Every third Friday of May is National Endangered Species Day in India, an event showcased across many media outlets even during this dangerous Covid-19 pandemic time. Sadly, very few articles or posts about the day have included mention of freshwater fish, not even the IUCN Red List Critically Endangered hump-backed mahseer, Tor remadevii.
This year's theme is Wildlife Without Borders, which is particularly apt given that mahseer swim freely in rivers and should migrate between states and countries. Tor putitora, the golden mahseer of Himalayan regions is shared by Afghanistan, Pakistan, India, Nepal, Bhutan and possibly parts of China and Myanmar.
In 2019, The Logical Indian prepared a report on changes to the numbers of Red Listed animals in India. It shows that fishes are the most represented group in the Vulnerable category, second most number of species in Endangered and third in Critically Endangered. That amphibians and molluscs are equally heavily represented shows that freshwater and/or marine ecosystems are undoubtedly much more threatened than land-based habitat. Many recent reports have shown the benefits of placing more emphasis on freshwater, and giving equal priority (two links), to freshwater and forests for overall natural system health.
But what does it mean for a fish (or animal or plant for that matter) to be Red Listed and acknowledged as a threatened species? In simple terms, the recognition of threat status allows a conservation action plan to be started. This does not mean that action to protect or rehabilitate that species will happen, but it sets out sensible targets and methods to achieve them, following commonly understood conservation practise.
Before that can happen, we need to be able to recognise each species as distinct from others, and herein lies the problem for many Indian mahseers, and, indeed for mahseers of all countries.
This list (from here, open access paper) of all the currently valid species of mahseer, as recognised by IUCN, shows eight species from India, of which three are Data Deficient. That means not enough is known about them to make an assessment. In all three, correct identification is the main constraint.
Recently we began a programme to 'unlock' the identity of the three unique-looking fish all called Tor tor by locals across the region. There may also be confusion between one of these fish and Tor barakae, possibly the same with another fish and Tor malabaricus, all of which adds another layer of complexity to our task. Following meetings with biologists from Bombay Natural History Society and Tribhuvan University (Nepal), we started to assess fish specimens using an integrated study protocol.
Our Nepal Regional Lead Officer, Sushan Mani Shakya, took collection of one of the so-called Tor tor and passed fin clips to Centre for Molecular Dynamics - Nepal for genetic sequencing, and then carried out a full cyprinid morphological study, a process that involves measuring 38 characteristics. He also took a suite of identification photographs, showing the body in four positions, plus close-ups of the head and each of the fins.
We hope, once pandemic travel restrictions are lifted, to continue this project on all the fish known as Tor tor and to take this integrated study protocol into Myanmar and beyond for all of their mahseer species. In this way, historic confusions over species identity can be resolved and conservation action plans can be started.
If you want to help us continue with this important work, to allow the many unique and valuable species to be correctly identified and be afforded the protection offered to recognised species that are threatened, please consider a donation. You will also help us if you share this article, follow or like us on our social media channels and sign up for our quarterly newsletters.
Don't forget to check out #MahseerMondayQnA on Instagram, where every week an expert on mahseer rivers, mahseer fish or issues affecting those people who interact with mahseer rivers will answer your questions in a video. Send your questions to firstname.lastname@example.org with the subject Mahseer Monday, or tag us on social media with the hashtag.