Skip to content
Contact Us
The Crab Street Journal
The Crab Street Journal

Where hermit crab addicts go!

Primary Navigation Menu
Menu
  • Community
    • Blog Posts
      • General
      • ArtWork
      • Crabitat
      • Contest Voting
      • FAQ
      • Noteworthy Crabbers
    • Chewin’ the Choya (Forums)
      • Contest Entry Forum
    • Contest Rules
      • Hermit Crab Pumpkin Carving Contest
      • It’s the Great Pumpkin, Hermit Crab!
    • Testimonials
  • Resources
    • Hermit Crab Care 101
    • Caresheets
    • Hermit Crab Emergency Help
    • Hermit Crab Adoption Program
    • Hermit Crab Food Shop
    • Advocacy and Outreach
      • Say NO to Painted Shells
      • Animal Cruelty Laws
      • Pet Store Report Form
      • Pet Store Reports
    • Crabitat
    • FAQ
    • Food and Nutrition
      • Recipe Book for Hermit Crabs
        • Hermit Crab Recipe Submission Form
    • Biology
      • Hermit Crab Species
    • Hermit Crab Shops Directory
    • Hermit Crab Downloadable Files
    • Media Kit
  • About us
  • Milo the Hermit Crab – Daniel Kaye
  • Support CSJ!
    • Hermit Crab Clothing and Goodies
    • Donate-Paypal
    • Shop Our Suggested Items on Amazon
  • Affiliate Disclosure

Coenobita Pereiopods

In hermit crabs, the fourth and particularly the fifth pereopods are reduced, usually remaining within the confines of the gastropod shell and hence are not used for walking. These appendages do however becoming important when the hermit crab attempts to right itself, providing anchorage within the shell. Further, the fifth pereopod has become specialised as a gill cleaning appendage, often resting within the gill chamber (Bauer 1981). On the abdomen only the left pleopods are retained (Poore 2004).[1]

Photo credit - Amber Miner
Photo credit – Amber Miner
Photo credit - Amber Miner
Photo credit – Amber Miner
Photo credit - Amber Miner
Photo credit – Amber Miner
Photo credit - Amber Miner
Photo credit – Amber Miner
Photo credit - Amber Miner
Photo credit – Amber Miner
Photo credit - Amber Miner
Photo credit – Amber Miner
Photo Credit: Lisa Dawson
Photo Credit: Lisa Dawson
Photo Credit: Marnel Rodriguez
Photo Credit: Marnel Rodriguez
Photo Credit: Marnel Rodriguez
Photo Credit: Marnel Rodriguez
Photo Credit: Marnel Rodriguez
Photo Credit: Marnel Rodriguez
Photo Credit: Vanessa Pike Russell
Photo Credit: Vanessa Pike Russell
2015-10-04 12.02.30
Coenobita leg tips
Coenobita leg tips
Coenobita shield
Coenobita shield and pereiopods
Pre molt water sac
Pre molt water sac
Coenobita perlatus female
Coenobita perlatus female
Coenobita brevimanus male
Coenobita clypeatus male
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomen and abdominal appendages
Coenobita abdomenal appendages
Coenobita abdominal appendages
C. perlatus Photo Credit - Mary Milhorn
C. perlatus Photo Credit – Mary Milhorn
Coenobita pereiopods - Photo credit - Mary Milhorn
Coenobita male – Photo credit – Mary Milhorn
Coenobita pereiopods - Photo credit - Mary Milhorn
Coenobita pereiopods – Photo credit – Mary Milhorn
Coenobita pereiopods - Photo credit - Mary Milhorn
Coenobita female – Photo credit – Mary Milhorn

Hermit crabs used specialized setae on the their maixillipedes and fifth pereiopods for most grooming but used the unmodified first, second, and third periopods as well. Most brachyuran grooming was performed with modified setae on the the third maxillipedal palps and eipods, with a row of simple setae on each chelipede merus, and with the chelipede fingers.

The third maxillipedes and fifth pereiopods performed the majority of movements, including all of the more complex actions, and were suprisingly dexterous. Coenobita clypeatus devoted most of it’s grooming energy on the eyes and anntennules and did so with the mesial surfaces of the dactylus, propodus, carpus, and distal merus of the third maxillipedal endopods.

The three pairs of walking legs (chelipedes included) groomed themselves by scrubbing against each other in various combinations of two or three appendages. In addition, the fingers of the minor chelipede picked at the surface of the major chelipede. The chelate fifth pereiopods were quite flexible and extended as far forward as the chelipedes. The fifth pereiopods also groomed most of the central and posterior carapace, including the branchial chamber, and much of the abdomen. The fifth peeriopods groomed much of the shell’s interior, particularly the columella and innner and outer lips, as well as the exterior lips.These appendages did not function exclusively as grooming organs, as they also use their laterally situated gripping scales to brace the body against the shell (Johnson 1965, Vuillemin 1970).

After every few grooming acts, the fifth pereiopods moved anteriorly, in unison. to meet the two third maxillipedes, which were extended posteriorly beneath the body. The plumodenticulate and serrate setai of the posterior appendages were then scrubbed by the maxillipedes. The third maxillipedes, in turn, were scrubbed against each other and/or against the second maxillipedes after a grooming bout. The interior mouthparts had a self-cleaning function as well.

Thus, the maxillipedes groomed the anterior portion of the body (especially the sensory structures), the walking legs groomed each other, and the fifth pereiopods scrubbed the most posterior areas. Two movements were, at times, performed simulanteously, e.g., mutual leg scrubs and anntennule grooming. Although grooming may occur at any time, it was most frequentl and intense immediately after a ran and was often performed in standing water if it was available. Water is clearly an important debris-flushing medium. The grooming setae, parrticuarly the serrate setae, may also serve in a sensory capacity (Derby 1982).

Foam bathing, in which bubbles produced by the mouthparts disperse fluid about the body, occurred in partially submerged or emergent crabs. This action has been variously interpreted as a method of thermoregulation, pheromone distribution, water reserve aeration, or cleansing.(Altevogt 1968, Wright 1966, Lindberg 1980, Jacoby 1981, Schone & Schone 1963, Brownscombe 1965). [2]

Pereiopods are primarily walking legs and are also used for gathering food. Those pereiopods which are armed with a claw (chela) may be referred to as chelipeds. The moveable fingers of a claw are known as dactyls. The pereiopods bear the sexual organs (gonopores), which are the third pereiopod in the female and the fifth pereiopod in the male.

Anatomy of hermit crab leg "pereiopod"
Anatomy of hermit crab leg “pereiopod”

Land hermit crabs are able to regenerate lost appendages with molt.

Coenobita gel limb
Coenobita gel limb
Coenobita gel limb
Coenobita gel limb

We are building image galleries of specific body parts. If you have high resolution, clear photos that you would like to donate to this project please contact us via email: crabstreetjournal at gmail dot com


Overview of the anatomy of a land hermit crab (Coenobita)

Photo Credits:

Amber Miner

Lisa Dawson

Marnel Rodriguez

Vanessa Pike-Russell

Stacy Griffith

References

  1. Dardanus megistos by Storm Martin 2012
  2. Grooming structure and function in some terrestrial Crustacea

Share this:

  • Twitter
  • Facebook

Like this:

Like Loading...

Related

2015-09-27
In: General
Tagged: coenobita, hermit crab, hermit crab care, legs, limbs, pereiopods, walking
Previous Post: Hermit crab parasites
Next Post: Hermit crab grooming

Meta

  • Register
  • Log in
  • Entries feed
  • Comments feed
  • WordPress.org
Log In

Or Login with your social media account:

Other Hermit Crab Websites

Land Hermit Crab Owners Society (our parent org)
Land Hermit Crab Species
Stacy's hermit crab blog Breeding Hermit Crabs

Products We Recommend

Proud Member

The Crustacean Society
The Crustacean Society

The Crab Street Journal © 2001-2023

The CSJ Market will be closed June 10-12, 2023 for a show in Columbia MO. Dismiss

 

Loading Comments...
 

You must be logged in to post a comment.

    %d bloggers like this: