Encountering the Giant Dinosaur Fish: Face to Face with the Coelacanth

Name: Encountering the Giant Dinosaur Fish: Face to Face with the Coelacanth
Start: 2025-09-15T18:45:00+08:00
End: 2025-09-15T20:30:00+08:00
Location: Hkma Fairmont House

Schedule

Mon Sep 15 2025 at 06:45 pm to 08:30 pm

UTC+08:00

Location

Hkma Fairmont House | Hong Kong, HK

A Quest at Great Depth to document the giant “Dinosaur” Fish fromwhich all Terrestrial Vertebrates are Descended
In October 2024, diving at 145 metres, Alexis Chappuis “met” a giant fish-like sea creature that has changed biology for ever. The Coelacanth is among the most elusive, yet emblematic marine creatures. Thought to be extinct for 70 million years, it is the missing link that allowed the vertebrates to transition from underwater to terrestrial life.
In this talk, Alexis tells the story of a scientific and human adventure that started more than 10 years ago. He started documenting deep-reef biodiversity to raise awareness about one of the least-protected habitats on Earth: the so-called mesophotic coral ecosystems, home to thousands of unique species thriving at human-hostile depths. This quest led to his encounter of a lifetime, 145 metres below the surface.
When a living coelacanth was found in 1939 off the coast of South Africa, it was considered the most significant zoological discovery of the 20th century. In 1997, a new bombshell hit the scientific community when a specimen was discovered in a fish market in the northern part of the island of Indonesia, a second species, the Sulawesi Coelacanth.
The Indonesian species had never been encountered, let alone photographed, by a diver yet until Alexis set out on a deep dive in October 2024. With a home at depths way past usual diving limits, only a few divers had attempted to meet Indonesian coelacanths, and in vain. But, on that day in 2024, this all changed.

Alexis Chappuis is a French marine biologist and has a Masters in Marine Biology. He is a National Geographic Explorer and technical scientific diver, who has been working in Indonesia since 2014. In 2018, he founded UNSEEN Expeditions, an NGO focusing on exploring and documenting mesophotic coral ecosystems – at depths of 100 to 160 metres – in Southeast Asia, particularly Indonesia. Alexis's work involves collaborating with local and international scientists to study these poorly-known and poorly-protected deep-reef habitats, using closed-circuit rebreathers. In 2024, he and his team discovered the first coelacanth of the Maluku archipelago, Indonesia, and he became the first diver to photograph this species, Latimeria menadoensis, in its natural habitat, at a depth of 145 metres.

Members of the RGS, their guests and others are most welcome to attend this event, which is HK$200 for RGS Members and HK$250 for guests and others. This talk is free of charge for student members.

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The opinions expressed at this event are those of the speaker and do not necessarily reflect those of the Royal Geographical Society - Hong Kong.