THE ANIMAL FILES

West Indian Ocean coelacanth

Latimeria chalumnae

A blue fish whose daylight shelter is not its night-time dining room.

The West Indian Ocean coelacanth is a living animal with a daily routine, not just a famous name in evolutionary history. It rests in underwater caves and feeds in the surrounding area at night. Its large eyes, spotted blue body and unusual feeding observations connect anatomy with the dim habitats it uses.[1]

Follow the evidence ↓
West Indian Ocean coelacanth
Image: Bruce A.S. Henderson · Commons · CC BY 4.0
Body colour
Deep blue with pale spots[1]
Daytime location
Underwater caves[1]
Known food
Several kinds of fish[1]

Seeing where light is limited

Large eyes and numerous rod cells are features associated with vision in limited light. A reflective layer also sends light back through the retina.[1]

Daytime caves, night-time feeding grounds

Individuals spend the day in underwater lava caves and use nearby feeding areas at night. The shelter and the place where food is obtained are therefore not identical.[1]

An unusual posture deserves careful wording

Some coelacanths have been observed in head-down positions while feeding near crevices. Their skull includes an intracranial joint, whose exact contribution to feeding is not fully understood.[1]

A COMMON MIX-UP

Does a cave observation show its whole routine?

No. Cave use during the day and feeding outside at night describe different activities. The animal’s behaviour needs to be considered across time as well as across locations, rather than inferred from one still photograph.[1]

TRY A LITTLE REASONING

Why separate a feeding observation from a mechanical explanation?

Reveal the explanation

Head-down feeding has been observed, but the skull joint’s role remains incompletely understood. Describing the posture does not by itself establish how that joint contributes to capturing food.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — West Indian Ocean coelacanth (fixed revision; adapted and translated)
  2. NCBI Taxonomy — Latimeria chalumnae (identity and classification)

Last fact check:

One discovery leads to another

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