Deep in the heart of Cuba’s Zapata Swamp—a vast wetland recognized by UNESCO as a Biosphere Reserve—an ancient survivor is fighting for its life. The manjuarí, known to scientists as Atractosteus tristoechus, is a prehistoric fish whose lineage stretches back more than 140 million years. Once a thriving symbol of Cuban biodiversity, it now teeters on the edge of extinction, its fate intertwined with the fragile ecosystem it calls home.
This remarkable species, often described as a "living fossil," has endured countless geological and climatic upheavals. But as of November 24, 2025, the manjuarí is critically endangered in the Zapata Swamp, the largest wetland in the Caribbean. According to Reuters, the International Union for Conservation of Nature (IUCN) added the manjuarí to its Red List as "critically endangered" in 2020, a grim milestone for a creature that has survived since the age of the dinosaurs.
What went wrong for the manjuarí? The answer, as reported by multiple sources, is a perfect storm of human-driven threats. Habitat loss has steadily chipped away at the swamps and waterways the fish needs to breed and feed. Indiscriminate hunting has further thinned its numbers. But perhaps the most devastating blow came in 1999, when the Cuban government introduced the African walking catfish (Clarias gariepinus)—popularly called "claria"—as a food source. The intention was to boost aquaculture and provide a resilient protein for the nation. Instead, the claria became a voracious invasive species, upending the delicate ecological balance of Cuba’s freshwater environments.
According to Reuters, the claria has devastated native aquatic ecosystems, wiping out endemic fish and other native species, including those inhabiting rivers and underground systems. The manjuarí, already rare, was pushed to the brink as it was outcompeted and displaced from its last strongholds. The presence of the claria now coincides with a noticeable degradation of the manjuarí’s habitat, a crisis echoed in official Cuban reports and conservation agency warnings.
In the face of these daunting challenges, a small group of Cuban biologists has refused to give up. Led by Andrés Hurtado, their team is spearheading a controlled breeding project in a modest hatchery surrounded by mangroves within the Zapata Swamp. Their work is both painstaking and precarious. The manjuarí is an elusive creature, notoriously difficult to observe and extremely sensitive to environmental changes. Its larvae, barely the size of a pencil, hide among the tangled roots of the mangroves, making them nearly impossible to monitor and protect.
Yet there is a glimmer of hope. Hurtado’s team has successfully bred young manjuarí in captivity and released them back into the wetland in an effort to repopulate their natural habitat. The process is far from simple; it is hampered by a lack of supplies, the isolation of the breeding facility, and the ever-present threat of predators. Still, the persistence of these scientists is starting to pay off. Local fishermen have recently reported sightings of the manjuarí in areas where the fish had not been seen for years—a sign that the population, while precarious, may be holding on.
But the obstacles remain formidable. Supplies are scarce, and the isolation of the Zapata Swamp complicates every aspect of the project. The introduction of invasive predators like the African catfish continues to threaten not just the manjuarí, but the entire web of life in Cuba’s wetlands. According to Reuters, the situation is further complicated by a lack of coherent environmental policy and the ongoing degradation of habitats across the island.
For many Cuban scientists and conservationists, the fight to save the manjuarí is about more than just preserving a species. It is a battle to protect a unique piece of the island’s natural heritage. "The manjuarí is a living fossil and a symbol of Cuban biodiversity," specialists assert, calling for greater institutional support and public awareness. They argue that the recovery of the manjuarí is not merely an environmental issue, but a matter of national pride and legacy—a chance for Cuba to demonstrate its commitment to conservation in the face of daunting odds.
The urgency of the situation was underscored recently when two manjuarí specimens were found dead in the streets of Havana. The cause of their deaths remains unclear, but the incident sent shockwaves through the scientific community, highlighting just how vulnerable this ancient fish has become. Biologists and environmentalists sounded the alarm, warning that without swift and coordinated action, the manjuarí could disappear forever.
Unfortunately, the manjuarí is not alone in its plight. Official figures indicate that the number of endemic Cuban fauna in danger has increased in recent years, with invasive species, habitat loss, and insufficient environmental policies cited as the main drivers. The international conservation community is watching closely, with many experts applauding the innovative restoration attempts led by Hurtado’s team. Some hope that these efforts could serve as a model for other endangered species facing similar threats from invasive predators and ecosystem disruption.
What makes the manjuarí’s story so compelling is its status as a "biological relic"—a creature that has survived millions of years, only to face its greatest threat in the modern era. The fish’s survival is now a test of Cuba’s resolve and ingenuity. Will the nation rise to the challenge and save this living link to its prehistoric past?
As the sun sets over the mangroves of the Zapata Swamp, the fate of the manjuarí hangs in the balance. The dedicated work of biologists like Andrés Hurtado offers hope, but time is running out. If Cuba can rally the institutional support and resources needed to protect its natural heritage, the manjuarí may yet swim free in its ancestral waters for generations to come.
