THE ANIMAL FILES

Atlantic blue crab

Callinectes sapidus

An estuary resident with an ocean-going beginning.

The Atlantic blue crab connects planktonic early stages with an estuarine adult life.[1]

Follow the evidence ↓
Atlantic blue crab
Image: NOAA · Commons · Public domain
Life across the estuary
Larvae and adults use different waters[1]
A new shell for growth
The exoskeleton is shed and replaced[1]
An adaptable menu
Plants, animals and carrion[1]

Life across the estuary

Eggs hatch in relatively salty coastal waters, and early larvae drift near the surface. Later stages move toward estuaries, where chemical cues accompany the transition to juveniles.[1]

A new shell for growth

Growth proceeds through moulting: the old covering is shed and a larger one becomes exposed and hardens. Temperature and food availability influence the interval between moults.[1]

An adaptable menu

Blue crabs consume both animal and plant material, including small bottom-dwelling organisms and carrion. They can also be prey for fishes and rays.[1]

A COMMON MIX-UP

Does “blue” describe every visible surface?

No. Claw colours and abdominal shape differ with sex and maturity. The common name does not replace a description of the whole animal.[1]

TRY A LITTLE REASONING

Why can two similar-sized crabs be different ages?

Reveal the explanation

Food and temperature affect moulting and growth. A size measurement records the outcome of development under those conditions, not a universal age stamp.[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 — Atlantic blue crab (cited revision)
  2. NCBI Taxonomy — Callinectes sapidus

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