Heiko Bleher's India Expeditions

Meruvambayi River

By Amar Salvi

Estimated read time: 4-5 minutes

I still remember that warm afternoon in Italy in 2015 when I first met Heiko Bleher, his wife Natasha Khardina, and their little daughter Amanda. For me, it was a dream come true. I was with my hero - someone I had admired for years - and here I was, listening to him rattle off one fascinating anecdote after another about his countless expeditions around the world. That day, he spoke at length about his trips to India. Before I left, Heiko pressed into my arms three enormous volumes - his life's work: Bleher's Discus Volume 1, Discus Volume 2, and Bleher's Biotopes. Carrying those heavy books back to India felt like holding a piece of aquatic history itself. Back home, I could barely wait. I opened Bleher's Biotopes, and naturally, my eyes went straight to the section on India - a country Heiko had explored with characteristic intensity. What unfolded across those pages was more than a travelogue; it was a detailed record of rivers, landscapes, and lives connected by water.

Into the Western Ghats

Heiko's Indian journey began in the Western Ghats, one of the world's richest biodiversity regions. Starting from Madikeri, he drove through the Brahmagiri Wildlife Sanctuary, a stretch of dense forest alive with promise. The 60-kilometre track was rough, but it was here that he found what he was looking for - not large animals, but life in miniature. In a stagnant mountain creek, he discovered a catfish, Pterocryptis cochinchinensis, and soon after, a brilliantly coloured Barilius unlike any he had seen before. The fish shimmered in a spectrum of colours, and Heiko wondered if it might be new to science.

Rivers of Abundance

From there, he continued south through Siddapura toward Iritty, where he met his friend Pushpan. Together they reached the Meruvambayi River, a tributary of the Valapattanam. Its shallow margins were lined with aquatic plants - Limnophila indica, Marsilea quadrifolia, Myriophyllum dicoccum, Rotala indica, and Nymphaea species.

The river held a remarkable community:

• Dawkinsia filamentosa

• Parambassis dayi

• Pseudosphromenus cupanus

• Ompok malabaricus

• Pristolepis marginata

• Surface-dwellers like Xenentodon cancila Heiko marvelled that so many fish could survive in water barely ankle-deep and without flow.

"Nature," he wrote, "is unpredictable and often misunderstood by man."

Kerala's Hidden Streams

He moved next to the Kadalundi River in Kozhikode. Collecting at night, Heiko recorded Sahyadria sp., Hypselobarbus jerdoni, Awaous grammepomus, Batasio travancoria, and Pseudetroplus maculatus. Even the familiar Etroplus maculatus appeared in colours and forms unseen in the aquarium trade. At the Kuthira River, beneath an eighteenth-century stone bridge, he found Aplocheilus lineatus, A. kirschmerii, Devario malabaricus, and thriving stands of Cryptocoryne retrospiralis. Locals gathered to watch as he worked - fifty people, by his count - proof that curiosity travels both ways

The Creek at Connolly's Plot

At the Chaliyar River, near Connolly's Plot, the world's first teak plantation, Heiko waded into a narrow creek that joined the main flow.

Sinking chest-deep into soft soil, he collected:

• Mesonoemacheilus herrei

• Lepidocephalichthys berdmorei

• A dark form of Carinotetraodon travancoricus

• Juveniles of Macrognathus guentheri To him, the quiet tributary appeared to serve as a breeding refuge where several species could spawn undisturbed.

The Princess of Kerala

Further south, in the Thootha (Thuda) River, a tributary of the Kunthi River, Heiko found the celebrated Sahyadria denisonii, the Princess of Kerala, in large numbers. They spawned in rock crevices beneath overhanging Cryptocoryne retrospiralis. Water parameters were recorded as 31.4°C, pH 7.1, conductivity 64 µS/cm. Alongside them were: Dawkinsia filamentosa, golden Carinotetraodon travancoricus, Aplocheilus lineatus, Mesonoemacheilus triangularis, Awaous grammepomus, and Sicydium griseus. Heiko's data contradicted published reports claiming S. denisonii occurred in only nine rivers. He had documented it in twenty-one of thirty-seven. Moreover, he noted that most fish in the aquarium trade were already kept abroad in Southeast Asia, while much less information existed on their natural habitat.

Faith and Fieldwork

In Thrissur, Heiko visited the fish market, where Etroplus suratensis - a cichlid admired worldwide - was sold for food. That evening he joined the Thottam Pattus Mahotsavam, a festival dedicated to the Snake Gods. At the Kollayi Shree Bhadra Devi Temple, under an immense banyan tree, families gathered with lamps and music. Heiko described being given a herbal paste by the priest and receiving a blessing with a ceremonial sword. Field notes combined ichthyology and local tradition so naturally; it reflected his respect for the people who lived beside the waters he studied.

The Chalakudy River

Heiko's next stop was the Chalakudy River, one of Kerala's major systems. Its 169-kilometre course begins in the Anamalai Hills and joins the Periyar River before reaching the Arabian Sea. Here he studied two closely related species - Sahyadria denisonii and S. chalakkudiensis - and observed that the latter was nocturnal, larger, and solitary, with orange tail stripes instead of white. He wondered whether these adaptations offered protection from predators or reflected older evolutionary traits. Nearby he documented Horabagrus nigricollaris, another nocturnal species, and in the rapids of the Vazhachal Falls, the hill-stream loach Travancoria elongata.

His notes also recorded pressures on the river:

• Deforestation

• Sand mining

• Dams

• Saline intrusion

• Invasive species such as Oreochromis mossambicus, Gambusia affinis, Osphronemus goramy, Xenophorus maculatus, and Poecilia reticulata The latter was found even at 1,050 metres elevation.

"These are the ones which can do real damage to this biodiversity hotspot," he wrote, before ending the paragraph abruptly- a rare moment of visible frustration.

Reflections from His Journeys

Reading these pages, I began to understand how Heiko worked. Each trip combined scientific precision with a curiosity that refused boundaries. He recorded pH, conductivity, and temperature as carefully as he noted the people, rituals, and histories around each site. His accounts of India are neither romantic nor detached; they are field observations written by someone deeply aware of how fragile these ecosystems are. Many of the habitats he described have since changed, yet his data remain a benchmark for anyone studying the freshwater fauna of the region.

Why His Work Matters

For Indian aquarists, Heiko's Biotopes is more than a reference - it is documentation of our natural heritage. Heiko showed that native species like sahyadria, dawkinsia, etroplus, and barilius deserve the same recognition as imported ones. His work preserves a snapshot of our rivers before modern pressures took hold, a reminder of what once existed and what still can be saved.

Continuing the Journey

That afternoon in Italy feels recent still. I met Heiko, Natasha, and Amanda - and unknowingly brought home their legacy. Bleher's Biotopes remains a book I return to often, not only for information but for perspective. It reminds me that behind every fish we keep lies a habitat, a story, and a responsibility.

Read the full story

The complete feature follows Heiko Bleher's expeditions through India's rivers and streams, documenting fish, aquatic plants, habitats, field observations and the people and traditions encountered along the way. Read the complete story in the October 2025 issue of The Weekend Aquarist.

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