Characteristics and a comparison of the gut microbiota in two frog species at the beginning and end of hibernation.

Season has been suggested to contribute to variation in the gut microbiota of animals. The complicated relationships between amphibians and their gut microbiota and how they change throughout the year require more research. Short-term and long-term hypothermic fasting of amphibians may affect gut microbiota differently; however, these changes have not been explored.

Effects of fine-scale habitat quality on activity, dormancy, habitat use, and survival after reproduction in Rana dybowskii (Chordata, Amphibia).

Amphibians are facing population declines and extinctions, and protecting and supplementing refuges can help species survive. However, the microhabitat requirements of most species are unknown, and artificial shelters or burrows have not been well tested for amphibians. Some amphibians exhibit complex behaviour during the transition from post-reproductive dormancy to activity.

Changes in the gut microbiota diversity of brown frogs (Rana dybowskii) after an antibiotic bath.

Background: Captive amphibians frequently receive antibiotic baths to control bacterial diseases. The potential collateral effect of these antibiotics on the microbiota of frogs is largely unknown. To date, studies have mainly relied on oral administration to examine the effects of antibiotics on the gut microbiota; in contrast, little is known regarding the effects of bath-applied antibiotics on the gut microbiota.

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

The gut microbiota plays a key role in host health, and disruptions to gut bacterial homeostasis can cause disease. However, the effect of disease on gut microbiota assembly remains unclear and gut microbiota-based predictions of health status is a promising yet poorly established field. Using Illumina high-throughput sequencing technology, we compared the gut microbiota between healthy (HA and HB) and diarrhoeic (DS) groups and analyzed the functional profiles through a phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis.

Environmental and host factors shaping the gut microbiota diversity of brown frog Rana dybowskii.

Symbiotic microbial communities are common in amphibians, and the composition of gut microbial communities varies with factors such as host phylogeny, life stage, ecology, and diet. However, little is known regarding how amphibians acquire their microbiota or how their growth, development, and environmental factors affect the diversity of their microbiotas. We sampled the gut microbiota during different developmental stages of brown frog Rana dybowskii, including tadpoles (T), frogs in metamorphosis (M), frogs just post-metamorphosis and after eating (F), juvenile frogs in summer (Js), adult frogs in summer (As), adult frogs in autumn (Aa), and hibernating frogs (Ah).

Effects of Seasonal Hibernation on the Similarities Between the Skin Microbiota and Gut Microbiota of an Amphibian (Rana dybowskii).

Both the gut and skin microbiotas have important functions for amphibians. The gut microbiota plays an important role in both the health and evolution of the host species, whereas the role of skin microbiota in disease resistance is particularly important for amphibians. Many studies have examined the effects of environmental factors on the skin and gut microbiotas, but no study has yet explored the similarities between the skin and gut microbiotas.

Comparison of the gut microbiota of Rana amurensis and Rana dybowskii under natural winter fasting conditions.

Rana amurensis and R. dybowskii occupy similar habitats. As temperatures decrease with the onset of winter, both species migrate to ponds for hibernation.

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

The gut microbiota of amphibians is affected by exogenous and endogenous factors. We performed a comprehensive analysis using high-throughput sequencing technology and functional predictions and observed general changes in the gut microbiota of frogs in different growth stages, seasons, and growth environments. There were no significant differences in microbial richness and diversity between juvenile and adult wild frogs, between the summer and autumn groups of captive frogs, or between wild and captive frogs.

Modelling the growth of the brown frog ().

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 () 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.

One-wavelength tuning method for a tunable optical filter based on a cascaded polarization interference filter.

A one-wavelength tuning method is proposed to solve the tuning difficulty in a tunable optical filter based on cascaded cells. This method ensures that the optical path difference variation of all of the cells for the tuning is less than one wavelength and lowers the relative tuning accuracy requirement. Simulations show that different cells have different cross talk and loss deterioration when they undergo an error in optical path difference between the O-ray and the E-ray.