Figure: Trying to catch the fish as well as adapt with the targeted fishermen life style.
The Brahmaputra drainage system has been originated from the Manasarovar Lake region, near the Mount Kailash, located on the northern side of the Himalayas in Burang County of Tibet, China. Later it enters into Arunachal Pradesh, India and flows southwest through the Assam Valley as Brahmaputra. Then, it enters into Bangladesh through Kurigram district and divided into two parts near to Dewangonj (Northen part of Jamalpur district): 1) the Brahmaputra (also known as old Brahmaputra) and the Jamuna River. Warm water temperatures, plentiful rainfall, and nutritive silty clay-loam soil make the Brahmaputra drainage system is big resources for icthyofauna in Bangladesh. But many species are now under threat due to unsustainable fishing practices, invasive species, and habitat alteration and loss. In addition, anthropological activities pose thereat of the entire ecosystem in Bangladesh. Therefore, sustainable management of the aquatic resources of the region is urgently needed to conserve the icthyofauna. A prerequisite for this is a careful and accurate assessment of fish species to measure suitable conservation policy for the targeted species.
We provide an updated phylogenetic hypothesis for the genus Microhyla, or oriental tiny frogs. An exhaustive taxonomic sampling for this group is challenging due to the high number of narrow-ranged or point-endemic species across South and Southeast Asia. In the present study, we examine mtDNA and nuDNA markers for 48 of 50 recognized Microhyla species (96%), including 12 nominal species and several undescribed candidate species that have not been examined phylogenetically before our work, thus providing the most comprehensive taxonomic sampling for Microhyla to date.
[Thanks to Nick and his student V. A. Gorin.]
I received small grant from the Ministry of Science and Technology, The People`s Republic of Bangladesh to analyze the cryptic species diversity of freshwater species in Bangladesh.
Stunning variation in terms of landforms and climatic zones supports an enormous variety of habitats, areas of endemism and plethora of biodiversity of Bangladesh. Freshwater fishes supports rural livelihoods here but many species are now under threat due to unsustainable fishing practices, invasive species, and habitat alteration and loss. In addition, anthropological activities pose thereat of the entire ecosystem in Bangladesh. Therefore, sustainable management of the aquatic resources of the region is urgently needed to conserve the icthyofauna. A prerequisite for this is a careful and accurate assessment of fish species to measure suitable conservation policy for the targeted species.
For more than a century, Hylarana tytleri (Theobald, 1868) has been confused with two congeneric species, H. taipehensis and H. erythraea, in Bangladesh and neighboring countries due to phenetic similarities as well as a lack of sufficient molecular and morphometric data. To resolve these problems, we conducted molecular and morphological surveys of Hylarana species throughout Bangladesh and examined H. taipehensis from Taiwan and Vietnam, H. erythraea from Vietnam, Thailand, Myanmar and Malaysia, and H. macrodactyla from China and Vietnam. This paper may be useful as a reference to avoid erroneous species identification of Hylarana species in these regions.
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.
As a continuation of exploring the hitherto overlooked cryptic anuran biodiversity in Bangladesh, I am planning to survey Chittagong Hill tracts area in this summer. I am little excited and hoping to get some marvelous frogs!!
A 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 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