West Indian Ocean coelacanth

Coelacanths hunt at night.

They eat squid, cuttlefish and fish. A special sense in their snout helps them find food in the dark.

Coelacanths rest in caves during the day and come out at night to hunt. They eat cuttlefish, squid and fish.

They have an amazing way of finding food. Inside the snout is a special organ that scientists think can sense the tiny electric signals that other animals give off. A hinge inside the skull also lets a coelacanth open its mouth especially wide.

Coelacanths leave their daytime caves at night to hunt cuttlefish, squid and fish. The rostral organ in the snout is thought to detect the weak electrical impulses produced by prey.

Feeding is helped by the intracranial joint, a hinge within the skull that lets the mouth open especially wide; the Natural History Museum notes that this feature is not seen in any other living vertebrate.

Coelacanths rest in dark caves in the daytime.

At night they come out. They drift slowly with the moving water. Sometimes they even stand on their heads!

Coelacanths spend the day sheltering in caves and come out at night to hunt. When the scientist J.L.B. Smith saw their leg-like fins, he guessed they might walk on the sea floor.

When scientists finally watched them in the wild, they found that coelacanths do not walk. They drift with the current, holding their body and tail stiff, and use their fins to steer. Their paired fins move in the same pattern as the legs of a walking reptile. They have even been seen doing headstands, hanging head-down for several minutes.

By day coelacanths shelter in caves; at night they forage. Smith predicted they would use their lobed fins to walk on the seabed, but observations show they typically drift with the current, body and tail held rigid. The sail-like first dorsal fin and the lobed fins stabilize and turn the fish, and the lobed fins also help propel it; diagonal pectoral and pelvic fins work in tandem, like the legs of a walking reptile.

Coelacanths have also been observed performing 'headstands', rotating to a vertical, head-down position and holding it for several minutes. The behavior is linked to the rostral organ in the snout, which is thought to detect the weak electrical impulses of prey.

In 1938 a museum worker in South Africa saw a strange blue fish.

It had been caught in a fishing net. A fish scientist said it was a coelacanth. People all over the world were amazed.

On 22 December 1938, Marjorie Courtenay-Latimer, the curator of the East London Museum in South Africa, saw an unusual fish that had been caught in a fishing net. It was 1.5 meters long, with shiny blue scales and strange, fleshy fins.

She wrote to J.L.B. Smith, a fish expert at Rhodes University, and sent a drawing. When Smith saw the fish in February 1939, he was certain: it was a coelacanth. He named it Latimeria chalumnae, after Courtenay-Latimer and the Chalumna River, near where it was caught.

On 22 December 1938 Marjorie Courtenay-Latimer, curator of the East London Museum, examined a 1.5-meter fish taken in a trawl net. She sought help from J.L.B. Smith of Rhodes University, who replied from her drawing that it resembled forms long extinct; on seeing it in February 1939 he confirmed it as a coelacanth and named it Latimeria chalumnae after her and the mouth of the Chalumna River.

Smith searched for a second specimen until 1952, when Ahmadi Abdulla, a fisherman from the Comoro Islands, about 2,000 kilometers away, claimed the reward. Local fishers there already knew the fish as gombessa and caught two or three a year. In 1997 a second species, Latimeria menadoensis, was found in Indonesia.

There are not many coelacanths.

Some get caught by accident in fishing nets. Now there are laws to protect them.

The West Indian Ocean coelacanth is Critically Endangered, the most serious level of risk for animals still living in the wild. Nobody knows exactly how many there are, but one island, Grande Comore, may have only 300 to 400.

Coelacanths are not good to eat, but they are sometimes caught by accident in deep nets. In the past some were caught on purpose for scientists, museums and aquariums. Today international law protects them from being bought and sold.

The IUCN lists Latimeria chalumnae as Critically Endangered (A2bcd), but the assessment dates from 2000 and is flagged as needing an update; it predates the Tanzanian and recent South African records. Fishing is the listed threat. Both coelacanth species are protected from international trade under CITES.

Historically, coelacanths had little value as food and were released, but once scientists wanted them, rewards and later a black market encouraged targeted catches; Smith himself warned against rewarding captures. Off Tanzania, a burst of catches in deep-set nets after 2003 raised concern that fishing might threaten the population, and Tanzanian authorities planned studies of its size and status to guide conservation (Benno and colleagues, 2006).