Siruvani sampling, day one


December 23. Summary: went to the tribal village to pick up two forest officials, then proceeded to the checkpoint and hiked in 2.5 km to site 1 where we collected with cast nets and trap nets and processed fish at the site. Site 2 was not too far upstream, and after collecting there and returning to Patiyar, we deployed a larger-mesh gill net in the reservoir below a small falls within walking distance of the guest house. Saw a Sambar Deer on walk back to Patiyar.

Today we sampled on a tributary down the road from Siruvani Dam, though it was not the tailwater of the dam itself. The two spots were what I would call a very tiny brook—that is, about 5-10 ft3/second with shallow runs and braids over boulders. Water temperature was right around 20°C. We collected with cast nets mostly, though a trap net was used below a bit of faster water in the first spot and a gill net was deployed at the second. I counted six species collected and there were also a handful of barbs occupying a bit of slack water, but they didn’t make it into the species count.


Mudugar settlement in core area of Siruvani Reserve Forest, Kerala.

We first took the Jeep to a tribal village (Mudugar tribe) to pick up two Department of Forestry representatives/observers. “Tribals” (as they are called here) are ethnically, culturally, and socially isolated from the rest of India. They are allowed to keep to themselves, though some are moving out of the forests and into the towns and adopting something close to a 20th century life. With so many in India living on very little income, the tribal who self-transplants into mainstream India does not find himself as economic underclass, though I imagine that some prejudice persists. On the other hand I imagine there is also less economic incentive to move out of the tribal village as well, though the trappings of modern life—cell phones, motor bikes, slick Western clothing—is continually in their faces, not only from television but also from daily interaction with non-tribal India.

In the case of the Mudugar people, their home village is nicely appointed with solidly built and permanent concrete structures—much more posh than most living below the poverty line in modern Indian cities. This particular tribe had occupied an area of the forest that is presently under water due to the construction of Siruvani Dam. Establishing an acceptable new space for the tribals’ relocation was part of the government-directed mitigation. They are growing coconut palms and raising chickens within the core area of this ecological reserve—such activities are not permitted by anyone other than tribals, and they are also part-time stewards of the Siruvani reserve—though this is a much less significant role compared with the local control of the Yanayacu Reserve that I visited in Peru with Seth and Karen (see the Peru part of my blog).


Ana virithi, or “elephant run away.” This inconspicuous and dangerous understory plant has leaves with such a strong irritant that even elephants are affected. Yes, if your name is Ana (or Anna), your name means “elephant” in the Tamil language.

Now with six humans in a small Jeep (actually a Mahindra) along with tons of equipment, we parked at the third checkpoint from which we had a 2.5 km hike to the first site with a large volume of equipment. Mani and his students made sure that I had only a light load while they (especially the grad students a.k.a. pack animals) bore significantly greater burdens.

I learned a few things on the hiking route. Ana virithi is an understory plant with a very strong irritant in its leaves and flowers. Its name comes from “ana” which is elephant and “virithi” which is “run away” (another name that we used more commonly is ana marthi, though nobody could tell me what “marthi” means). If even the thick-skinned elephant is subject to irritation by this inconspicuous bit of landscaping I was very careful about not touching it. The infamous forest leeches of Asian forests are there. They find their way onto your shoes (or between your toes if you’re not wearing shoes), but they are black and easy to spot and remove before they start to feed. If they do manage to escape your notice they take their meal and fall off, but the wound left behind continues to bleed for a bit, presumably due to the anticoagulant activity of the leech’s saliva (hirudin, I think, is the anesthetic and maybe it is also the anticoagulant). I learned that elephants, in addition to being noisy in the way they move through the forest, are also smelly. Magesh picked up the scent of nearby elephant and alerted me to be very cautious.


A small-mesh drag net is placed below a fast run, then the rocks on the bottom are jostled manually to dislodge fishes that like to anchor and feed in these fast strecthes.

The sampling started with a quick survey/assessment of the fishes that are evident and their locations within the habitat: runs, riffles, etc. To me the most striking fish there was the Indian Trout, Barilius getensis, which from an angler’s eye view looked exactly like rainbow trout (though too small to make me wish I’d brought my fishing gear). Then a comprehensive collection was done with the net-based methods I mentioned earlier, and I’d say at least fifty fish were collected at each site. Dr. Mani then meticulously photographed each species using a digital SLR. A live fish was placed in a water-filled mini-aquarium (find a better word here), which was set atop a second tripod—yeah, we hauled in two tripods in addition to everything else. But I’m sure that his photos are the best around. He took several dozen shots of each fish from different angles, and we spent a lot of time coaxing the fish into the ideal position, preferably with fins maximally flared.


Pectoral fin, pelvic fin, and a gram of flesh go into an Epi tube for DNA barcoding, and the rest of the fish is tagged and preserved.

Arun and Magesh were then put to work collecting samples for DNA barcoding (they are using the same COI partial sequence that we use in our BIO204 labs). A pectoral fin, a pelvic fin, and about a 1 cm3 sample of tissue was cut from the top half (epaxial, for you fish people) of the muscle. The rest of the fish was tagged and dropped into a formalin solution. On smaller fish that were large enough to fit into the 2 mL Epindorf tube, the whole fish was put in. This activity pressed on into the early afternoon, and after lunching they collected physical data on each collection point: depth, width, flow velocity, pH, dissolved oxygen. We then moved to a second site, perhaps 0.5-1 km downstream from the first site.

Walking back to Patiyar in the dark, we scanned the forest for eye-shine--reflection from our flashlights. I saw a Sambar deer with yellow eyes. [This image by Manimekalan is actually a young Indian Gaur from a different day.]

Walking back to Patiyar in the dark, we scanned the forest for eye-shine–reflection from our flashlights. I saw a Sambar deer with yellow eyes. [This image by Manimekalan is actually a young Indian Gaur from a different day.]

Pressed for time—not a good idea to be this far from the road after dark given the presence of leopards and tigers and elephants and king cobras—we collected, took DNA samples, stream data and returned back to the car.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: