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Muséum d'Histoire Naturelle de Nantes.Cœlacanthe Latimeria chalumnae Le spécimen du Muséum de Nantes est pêché aux Comores, dans la nuit du 25 au 26 septembre 1968 à 1 km du rivage, par 150 m de fond. Il s'agit d'un mâle

West Indian Ocean coelacanth

Rare deep-sea fish with blue scales and limb-like fins.

Photo: sybarite48, CC BY 2.0, via Wikimedia Commons

This rare vertebrate lives in deep western Indian Ocean waters. Scientists first identified it in 1938 after a trawler catch in South Africa. It is closely related to lungfish and land animals. The species faces critical endangerment due to low numbers and accidental capture.

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  • Grows up to 2 metres long and weighs 95 kg
  • Lives in deep underwater lava caves
  • Performs headstands to feed on prey
  • First scientifically described in 1938
  • Listed as Critically Endangered by IUCN

What it is

This fish belongs to an ancient order of vertebrates. It has a robust body covered in vivid blue scales with white spots for camouflage. Adults grow up to two metres long and weigh nearly one hundred kilograms. Its fins move like limbs, allowing complex motion. Large eyes help it see in dark water. A reflective layer behind the retina boosts light absorption. It retains urea in its blood to balance internal pressure, similar to sharks.

Where it lives

Populations live along the western Indian Ocean coast. They inhabit waters from South Africa north to Kenya and Tanzania. Significant groups reside near the Comoro Islands and Madagascar. These fish dwell in underwater lava caves. They stay at depths between seventy and seven hundred metres. Most sightings occur between one hundred and two hundred metres deep. The environment is dark and cool, suited to their physiology.

How it lives

They rest in caves during the day to avoid predators. At night, they hunt in surrounding areas. Their diet includes various small reef fish. Uniquely, they can perform headstands to suck prey from crevices. This action uses a hinged skull joint. They have mobile upper and lower jaws. Visual cells called rods help them navigate low-light conditions. They are opportunistic hunters rather than active chasers.

Breeding and life cycle

Females carry eggs inside their bodies until they hatch. This method is called ovoviviparity. The gestation period lasts about twelve months. They produce few young due to this long development time. Scientists do not know when they reach sexual maturity. Low reproductive rates make population recovery slow. Each birth likely yields only a few fully formed juveniles.

West Indian Ocean coelacanth
A drawing made by EveryFish from what this page says. It is a diagram, not a picture of the real fish.

Fish and people

Fishermen in the Comoros knew this fish as gombessa. Science recognized it only after a 1938 catch in South Africa. Marjorie Courtenay-Latimer identified the strange blue specimen. Professor J. L. B. Smith named it after her. It was once thought unchanged since prehistoric times. Genetic studies now show lungfish are closer to land animals. The genome was sequenced in 2013 for evolutionary research.

Status and threats

The species is critically endangered. Estimates suggest fewer than five hundred individuals remain. Accidental catches by deep-sea fishermen threaten survival. A thirty percent population drop occurred in the early 1990s. International trade is banned under CITES Appendix I. Permits are required for any movement of specimens. Small colonies exist, making them vulnerable to local threats.

Coelacanth 69 m off Pumula on the KwaZulu-Natal South Coast , South Africa, on 22 November 2019 (photo: Bruce Henderson)
Coelacanth 69 m off Pumula on the KwaZulu-Natal South Coast , South Africa, on 22 November 2019 (photo: Bruce Henderson). Photo: Bruce A.S. Henderson, CC BY 4.0, via Wikimedia Commons
East London Museum, Oxford Street, Belgravia, East London, Eastern Cape, SOUTH AFRICA
East London Museum, Oxford Street, Belgravia, East London, Eastern Cape, SOUTH AFRICA. Photo: Bernard DUPONT, CC BY-SA 2.0, via Wikimedia Commons
The second coelacanth ever caught in 1952, with J.L.B. Smith, surrounded with the crew and airmen who flew Smith to the Comoros on order by prime minister D.F. Malan. Image reprinted in Mail & Guardian . Location: South
The second coelacanth ever caught in 1952, with J.L.B. Smith, surrounded with the crew and airmen who flew Smith to the . Photo: Unknown author, Public domain, via Wikimedia Commons
The density gradient is colorized from brown to white in ascending order. (A) dorsal view of entire head (left) and isolated skeleton (right). (B) lateral view of entire head (left) and isolated skeleton (right). (C) ven
The density gradient is colorized from brown to white in ascending order. (A) dorsal view of entire head (left) and isol. Photo: Luigi Manuelli, Jorge Mondéjar Fernández, Kathleen Dollman, Kudakwashe, CC BY 4.0, via Wikimedia Commons

Questions people ask about West Indian Ocean coelacanth

Is the coelacanth really a living fossil?

It was once thought to be evolutionarily static. However, recent discoveries show morphological diversity. Genetic sequencing proves lungfish are closer to tetrapods. The term remains popular but scientifically nuanced.

Where does the West Indian Ocean coelacanth live?

It inhabits deep underwater caves in the western Indian Ocean. Range includes South Africa, Mozambique, Tanzania, Kenya, Comoros, and Madagascar. Depths vary from 70 to 700 metres.

Why is the coelacanth blue?

The vivid blue colour with white spots acts as camouflage. It helps the fish blend into the dark deep-sea environment. This coloration aids in hunting prey without detection.

How do coelacanths reproduce?

They are ovoviviparous, meaning eggs hatch inside the mother. Gestation lasts around twelve months. This long period results in low fecundity and few offspring per birth.

Good reading and sources

Where this page comes from

The facts on this page come from the Wikipedia article "West Indian Ocean coelacanth", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.

It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.

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The small pictures above come from Wikimedia Commons under free licences. Some are cropped to fit.

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