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Species

· South Asia (Indus and Ganges river systems) · 2 min read

Indus River Dolphin vs Ganges River Dolphin: What's the Difference?

In brief

The Indus River dolphin (Platanista minor) and Ganges River dolphin (Platanista gangetica) were recognised as separate species in 2021 based on distinct skull shape, genetic differences and long isolation; the Indus lives in Pakistan and the Ganges across India, Bangladesh and Nepal, and both are blind and Endangered.

Key Takeaways

  • The Indus (Platanista minor) and Ganges (Platanista gangetica) river dolphins were recognised as separate species in 2021.
  • The split was based on distinct skull shapes, fixed genetic differences and an estimated half-million years of isolation.
  • The Indus dolphin (bhulan) lives in Pakistan's Indus; the Ganges dolphin (susu) ranges across India, Bangladesh and Nepal.
  • Both species are functionally blind, hunt by echolocation, and are listed as Endangered by the IUCN.
  • Both face the same primary threat: dams and irrigation barrages that fragment their river habitat.

The Indus and Ganges river dolphins are so alike that scientists treated them as a single species for decades. Both are blind, both have long tooth-lined beaks, and both haunt the muddy rivers of South Asia. Yet in 2021 researchers concluded they are in fact two distinct species. Here is what separates them. For a deeper profile of the Indus animal, see our Indus River dolphin species guide.

They were split into two species in 2021

A taxonomic revision published in 2021 examined skulls, body measurements and DNA and found the two populations had been reproductively and geographically isolated for roughly half a million years. The Indus dolphin was elevated to its own species, Platanista minor, separate from the Ganges dolphin, Platanista gangetica.

The evidence behind the split

  • Skull shape: the frontal bones behind the nasal openings differ consistently between the two, regardless of an animal's age, sex or size.
  • Genetics: the two river systems share no mitochondrial DNA haplotypes, with fixed genetic differences pointing to long-term separation.
  • Other traits: the species also differ in tooth counts, coloration and growth patterns.

Different rivers, different names

The Indus River dolphin, or bhulan, lives in Pakistan's Indus system. The Ganges River dolphin, called susu or shushuk, ranges across the Ganges-Brahmaputra-Meghna system in India, Bangladesh and Nepal. Their ranges do not overlap.

What they share

Both are functionally blind, lacking a crystalline eye lens, and both navigate and hunt by echolocation. Both are listed as Endangered on the IUCN Red List, and both face the same core threat: dams and water diversion that fragment their rivers.

Quick comparison

  • Indus River dolphinPlatanista minor; bhulan; Indus River, Pakistan; Endangered.
  • Ganges River dolphinPlatanista gangetica; susu/shushuk; Ganges-Brahmaputra-Meghna system; Endangered.

Of the two, the Indus dolphin lives within a country where our partner-funded teams operate. If you'd like to help, you can back river-habitat protection that supports the bhulan's last strongholds.

Frequently Asked Questions

Are Indus and Ganges river dolphins the same species?
No. They were long treated as one species but were recognised as two separate species in a 2021 taxonomic revision, based on skull, genetic and morphological differences.
How do you tell an Indus River dolphin from a Ganges River dolphin?
By range and biology rather than by sight in the field: the Indus dolphin lives in Pakistan's Indus, the Ganges dolphin in the Ganges-Brahmaputra-Meghna system. Scientifically they differ in frontal-bone skull shape, tooth counts and DNA.
Are both river dolphins endangered?
Yes. Both the Indus and Ganges river dolphins are listed as Endangered on the IUCN Red List, mainly because of dams and water diversion that fragment their habitat.
W

WARN Research & Conservation Team

World Animal Rescue Network

Published 2 min read · 354 words
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