soon after hibernation, the frogs actively consumed food, entered the fast-growing stage and required more nutrients than they did during the growth stage (Tong et al, 2018). The frogs consumed food less actively in September than in the summer.…”

“…Several studies have revealed differences in the skin microbiota between captive and wild amphibians (Becker et al, 2014; Loudon et al, 2014; Bataille et al, 2016; Xiang et al, 2018). R. dybowskii is a completely terrestrial species with a long breeding cycle, typically 2–3 years, and its rearing methods are very different from those of other frogs of economic importance, such as the bullfrog (Tong et al, 2018). Studying the gut microbiota of R. dybowskii , which is a completely terrestrial species that has been domesticated at a high density for 2 years, gives us a rare opportunity to understand the gut flora under such conditions.…”

Comparison of Gut Microbiota Diversity and Predicted Functions Between Healthy and Diseased Captive Rana dybowskii

“…Rana dybowskii (brown frog) is an important aquaculture species with both medicinal and nutritional value ( Tong et al, 2018 ). The conditions in which amphibians live in captivity are highly different from those in the wild, and a higher mortality of frogs occurs at higher densities in culture environments ( Xiang et al, 2018 ; Tong et al, 2019 ).…”

Comparative analysis of cutaneous bacterial communities of farmed Rana dybowskii after gentamycin bath

“…Oviductus ranae (OR) is a traditional and highly safe animal-based Chinese medicine that has been listed in the Chinese Pharmacopoeia since 1985 (Zhang et al, 2017). To protect and rationally use R. dybowskii, extensive studies of its ecology, artificial domestication and utilization have been performed (Tong et al, 2018). Since development of the R. dybowskii breeding industry more than 30 years ago, research has focused on improving the artificial breeding process.…”