Hynobius amjiensis, also known as the Anji salamander, is an amphibian species currently categorized as endangered due to its limited geographical distribution, primarily in China. To address the critical conservation status of this species, artificial breeding is essential for population expansion. However, progress in artificial breeding efforts has been hindered by the scarcity of research on the reproductive biology of the Anji salamander. In this study, we identified 25 distinct early stages of embryo development. Additionally, we observed that Anji salamander embryos contain a lesser amount of yolk compared to other salamanders or frogs. We further discovered that the Anji salamander employs a highly competitive reproductive strategy, producing a smaller number of high-quality offspring. This strategy aims to generate adaptive individuals through intense intraspecific competition, driven by three factors: extremely confined breeding habitats, a substantial number of eggs, and a reduced yolk content. We introduce the term “mass escape” to describe this strategy, which provides a novel perspective on cannibalization, focusing on the consumption of specific body parts rather than a single-individual activity. This study offers valuable insights into artificial breeding techniques designed to mitigate inherent intraspecific competitive pressure, thereby improving metamorphosis and survival rates. Additionally, it provides a comprehensive table detailing the pre-embryonic developmental stages of the Anji salamander.

The complete mitochondrial genome of the Asian warty newt Paramesotriton chinensis was sequenced. The complete mitogenome of P. chinensis is a circular double-stranded DNA sequence that is 16,361 bp long and was biased toward A + T content at 61.3% (33.0% A, 28.3% T, 23.9% C, and 14.7% G). The complete mitogenome of P. chinensis consists of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 1 ribosomal RNAs (16S rRNA), and 1 putative control region. This study presented the complete mitogenome of P. chinensis and provided essential and important DNA molecular data for further phylogenetic and evolutionary analysis for genus Paramesotriton.