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iLabs: Our Newest Addition — CRAYFISH!!! And a Visitor Question about them

August 13, 2012

We have new creatures in the Micro World iLab!!! Crayfish!!  We had wanted to add them to our pond tank, part of the whole “cycle of life” thing, but on the advice of our aquatics professionals at the museum, we opted to have them in a separate tank. (Apparently the crayfish would tear up the tank’s plants, eat the snails, dig up the gravel and eat our fish, so….)

However, to come back to things, do come visit and check out the crayfish. Our aquatics people did a beautiful job setting the tank up for us! 🙂 Kudos to them.

And of course, the crayfish seem eager to put on a visual display for our visitors as well. We had them a few days and already, they molted!!!

image of a crayfish molt

Here is the molted shell that the crayfish will eventually eat, to recapture the calcium and other nutrients it has.

molted crayfish hiding in bushes as it is vulnerable to predators

Here is our “molted” crayfish, hiding in the plants. Its shell is very soft right now, thus rendering the crayfish vulnerable.

This timely molting today yielded our newest Visitor Question: How often do crayfish molt?

One website says 6-10 times the first year, less the next year, and their life span is short, less than 2 years.

Yahoo Answers website adds: “it depends on their age. i got my latest crawfish at the beginning of may and he just molted today. if the are very young they can molt once every few weeks. but as they get older they molt less often, usually only a few times each year”

And the Fish Site says it takes approximately 11 molts to reach maturity. After that they molt much less often.

This matches my experience with raising fiddler crabs — the younger they were, the more frequently they molted.

If you are interested in raising crayfish, here are some resources:

And do come see our new additions to the Micro World iLab!  They are fascinating to watch.

3 Comments leave one →
  1. August 13, 2012 2:28 pm

    Reblogged this on NC Museum of Natural Sciences Blogs and commented:

    By Deb Bailey

  2. Jess Beasley permalink
    August 16, 2012 10:52 am

    I just remembered a really cool conversation I had with Dr. Bill Kier from UNC about newly molted arthropods. Ordinarily their locomotion is driven by muscles pulling on the inside of their exoskeletons — but when an arthropod has just molted, the exoskeleton is too soft for that to work. However, they can still skuttle if they need to! His research showed that newly-molted crabs actually use a hydrostatic skeleton temporarily. (Other familiar examples of critters with hydrostatic skeletons are starfish and earthworms)

    Here’s a link to the paper:

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