In a discovery that’s making waves among marine biologists, divers in Indonesia have captured the first underwater photographs of a living Sulawesi coelacanth — Latimeria menadoensis — a species often referred to as a “living fossil” due to its ancient evolutionary roots.
The rare footage, published in Scientific Reports, was recorded by deep technical divers Alexis Chappuis and Julien Leblond during a descent off the coast of North Maluku, Indonesia. The coelacanth, a prehistoric fish with lobed fins and a slow-motion drift, was spotted at a depth of 144 meters, hovering silently over a volcanic slope. It’s the first time this species has been filmed in situ by humans, marking a milestone in marine exploration and evolutionary research.
“We’ve seen shapes on sonar, vague silhouettes from ROVs,” said Chappuis. “But to look it in the eye, to hover just meters from it — that’s different. That’s history alive.”
An Ancient Survivor in a Modern World
Coelacanths were long presumed extinct until a chance discovery in 1938 off South Africa challenged the textbooks. Since then, two species have been identified: Latimeria chalumnae, found in the western Indian Ocean, and L. menadoensis, first discovered in a fish market in Sulawesi in 1997.
What makes coelacanths so intriguing isn’t just their rarity, but their evolutionary significance. Part of the Sarcopterygii clade, or lobe-finned fishes, they share a closer genetic relationship with land vertebrates — including humans — than with modern bony fishes. Fossil records suggest their lineage stretches back over 400 million years, making them older than dinosaurs, flowering plants and even insects.
The fish caught on camera was around 1.1 meters long, with a dorsal fin held erect throughout the encounter — a possible sign of alertness or active behavior. Researchers believe it may have been using its lobed fins to stabilise in the cold, calm current, where temperatures hovered around 19 to 20°C — significantly cooler than the 29–30°C surface waters.
A Fragile Existence in the Mesophotic Twilight
The coelacanth’s habitat lies in what’s known as the mesophotic zone — a deep-water band between 200 to 500 meters, where sunlight fades but coral life persists. It’s an ecosystem often overlooked but vital, especially for ancient species with low reproductive rates and long lifespans.
Coelacanths mature at around 40 years, and pregnancies can last up to five years, according to scale studies and data from FishBase. Their slow metabolism, enabled by cold deepwater conditions, helps them conserve energy — but also makes them extremely vulnerable to changes in habitat or sudden population loss.
The specimen seen by Chappuis and Leblond was likely resting or foraging when discovered. Unlike previous assumptions that coelacanths hide in caves during the day, this one was in open water, a behavior also noted in earlier ROV surveys in Indonesia, challenging longstanding beliefs about their daily patterns.
Why This Matters — and What Happens Next
The Maluku sighting suggests L. menadoensis may have a broader distribution than previously assumed. Until now, confirmed populations were limited to Sulawesi and parts of Papua, with scattered sightings and bycatch reports. This latest find fills a geographic gap and hints at the possibility of unidentified populations between the islands.
But with discovery comes risk. Conservationists warn that media attention could lead to unregulated eco-tourism, putting further strain on an already fragile population. The IUCN Red List currently lists L. menadoensis as Vulnerable, and its African cousin as Critically Endangered. Industrial fishing, plastic pollution and deep-sea mining all pose credible threats.
Chappuis and his team plan to return in 2026 with non-invasive sampling tools, including environmental DNA swabs to test whether Maluku’s coelacanths form part of a larger metapopulation or are genetically distinct. These insights could inform marine protected area (MPA) boundaries and seasonal fishing regulations.
“Protecting this fish isn’t about nostalgia,” said Dr. Gino Limmon, co-author of the Scientific Reports study. “It’s about recognising that the deep sea still holds critical biodiversity — and some of it is hanging by a thread.”
In response, Indonesia’s Ministry of Marine Affairs is reportedly drafting new guidelines to establish protected zones across deep reef ecosystems, though implementation will depend on regional funding and local cooperation.
