THE ANIMAL FILES

Frilled shark

Chlamydoselachus anguineus

An eel-like outline belongs to a shark.

The frilled shark combines a long body with six pairs of gill slits and rows of slender, multi-pointed teeth. Squid remains provide evidence of feeding, while its liver contributes to buoyancy. Some proposed hunting behaviours remain interpretations rather than direct observations.[1]

Follow the evidence ↓
Frilled shark
Image: This illustration was made by Citron You must credit this : Citron / CC-BY-SA-3.0 · Commons · CC BY-SA 3.0
The frilled collar
The first gill slits meet beneath the throat.[1][2]
Teeth and squid
Teeth have long pointed cusps.[1]
Buoyancy without a gas bladder
Low-density liver lipids contribute buoyancy.[1]

The frilled collar

Six pairs of gill slits line the throat region, with the first pair forming a collar. Their fringed edges give the shark its common name, while a small dorsal fin sits far back on the elongated body.[1][2]

Teeth and squid

Slender, recurved teeth can snag soft prey. Squid beaks found in digestive remains support the importance of cephalopods in the diet; bony fish and smaller sharks are also recorded. The beaks are evidence from meals, not recordings of the strike itself.[1]

Buoyancy without a gas bladder

A large lipid-filled liver contributes to buoyancy. Lateral-line receptors separately detect movement, vibration and pressure changes in surrounding water.[1]

A COMMON MIX-UP

Does its eel-like body place it among eels?

No. Its NCBI lineage is that of a cartilaginous shark, not a bony eel.[2]

TRY A LITTLE REASONING

What can squid beaks reveal, and what can they not show?

Reveal the explanation

They support squid consumption but do not reveal the exact movements used to capture each squid.[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 — Frilled shark (cited revision)
  2. NCBI Taxonomy — Chlamydoselachus anguineus

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