Two numbers sit over Rajaji's fishes: 42 and 49. One comes from an uncited sentence on the reserve's official website, the other from a Zoological Survey of India chapter published in March 1995. They are not two readings of the same measurement, and neither of them is a count made this year. This page sets out both figures, where each comes from, why the older one is the better documented of the two, and why this page still declines to name a current fish total for the park.
Sources checked on 2 November 2026: the Zoological Survey of India's own copy of Fauna of Conservation Area 5: Rajaji National Park (March 1995, 323 pp.), read as a scanned PDF; and the reserve's About page together with its archived copy of 23 February 2024, where the 42-species sentence stands unchanged.
The ZSI chapter: 49 species
The fish chapter is by Akhlaq Husain and Raj Tilak of the Northern Regional Station, Zoological Survey of India, Dehradun, and runs from page 115 to page 193 of the 1995 volume — the longest single group account in the book. It reports 49 species of fishes belonging to 30 genera, 12 families and 4 orders. Two of those species carry extra weight in the chapter's own framing:
- Barilius dimorphicus — described as new to science by Tilak and Husain in 1990, from material collected in the park. The chapter notes that it grows to quite a good size and is very attractive to look at.
- Nemacheilus doonensis — a small loach recorded as new to the park.
The chapter is also careful about what it rejects. Earlier lists from the extended area are queried in it: several records are called doubtful, some are attributed to misidentifications, and one estuarine species reported from the area is said not to be expected there at all. That scepticism is part of why the chapter's 49 is worth holding on its own terms rather than averaging it against anything.
The localities surveyed are given district by district. In the Dehradun district they include the Song river at Kansrao and near the Kansrao railway station and bridge, the Song river near Satyanarain and at Pritinagar and Gaurighat, the Ganga river near its union with the Song at Gaurighat near Satyanarain, the Suswa river at several points including near Clement Town and Phandowala, and the Motichur rao near the Motichur Forest Rest House. Pauri-Garhwal localities include streams around Chilla and the Ganga canal; Hardwar district localities include the Mohand, Chilkana, Gaj, Bhinj and Ranipur raos. The chapter describes its area as covering the Dehradun, Pauri-Garhwal and Hardwar districts — the district arrangement of the period.
The website: around 42 species
The reserve's own About page carries a single sentence on fishes, inside its overview of the tiger reserve's biodiversity:
"Around 42 species of fishes breed in the acquatic habitat supported by rivers, streams passing through the Tiger Reserve." [sic]
The spelling of "acquatic" is the page's own and is reproduced as printed. What matters more is the sentence's structure: it is uncited. No report, no author, no date and no list is attached to it, and the official site publishes no species list of any kind for its waters. The wording is the same in the archived copy of the About page from 23 February 2024, so it is not a fresh edit, and it was still uncorrected when checked on 2 November 2026. Note also that the sentence speaks of the Tiger Reserve, while the ZSI chapter speaks of the national park as then defined — two different legal objects with different extents, quoted by two different institutions thirty years apart.
42 against 49, held open
Read side by side, the two figures are a discrepancy, not a competition. The 49 comes from a March 1995 official inventory: named authors, identified specimens, published localities, a chapter that can be opened and checked page by page. The 42 comes from a website sentence with nothing behind it that a reader could follow. That difference in evidentiary weight is real, and it is the reason this page leads with the ZSI chapter. But the difference is not a licence to declare 49 correct either: the 1995 volume is a dated record resting on collections made before publication, it predates the final national park notification of 14 September 2013 and uses the then-park boundary, and a list of what was caught and identified in the 1970s, 1980s and 1990s is not a census of what swims in the river now.
So both numbers are printed here with their sources attached, and neither is presented as the current fish count for Rajaji. No present-day total was published or located as of 2 November 2026. When one is, it should be read the way these two are: with its method, its date, its boundary and its author attached.
What this page will not claim
Three abstentions. There is no current fish total for Rajaji here, and no claim that 42 is settled or that 49 is. There are no rules, permits or prohibitions of any kind stated on this page: none of the sources used here addresses them, and none was verified from a primary source as of 2 November 2026. And there is no ecological elaboration — no statement about which species breed where, how populations are doing, or what the rivers support today, because none of that was read out of the sources.
Where to read next
For the water the fishes live in, the rivers and waterholes guide covers the Ganga, its tributaries and the dry-season concentration points. For the river species a visitor might actually see, the wildlife guide's reptiles and aquatic life section sets out the gharial and mugger crocodiles that share those stretches. Asan Conservation Reserve publishes a fish figure of 49 as well — but that is Asan's own richness figure, from a different wetland in the Yamuna basin, not a second witness for Rajaji. For the wider fauna the 1995 volume inventories, the animals list. The two companion chapters of the same book are the butterfly record and the dragonfly and damselfly record. Sources checked 2 November 2026.
Rajaji's fish record: questions answered
How many fish species does Rajaji have?
Two figures are on the record and this page settles neither. The Zoological Survey of India's March 1995 fish chapter gives 49 species belonging to 30 genera, 12 families and 4 orders; the official About page, as archived on 23 February 2024, states "Around 42 species of fishes breed in the acquatic habitat supported by rivers, streams passing through the Tiger Reserve." [sic] — an uncited sentence on a site that publishes no species list: https://web.archive.org/web/20240223205940/https://rajajitigerreserve.uk.gov.in/About.aspx
Who wrote the ZSI fish chapter and what does it contain?
Akhlaq Husain and Raj Tilak of the Northern Regional Station, Zoological Survey of India, Dehradun, in a chapter running from page 115 to page 193 of the March 1995 volume. It records 49 species in 30 genera, 12 families and 4 orders, and it includes Barilius dimorphicus, described as new to science by Tilak and Husain in 1990, and Nemacheilus doonensis, recorded as new to the park. Volume: https://zsi.gov.in/public/PDFVolumes/cas/005/index.pdf
Where were the fish collected?
The chapter's localities include the Song river at Kansrao and near Satyanarain, the Ganga near its union with the Song at Gaurighat near Satyanarain, the Suswa river at several points including near Clement Town and Phandowala, and the Motichur rao near the Motichur Forest Rest House. The surveyed area is described in the chapter as covering the Dehradun, Pauri-Garhwal and Hardwar districts.
Which figure is correct, 42 or 49?
Neither is presented here as settled, because they are answers to different questions from different dates. The 49 comes from a March 1995 official inventory built on identified specimens; the 42 is an uncited sentence on an official website with no list behind it. The 1995 volume also predates the final national park notification of 14 September 2013 and uses the then-park boundary, so even its 49 is a dated figure for an area as it was defined at the time.
Does the 42 sentence and the 49 chapter describe the same area?
Not on their face. The About page sentence speaks of the Tiger Reserve, while the 1995 chapter speaks of the national park as it was then defined — two different legal objects with different extents, quoted by two different institutions about thirty years apart. That difference does not resolve the numbers, but it does mean they are not two counts of the same ground: https://zsi.gov.in/public/PDFVolumes/cas/005/index.pdf