← Back to the archive★ Support my pages
DD-190NatureFiled Last updated

Largest Crabs on Earth!

Short answer: Spider crabs are crabs of the superfamily Majoidea, named for their long, thin legs. The Japanese spider crab (Macrocheira kaempferi) has the largest leg span of any arthropod, up to about 3.7 m.

Many spider crabs decorate their shells with sponges, algae and debris for camouflage. In southern Australia, giant spider crabs (Leptomithrax gaimardii) gather in huge aggregations of thousands each year to molt together, which researchers think protects them while their new shells harden. The footage shows spider crab aggregations and Japanese spider crabs, with the presenter.

VideoWrite-up3 sources
More like this★ Support my pagesCite this file

What should you know about Largest Crabs on Earth!?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Spider crabs belong to the Majoidea.

    DD-190-F01 · Write-up · Exhibit A (Majoidea)

  2. The Japanese spider crab spans up to about 3.7 m.

    DD-190-F02 · Write-up · Exhibit B (Largest span)

Video transcript: Largest Crabs on Earth!: Japanese Spider Crabs Can Span Nearly 4 m Leg to Leg

Spider Crabs members of the crustacean family are intriguing creatures known for their remarkable appearance in annual mass migrations Did you know they have a peculiar habit of forming large Aggregations during the mating season thousands of spider crabs gather together and migrate in a caravan across the ocean floor What adds to their allure is their distinctive appearance with long spindly legs resembling a spider providing them with excellent camouflage among underwater vegetation this behavior and unique morphology Demonstrates the fascinating adaptations that spider crabs have evolved to thrive in their marine environments. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 33.1s Reel ·

Video coming soonLargest Crabs on Earth! · Instagram Reel
Largest Crabs on Earth!: Japanese Spider Crabs Can Span Nearly 4 m Leg to Leg Instagram Reel · · 33.1s

The write-up

Japanese spider crabs can span nearly 4 m leg to leg. In Australia, thousands of spider crabs pile up each winter.

  1. Exhibit A

    Majoidea

    Spider crabs belong to the Majoidea.

  2. Exhibit B

    Largest span

    The Japanese spider crab spans up to about 3.7 m.

  3. Exhibit C

    Decorating

    Many decorate their shells for camouflage.

  4. Exhibit D

    Aggregations

    Australian giant spider crabs gather by the thousands.

  5. Exhibit E

    Molting together

    They gather to molt.

Questions people ask about Largest Crabs on Earth!

What are spider crabs named for?

Superfamily Majoidea.

Source: Write-up · Exhibit A (Majoidea) · Wikipedia: Spider crab

Which crab has the largest leg span?

Up to about 3.7 m.

Source: Write-up · Exhibit B (Largest span) · Wikipedia: Japanese spider crab

How do many spider crabs hide?

Sponges and algae.

Source: Write-up · Exhibit C (Decorating) · Wikipedia: Spider crab

Where do giant spider crabs aggregate?

By the thousands.

Source: Write-up · Exhibit D (Aggregations) · Wikipedia: Leptomithrax gaimardii

Why do they gather?

Safety in numbers.

Source: Write-up · Exhibit E (Molting together) · Wikipedia: Leptomithrax gaimardii

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What are spider crabs named for?

    1. Long, thin legs
    2. Webs
    3. Venom
    4. Eight eyes
    Show the answer

    Answer: A. Long, thin legs Superfamily Majoidea. Source: Write-up · Exhibit A (Majoidea) · Wikipedia: Spider crab

  2. Which crab has the largest leg span?

    1. Japanese spider crab
    2. Blue crab
    3. Hermit crab
    4. Fiddler crab
    Show the answer

    Answer: A. Japanese spider crab Up to about 3.7 m. Source: Write-up · Exhibit B (Largest span) · Wikipedia: Japanese spider crab

  3. How do many spider crabs hide?

    1. Decorating their shells
    2. Changing color instantly
    3. Burrowing
    4. Flying
    Show the answer

    Answer: A. Decorating their shells Sponges and algae. Source: Write-up · Exhibit C (Decorating) · Wikipedia: Spider crab

  4. Where do giant spider crabs aggregate?

    1. Southern Australia
    2. Iceland
    3. Kenya
    4. Peru
    Show the answer

    Answer: A. Southern Australia By the thousands. Source: Write-up · Exhibit D (Aggregations) · Wikipedia: Leptomithrax gaimardii

  5. Why do they gather?

    1. To molt together
    2. To hibernate
    3. To lay eggs on land
    4. To fight
    Show the answer

    Answer: A. To molt together Safety in numbers. Source: Write-up · Exhibit E (Molting together) · Wikipedia: Leptomithrax gaimardii

Cite this case file

Easterling, Marcus. "Largest Crabs on Earth!." The Detail Department (DetailEnjoyer), case file DD-190, last updated Jan 19, 2024. https://detailenjoyer.com/case/largest-crabs-on-earth/

Permalink: https://detailenjoyer.com/case/largest-crabs-on-earth/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-190-F01 → https://detailenjoyer.com/case/largest-crabs-on-earth/#DD-190-F01