On today’s show we learn about the Bandula Barb, a critically endangered freshwater fish native to South Asia, specifically western Sri Lanka near Galapitamada in the Kelani river basin.
Rough Transcript
Intro 00:05
Welcome to Bad at Goodbyes.
On today’s show we consider the Bandula Barb.
Species Information 02:05
The Bandula Barb is a critically endangered freshwater fish native to South Asia, specifically western Sri Lanka near Galapitamada in the Kelani river basin. Its scientific name is Pethia bandula and it was first described in 1991.
Description
It is a small fish, measuring 1.5 to 2 inches in length, like roughly the size of your thumb. Their scales have either a reddish-gold, or yellow gold coloration, marked by two black vertical stripes, one near the operculum, that’s the hardened protective gill-cover near the head and the other stripe is near the rear, just before the tail fin.
They have seven fins, two pectoral fins, one on each side of the body just below the gills. A pair of pelvic fins on the underside of the body, an anal fin on the underside to the rear, a caudal fin, caudal is the scientific name for the tail fin. And on its back, a dorsal fin that is hardened and serrated along its back edge. All of the fins are a deep grey-black except for the caudal fin (the tail fin) which tends to be a lighter version of their base color that fades to completely translucent, see-through at the edges.
Behavior
The Bandula Barb is benthopelagic, meaning they live and forage both near the stream bed (the benthic zone) and in the water above (the pelagic zone), though in this case that is not like a huge range. The species is found in the shallowest parts of its habitat, in waters less than 8 inches deep. And they do not migrate, completing their entire life cycle within the roughly 2 mile confines of their native stream, in which they prefer slow-moving, cooler shaded waters.
The Bandula Barb is primarily herbivorous, plant-eating, feeding on algae and microalgae. They are active foragers, actively moving throughout their homewaters to graze algae from submerged rocks, decaying leaf litter on the stream bed, and from the root systems of aquatic and streamside plants.
They do not have teeth in their mouths, instead, they have specialized teeth in their throat called pharyngeal teeth. They also do not have stomachs; so food is ground up by the pharyngeal teeth and passes into a short esophagus that connects directly to their intestines. So, instead of being broken down in a stomach, nutrients are absorbed as the food moves through the intestines. And then waste is expelled from the cloaca, a digestive and reproductive opening near the anal fin.
Reproduction
The Bandula Barb is a perennial spawner, meaning it reproduces throughout the year, with two major spawning peaks from August to December, and February to March. These time periods are roughly opposite western Sri Lanka’s monsoon season, which is May to September.
I could find no recorded observation of courtship behaviors, though males in closely related species like the Black Ruby Barb do perform a kind of display for the female, spreading fins and swimming around a potential mate for extended periods.
Reproduction occurs via external fertilization, the female releases eggs into the water to be fertilized by the male. The hundreds of eggs are deposited into the shallow edges of the stream among aquatic plants and root systems that provide protection and surfaces for the eggs to adhere to. After spawning is complete, the parents provide no protection or care for the eggs or the resulting offspring. Though not specifically documented, research suggests that the young reach reproductive maturity within 15 months.
In The Dream
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In the dream
To have a perfect home. A small apartment where every chair is the right height and the bed is soft, but not mushy. There’s bookshelves and big windows and a place to sit and stare out the window and dream. And the cupboard is stocked with soba noodles, and popcorn and porridge, dried mango, red lentils and quinoa. And the fridge has fruit and vegetables and greens, exactly the amount we need between now and the next farmers market. And there are notebooks to make lists and write poems in, and all of our things have a place and the bits that are messy are messy in the ways we like messy to be. And there something else, ineffable, just that a perfect home has to feel like home.
And then one day, through no fault of one’s own. It’s gone. It’s gone and there’s nowhere to go.
In the dream.
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Habitat
The Bandula Barb is native to western Sri Lanka, in the Sabaragamuwa Province, near Galapitamada in the Kelani River Basin; this is roughly 25 miles north-east of Colombo and the coast.
The Bandula Barb is considered a point endemic species, a species with a single population, restricted to a single location, one highly specific ecosystem where it can survive.
In our case, our Bandula Barb is found only in a roughly 2 mile stretch of a tiny shallow unnamed tributary, that eventually feeds the Kelani River. The unnamed stream flows through a landscape encroached upon and transformed by human activity, passing near three small villages, through backyard gardens, rice fields, rubber plantations, secondary growth forests and near road construction.
Here, the Bandula Barb is found in slow-moving waters, with a stream bed of silt, sand, small rocks and decaying leaf and plant matter. Aquatic plants clump in the water and stream banks are lined with trees, vegetation and grasses. The Bandula Barb prefers shade; researchers have documented greater abundance and congregation in cooler waters, out of direct sunlight.
Before human encroachment, the Barb’s stream flowed through a rolling, hilly terrain covered by tropical lowland rainforest, tall Dipterocarp trees with lush understories. And while pockets of that rainforest ecosystem do remain in the region, it is fragmented by, predominantly, agricultural land use.
This is a tropical monsoon climate, with highs in the warmest months reaching into the 90s°F and with the colder months dipping into the 70s°F. It sees over 90inches of rainfall per year.
The Bandula Barb shares its habitat with:
Brown Snakehead, Black Ruby Barb, Giant Danio, Rock Frog, Redside Barb, Water Lily, Long-snouted Barb, Java Moss, Water Beetle, Rubber Tree, Common Rasbora, Asoka Barb, Water Trumpet, Common Spiny Loach, Ketala, Sri Lanka Birdwing, Kumbuk, Ceylon Rose Butterfly, Bamboo, and many many more.
Threats
As mentioned, human encroachment and habitat transformation, destruction and fragmentation are the primary drivers of Bandula Barb population loss. Its habitat has seen a near total transformation, first deforestation then agricultural development: rice paddies and rubber plantations.
Deforestation specifically affects the Barb as it removes the waterborne root systems that protect their spawning sites; it decreases leaf litter and other organic debris in the water that promotes algae growth (their food); Fewer trees decreases shade and increases water temperature, these are habitat restrictions for the Bandula Barb. And deforestation also increases the rate of soil erosion, and the speed of water flow, both factors that affect successful egg-laying and reproduction.
Historically agricultural development has exposed the Bandula Barb’s water habitat directly to chemical runoff. The use of pesticides and fertilizers in the surrounding rice paddies and rubber plantations pollutes the streamwater, altering the water chemistry and proving lethal to the fish and their food.
Human induced climate change is an increasing threat. Western Sri Lanka is already seeing disrupted weather patterns of heavier rainfalls and also longer dry seasons. More rain results in faster water flow that disrupts the Barb’s spawning; longer periods of drought threaten to seasonally dry up the Barb’s habitat altogether.
Conservation
Fortunately the Bandula Barb has seen significant and remarkable conservation activity. In 2014 the IUCN in collaboration with the Sri Lankan Ministry of Environment, the Department of Wildlife Conservation, the Forest Department, and local communities initiated a species recovery plan. This included an education program for local residents and for the local agriculture industry which resulted in the adoption of organic farming techniques that have mitigated chemical pollution run-off into the stream. Locals have also been reforesting the stream’s banks.
In 2014 a translocation program successfully moved a small portion of the population to nearby waters in the Wilikulakanda Proposed Forest Reserve and that population is naturally spawning and thriving.
And recently in June 2025, the government declared the Bandula Barb’s original habitat a protected wilderness site.
Nevertheless the Bandula Barb has been considered critically endangered on the IUCN Red List since 1996 and their overall population is in decline.
Our most recent counts estimate that less than 1400 Bandula Barb remain in the wild.
Citations 22:56
Information for today’s show about the Bandula Barb was compiled from:
Chamod, Janindu & Amarakoon, Vihanga & Gunasekara, Vimukthi & Dayawansa, Nihal. (2023). The Role Of Selected Abiotic And Biotic Factors In Changing The Abundance Of Critically Endangered, Point Endemic Pethia Bandula. Proceedings of the Postgraduate Institute of Science Research Congress: University of Peradeniya, Sri Lanka
Fernado, M., Kotagama, O. & de Alwis Goonatilake, S. 2019. Pethia bandula (errata version published in 2020). The IUCN Red List of Threatened Species 2019: e.T18905A174839322. - https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T18905A174839322.en
Kortmulder, Koenraad & Wiele, Peter. (2023). Feeding behaviour, species associations and natural diets of 10 Cyprinid fish species from South-West Sri Lanka. bioRxiv 2023.07.12.548677 – https://doi.org/10.1101/2023.07.12.548677
R, Wickremasinghe & S, Muthunayake & R, Wickremasinghe & Weerakoon, Devaka & Goonatilake, Sampath & R, Ranatunge & H, Kiel & Perera, Naalin & A, Wadugodapitiya. (2021). Ecology and recovery of Pethia bandula (Pisces: Cyprinidae), a globally threatened point endemic freshwater fish in Sri Lanka.. Journal of the Sri Lanka Branch of the Royal Asiatic Society. 66 (2). 27-54. https://www.jstor.org/stable/48828122
Sudasinghe, H., Ranasinghe, T., Herath, J. et al. Molecular phylogeny and phylogeography of the freshwater-fish genus Pethia (Teleostei: Cyprinidae) in Sri Lanka. BMC Ecology and Evolution volume 21, 203 (2021). – https://doi.org/10.1186/s12862-021-01923-5
Surasinghe, Thilina, Ravindra Kariyawasam, Hiranya Sudasinghe, and Suranjan Karunarathna. 2020. “Challenges in Biodiversity Conservation in a Highly Modified Tropical River Basin in Sri Lanka” Water 12, no. 1: 26. – https://doi.org/10.3390/w12010026
Wickramasinghe, Kamanthi. 6 June 2025. Sri Lanka reaches a milestone in a decades’ long conservation effort. Daily Mirror (Sri Lanka) – https://www.dailymirror.lk/news-features/Sri-Lanka-reaches-a-milestone-in-a-decades-long-conservation-effort/131-310807 or https://web.archive.org/web/20251005015550/https://www.dailymirror.lk/news-features/Sri-Lanka-reaches-a-milestone-in-a-decades-long-conservation-effort/131-310807
Wikipedia – https://en.wikipedia.org/wiki/Bandula_barb
Music 24:25
Pledge 30:38
I honor the lifeforce of the Bandula Barb. I will commit its name to my record. I am grateful to have shared time on our planet with this being. I lament the ways in which I and my species have harmed and diminished this species. I grieve.
And so, in the name of the Bandula Barb I pledge to reduce my consumption. And my carbon footprint. And curb my wastefulness. I pledge to acknowledge and attempt to address the costs of my actions and inactions. And I pledge to resist the harm of plant and animal kin and their habitat, by individuals, corporations, and governments.
I forever pledge my song to the witness and memory of all life, to a broad celebration of biodiversity, and to the total liberation of all beings.
