THE ANIMAL FILES

Giant oceanic manta ray

Mobula birostris

The curled head fins can unfold to guide food-bearing water inward.

The giant oceanic manta ray has broad triangular pectoral fins and paired head fins beside a forward-facing mouth. Dark markings on the underside can help researchers recognise individuals across repeated sightings.[1]

Follow the evidence ↓
Giant oceanic manta ray
Image: jon hanson from london, UK · Commons · CC BY-SA 2.0
Head fins
Can roll up or unfold[1]
Feeding
Filters food from incoming water[1]
Identification
Underside patterns can distinguish individuals[1]

A funnel at the front

During feeding, the head fins unfold to guide water toward the mouth. Food particles are separated at filtering structures associated with the gills. Their position helps explain how a wide swimming animal channels a meal inward.[1]

A photograph can identify an individual

The pale underside often has dark spots and patches. Comparing their arrangement across images can connect separate encounters to the same animal. Body size alone is less helpful when young oceanic and reef mantas overlap in size.[1]

Cleaning visits have another purpose

At reef cleaning stations the manta can remain almost stationary while small fishes remove external material and parasites. A gathering near a reef may therefore involve body maintenance as well as feeding.[1]

A COMMON MIX-UP

Does a larger-looking ray always prove the oceanic species?

No. Age affects size, and young animals can overlap the size of reef mantas. Pattern and structural features also matter.[1]

TRY A LITTLE REASONING

Why photograph the same part of the underside each time?

Reveal the explanation

A consistent view makes the arrangement of individual markings comparable across encounters.[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 — Giant oceanic manta ray (fixed revision; adapted and translated)
  2. NCBI Taxonomy — Mobula birostris (identity and classification)

Last fact check:

One discovery leads to another

Southern stingrayEyes look upward while water enters through openings behind them.Hypanus americanus ↗Spiny dogfishA shark’s spines are not its teeth.Squalus acanthias ↗Blue sharkBlue above, pale below: an ocean swimmer has more than one colour.Prionace glauca ↗