Rare glimpse of hill river fish diversity in Sylhet’s Sada Pathor, Jaflong

During my recent survey in the foothill areas of the Tura Hills near Meghalaya, India, I visited the picturesque lowlands of Companiganj, Sylhet. This area is known for its stunning riverbanks and crystal-clear waters cascading over boulders, making it a hub for ecotourism. Alongside a diverse team including engineers, architects, designers, environmentalists, university educators, and law enforcers, I explored the potential for sustainable tourism here.

Ministry of Water Resources and the district administration at Sylhet organised a whirlwind tour of the area as we had to cover four different touristic sites in less than 36 hours during 25-26 September 2025. I could cover only three sites as I had to do groundcover looking for the biodiversity.

In addition to supporting the team, I conducted my own survey of the local biodiversity, focusing on aquatic life. While walking along the Dholai River, I encountered a few fishers. Though their catch was sparse, one fisher had managed to net two fish from the carp family. Later, in the Dawki River in Jaflong, I met two other fishers with a more substantial catch. At dusk, they kindly allowed me to photograph the fish before returning them to their baskets.

ish Species Encountered:

These fish were familiar to me from my postgraduate research in the 1960s. While I had forgotten some zoological names, the Bengali names remained memorable. After returning to Dhaka, I shared the photos on social media and received several identifications. I reached out to Dr. Md. Sagir Ahmed, a former student and fisheries expert, for clarity. He quickly confirmed the identities of most fish species.
Fish Species Identified:

• Family: Cyprinidae

Amblypharyngodon mola (Mola Carplet, Pale Carplet) – Least Concern
Pethia conchonius (Rosy Barb) – Least Concern
Systomus sarana (Olive Barb) – Near Threatened
Opsarius barna (Barna Baril) – Endangered
Opsarius bendelisis (Hamilton’s Barila) – Endangered
Salmophasia bacaila (Large Razorbelly Minnow) Least Concern

• Family: Bagridae

Batasio tengana (Dwarf Catfish Dwarf Catfish) – Endangered
Mystus cavasius (Gangetic Mystus) – Near Threatened
Mystus tengara (Tengra Catfish) – Least Concern

• Family: Ambassidae

Parambassis baculis (Himalayan Glassy Perchlet)- Near Threatened

• Family: Characidae

Chela cachius (Freshwater Hatchetfish) – Vulnerable
• Family: Botiidae

Botia rostrata (Bengal Loach) – Data Deficient

• Family: Giuriidae

Another batch of mixed catch of riverine fishes at Jaflong on the bank of Dawki River. Photo: Collected
• Family: Mastacembelidae

Mastacembelus armatus (Zig-zag Eel) – Endangered
• Family: Clupeidae

Gudusia chapra (Indian River Shad) – Vulnerable
• Family: Belonidae

Xenentodon cancila (Freshwater Garfish) – Least Concern
• Family: Channidae

Channa gachua (Dwarf Snakehead) – Least Concern

Observations and Findings:

Typically, local fish species are researched by visiting the fish market. However, due to time constraints, I decided to engage directly with local fishers and record the species from their catches. In the short 36 hours spent in Sylhet, I identified 17 species across 11 families. The Cyprinidae family was most dominant, with Bagridae contributing two species. A more extensive survey could yield a clearer picture of the biodiversity in these rivers.

Threatened Fish Species:

The IUCN Red List categorizes species based on their risk of extinction, ranging from Critically Endangered (CR) to Vulnerable (VU). Four species in this survey were classified as Endangered, and two as Vulnerable. Four other species were Near Threatened, and five were Least Concern. One species, identified as Data Deficient, and another lacked sufficient information for classification.

The fish fauna of the Dholai and Dawki rivers is a testament to the rich biodiversity of the region. However, many of these species are threatened and require strong conservation efforts to prevent their decline. Overfishing and habitat disturbance must be addressed to safeguard these fragile populations. Ecotourism planning should ensure the protection of these hillstream fishes and their habitats.

Special thanks to Prof. Sagir for his timely identification, as well as to my field companions, Shome and Abdul Karim Kim, for their valuable assistance. Shome helped me identifying dragonfly.

Endnote: In addition to the fishes, our brief survey of the riverbank areas at Jaflong led to the spotting of two species of common amphibians:

Skipper Frog (Euphlyctis cyanophlyctis)
Bullfrog (Hoplobatrachus tigerinus)

We also observed one species of prawn:

Kuncho River Prawn (Macrobrachium lamarrei) possibly this species!