Transformation of Rana tigrina during Progressive Metamorphosis

We determined the kinetics of metamorphosis, apoptosis, and tail regression in Rana tigrina. Acid phosphatase activity (µMole Pi.hr-1.tail-1) in the growing and regressing tail attended six to thirty fold increase respectively. However total activity in the trunk was decreased through progressive growing stages of metamorphosis. Total protein content in the trunk of tadpoles at climax stage (XXI) was decrease (35%) from 2.6mg/ml to 1.7mg/ml. The tail of tadpole tissue has shown a two fold increase in total Ribonucleic Acid (RNA) content from stage III to stage XVIII. But there was again decrease in total RNA content at climax stage (stage XXI). This might be possible due to decreased protein synthetic status. When the experiment was performed in trunk homogenate the amount of total carbohydrate (mg/ml) was slightly increased from 37mg/ml to 38.6mg/ml. this might be due to increase in the activity of α-amylase enzymes in the viscera of developing tadpole when it reached the climax stage.

Changes in the microbial communities of tiger frog (Rana tigrina) meat during refrigerated storage

Microbial activity is the major cause of the spoilage of aquatic meat products during storage. This study investigated the changes of the microbial compositions of the tiger frog (Rana tigrina) meat stored aerobically at 4 ℃ for 12 days using the 16S rRNA amplicon high throughput sequencing (HTS) analysis. The microbial diversity and species richness of the frog meat were abundant at the initial phase of storage but decreased substantially with the prolongation of the storage time. Proteobacteria was the prevalent phylum identified from the frog meat with a relative abundance of 40.29% at day 0 increasing to 96.77% at day 6 and 95.41% at day 12, respectively. At the genus level, Shewanella, Pseudomonas, and Acinetobacter were the three dominant genera in the spoiled samples and contributed to the frog meat spoilage. Their proportions were 41.67%, 28.48%, and 5.94% at day 6, and 29.94%, 23.48%, and 18.44% at day 12, respectively. The present study is conducive to understand the pattern and process of the frog meat spoilage during refrigeration and could be used to develop efficient control measures to mitigate the predominant psychrotrophic spoilers in the aerobically stored frog meat.