Indonesian coelacanth (Latimeria menadoensis) is some of the enigmatic and evolutionarily significant marine vertebrates on our planet. The coelacanth is commonly called a “living fossil.”
This deep-sea fish closely resembles its ancestors from the Cretaceous period and is believed to have been extinct for 65 million years. However, a breakthrough discovery made in October 2024 has expanded our knowledge of this species. This can be the primary record of a living coelacanth within the waters of the North Maluku Islands, Indonesia.
Discovery of the Indonesian Coelacanth
The history 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 separate species from its African relative Latimeria chalumnae in 1999.
Although the African species is present in the western Indian Ocean, the Indonesian variety was initially regarded as endemic to the Sulawesi region and parts of western New Guinea. For a long time, sightings were extremely rare, mostly in consequence of accidental bycatch or via submarines and remotely operated vehicles (ROVs) at great depths.
According to the scientific journal entitled First record of a living coelacanth from the North Maluku Islands, Indonesia published in Scientific reports (2025) by Alexis Chappuis and his colleagues, the understanding of this species’ range has modified dramatically. In October 2024, researchers Alexis Chappuis and Julien Leblond used technical diving with closed-circuit rebreathers and trimix respiration gases to review mesophotic coral ecosystems.
At a depth of 144 meters, on the steep slope of the volcano, they encountered an adult coelacanth about 1.1 meters long. It was a historic event since it was the primary on site observations made by divers of the Indonesian coelacanth.
On a subsequent dive, the team managed to discover the identical individual based on its unique pattern of white dots, which is a natural “fingerprint” for this species.
The evolution of a living fossil: unexpected behaviorR
Coelacanths are finned fish (sarcopterygians) and, next to lungfish, are the closest living relatives of tetrapods. They have unique morphoanatomical features, including unpaired lobed fins that appear to be paired fins and a highly modified lung or swim bladder.
The North Maluku specimen exhibited fascinating behavior by floating within the open above a rock fairly than hiding in a cave, which was previously regarded as their principal daytime habitat. The fish independently used its second dorsal, anal, pectoral and ventral fins to keep up its position within the water. These fish prefer cold water environments, typically with temperatures below 21°C, and temperatures of 19°C to twenty°C have been recorded in northern Maluku.
Very sensitive species
The discovery within the North Maluku Islands suggests that the Indonesian coelacanth can have a much wider range than previously thought, potentially covering the complete archipelago between Sulawesi and western New Guinea.
Despite this excellent news, the species stays very vulnerable. Coelacanths have a low metabolic rate, late sexual maturity, and an extended gestation period, which make them sensitive to external pressures.
Current threats include anthropogenic activities and the potential development of unregulated tourism. To protect this potential recent population, precise sighting coordinates have been withheld until formal safeguards are established.
This unbelievable discovery of a “living fossil” gives great hope that national authorities will increase their efforts to guard this marine hotspot of great biodiversity.
