Discovering a New Species in Assam

During a biodiversity survey in early July 2025, researchers from ICAR‑CIFRI and Manipur University unveiled a new fish species in the Brahmaputra River near Maijan, Dibrugarh, Assam. Named Pethia dibrugarhensis, this cyprinid fish adds to India’s rich freshwater fauna. 0

Physical Characteristics and Distinct Features

Pethia dibrugarhensis stands out for several unique traits: it exhibits an incomplete lateral line, lacks barbels and humeral spots, and bears a distinct black blotch near the tail extending vertically. It also has 10 scales around its caudal peduncle, with four rows each between the dorsal-fin to lateral line and lateral line to pelvic-fin—marking significant morphological deviations from related species. 1

Survey and Taxonomy: Who Did the Work?

The discovery was led by Basanta Kumar Das and his team—including Niti Sharma, Simanku Borah (ICAR‑CIFRI), W. Vishwanath, and M. Dishma (Manipur University). Their findings were published in National Academy Science Letters, highlighting both scientific and conservation importance. 2

Habitat and Ecological Context

This cyprinid inhabits moderately fast-flowing sections of the Brahmaputra, with riverbeds of mixed mud, sand, and stones. It shares the habitat with other endemic species within Assam’s freshwater ecosystems. 3

Significance for Conservation

Anchoring this species discovery is the message for urgent river conservation. Researchers emphasized that cataloguing such endemic biodiversity is crucial to preserve fragile aquatic ecosystems facing threats like pollution and habitat loss. 4

Timeline of Discovery

• Early July 2025: Fish survey conducted near Maijan, Dibrugarh.
• July 7, 2025: Pethia dibrugarhensis formally named and described in academic journal.
• Ongoing: Calls for habitat protection and expanded surveys intensified post-discovery.

Trivia & Taxonomic Insights

• The genus Pethia belongs to the family Cyprinidae, which includes carps and minnows—the most species-rich freshwater fish family.
• Dibrugarh has previously been type locality for species like Channa aurantimaculata, the orange-spotted snakehead.
• An incomplete lateral line—a sensory organ—is rare and marks a noteworthy taxonomic distinction.

The discovery of Pethia dibrugarhensis highlights how much remains hidden beneath India’s river waters—encouraging future exploration and conservation action to protect these freshwater gems.

Source: News 18