The Indonesian coelacanth (Latimeria menadoensis) is one of the most enigmatic and evolutionarily significant marine vertebrates on the planet. Coelacanth often referred to as a "living fossil.
This deep-sea fish closely resembles its ancestors from the Cretaceous period and was thought to have been extinct for 65 million years. However, a groundbreaking discovery in October 2024 has expanded our understanding of this species. This also marks the first record of a living coelacanth in the waters of North Maluku, Indonesia.
The Discovery of the Indonesian Coelacanth
The story of the Indonesian coelacanth began in 1997 when researchers Mark and Arnaz Erdmann first spotted the fish at a market in Manado, North Sulawesi. It was officially described as a distinct species from its African relative, Latimeria chalumnae, in 1999.
While the African species is found in the West Indian Ocean, the Indonesian variety was initially thought to be endemic to the Sulawesi region and parts of Western New Guinea. For decades, sightings were extremely rare, occurring primarily through accidental bycatch or via submersibles and Remotely Operated Vehicles (ROVs) at great depths.
According to a scientific journal titled First record of a living coelacanth from North Maluku, Indonesia published in Scientific Reports (2025) by Alexis Chappuis and his colleagues, the understanding of this species' range has changed dramatically. In October 2024, researchers Alexis Chappuis and Julien Leblond utilized technical diving with closed-circuit rebreathers and trimix breathing gases to explore mesophotic coral ecosystems.
At a depth of 144 meters along a steep volcanic slope, they encountered an adult coelacanth approximately 1.1 meters in length. This was a historic event, as it represented the first in situ observations made by divers of an Indonesian coelacanth.
The team successfully identified the same individual on a subsequent dive by its unique white dot pattern, which acts as a natural "fingerprint" for the species.
The Evolution of the Living Fossil: Unexpected Behavior
Coelacanths are lobe-finned fish (sarcopterygians) and are the closest living relatives to tetrapods, alongside lungfish. They possess unique morpho-anatomical features, including unpaired lobed fins that look like paired fins and a highly modified lung or swim bladder.
The North Maluku specimen displayed fascinating behavior, hovering in the open above a rock rather than hiding in a cave, which was previously thought to be their primary diurnal habitat. The fish used its second dorsal, anal, pectoral, and pelvic fins independently to maintain its position in the water. These fish prefer cold-water environments, typically below 21°C, the North Maluku site recorded temperatures between 19°C and 20°C.
Highly Vulnerable Species
The discovery in North Maluku suggests that the Indonesian coelacanth may have a much broader distribution range than previously realized, potentially spanning the entire archipelago between Sulawesi and Western New Guinea.
Despite this good news, the species remains highly vulnerable. Coelacanths are characterized by a low metabolic rate, late sexual maturity, and a long gestation period, making them sensitive to external pressures.
Current threats include anthropogenic activities and the potential rise of unregulated tourism. To protect this potential new population, the exact coordinates of the sighting have been withheld until formal protections are established.
This fantastic discovery of ‘living fossil” brings great hope that the national authorities would increase conservation efforts in this marine biodiversity hotspot.
