Reproductive isolating mechanism of coastal bull frog

Cross section of seminiferous tubules in the testes visually show how the hybrid of anurans are distinct from each other, particularly from the control one. Of course, morphologically you can identify the hybrids from the control one, but always this kind of identification may not satisfy you. However, the internal cell rupture or state of seminiferous tubules in meiosis stage (seminiferous tubules filled with compact bundle of normal spermatozoa/seminiferous tubules with pycnotic nuclei) clearly give you the evidence how a hybrid really distinct from the control one. This is a clear-cut separation between and/or among hybrids and controls.
See details in Hasan et al., 2017: Reproductive isolating mechanisms in the Bangladesh Coastal Bullfrog Hoplobatrachus litoralis and its congeneric species revealed by crossing experiments and examination on spermatogenesis of the hybrids. Asian Herpetological Research, 8:27–38.

My discovery of new frog (H. litoralis) is new to science after 150 years later

H. litoralis 2A new cryptic species of the genus Hoplobatrachus from Cox’s Bazar district of Bangladesh is described and compared with its relevant congeners both in morphology and mitochondrial gene sequences. Based on mtDNA data, this new species was proved to genetically divergent from H. tigerinus at 3.2% for the 16S rRNA gene and 14.2% for the Cytb gene. The known distribution range of the new species is restricted to southeastern corner of Bangladesh and it seems to endemic in this coastal belt. It is new to the genus Hoplobatrachus after 150 years later.

Two New Frog Species

Two New Frogs_BdTwo new frog species were recently described from Bangladesh. The first (M. mymensinghensis) and the second new species (M. mukhlesuri) seems to have separated from their closest relatives more than 3.4 Million and 10.5 Million years ago, respectively. Their ancestors supposed to have evolved somewhere in East and Southeast Asia. Please find the preview of the paper here