Isla Mujeres Mystery ~ Lynda L. Lock

2005 the first Hermit Crab that we had ever seen

 One beautiful star-lit evening we were enjoying a glass of wine on the beach with family members. I heard a strangled yelp from my spouse.  Something large and round – about the size of my fist – was cruising along the sand.  When exposed with the camera flash it turned out to be a large hermit crab, out looking for a tasty late night dinner.   Pretty cool creature. And so began my fascination with hermit crabs.

It’s a fascination that has become an obsession, an obsession sparked by a casual comment of a vacationing guest at Villa Mar Caribe.  Apparently once the miniscule hermit crab babies leave the ocean to live on land they are constantly on the lookout for new shells.  They are unable grow their own shells, and must find progressively larger shells that have been discarded or washed up on the beach.  

Water, some cat food as a treat – and they will come!

She suggested that I leave a variety of shells in one location for the crabs to chose from, and they might switch for something bigger or better.  We did that and very shortly discovered that the word was out in the hermit crab world, finding a dozen or so crabs checking out the shells on a nightly basis.  From then on every shelling foray onto the beach was based on finding only perfect shells for hermit crabs, adding them to the Crab-i-tat.  (Yes, embarrassingly enough I have named the location where I stockpile shells, drinking water and occasionally food for the hermit crabs.)
The best shells – this batch marked with pale pink nail polish
The best shells for crab houses are the ones that hermit crabs will have a hard time resisting.  The ‘crème de la crème’ of hermit crab shells have a smooth mother-of-pearl interior, nice heft, perfect coil to the right (who knew a hermit crab could tell left from right?)  The mother-of-pearl is easy on the soft abdominal skin, while the thickness of the shell insulates the crab from predators and temperature extremes.  It is important that the shells are intact, no holes, as the crab needs to carry water inside the shell to maintain its health.

Worn out, broken, holed, plastic bottle caps – trade-ins.

The worst shells are ones that a crab will cast off, in a heartbeat. These shells are uncomfortable because they are thin-walled and do not offer much protection from the elements, or perhaps the coil of the shell is awkward for the crab to maneuver, or has a rough interior, or there are holes in the shell. I have had a variety of weird things left behind as a hermit crab castoff – the funniest being a broken bottle neck with a metal screw-on cap still attached. In the crab’s world it’s a bit like trading in a rusty broken-down camper-van for the new top of the line bus-style RV.
Went walk-about from our house to our friends, 10 lots north
After a few months of supplying crab houses, I started marking the shells that I supplied with red, purple, blue or orange nail polish so that I could keep track of “my” hermit crabs.  We have had various neighbours, including friends who live 10 lots north of our house, tell us that they saw one of the marked large hermit crabs on their property.  Ten lots may not sound like much, but when you are the size of an orange – crawling that distance with your house on your back is a pretty big adventure.
Two hermit crabs stealing a quick snack from our cats’ kibble
Fortunately the cats don’t bother the hermit crabs because they are no fun to harass – merely snapping back into their shells with a loud clack when poked by a furry paw. My crazy little Mexican cat, Chica, delights in slapping the crabs (like mini hockey pucks) along the patio in the evenings. Occasionally a crab or two will wander into our house looking for cat food or a refreshing bath in the cats’ water dish.  This activity does not sit well with our two spoiled felines.
The embarrassing part of this whole fascination is that I can no longer keep up with shells from beach combing.  We have in excess of 300 crabs visiting the Crab-a-tat on a regular basis.  I now have a local shell supplier who makes house calls once a month to restock my supplies, and various friends have dropped off donations of shells that they have found!
It’s a little out of hand, but what the heck it’s a harmless obsession.


7 Replies to “What the heck is that?”

  1. Was that 07 when our guest started the “Used Shell Lot…Trade Ins Welcomed”? One of these days we gotta get Bruce to set up a webcam..tho I guess it'd need night vision? Fascinating and creepy. My favorite tale is when ya bought shells that turned out to be from the the other hemisphere that spiraled the opposite way, & the crabs did NOT approve. 2nd fav is when ya explained how they get in a row and as the bigger guy in front exchanges his shell, the dude behind him holds on waiting to upgrade into the rejected shell in front of him. The mysterious part is that ya always end up with fewer shells…there must be a lotta naked crabs in that empty lot. When she puts out a new batch, word gets out within half an hour the joint is jumping! Apparently the crabs have a “coco line” too.


  2. What an awesome story. I read it to my granddaughter and of course she now thinks I should haul all those shells I have hauled home for her over the years back to Isla….luckily most of them are not perfect for crab houses…


  3. Hi Becky – I would love to see your hermit crab video! Too funny.

    And Ronda, I finally figured out why we get back less shells than we put out. If you check the beach in the morning there are teeny tiny little shells, so small they are almost invisible – which means the shell trading went on all night long from biggest to tiny until there was nothing left! You are right creepy but fun.

    Catrina – I love you screen name. Fits perfectly with my Day of the Dead blog. I'm glad your granddaughter enjoyed the hermit crab story.


  4. Such interesting stuff–I had no idea hermit crabs were so picky…
    (Jim Conrad, who writes 'Naturalist Newsletter, did a story in August on hermit crabs also.) -kris


  5. Hermit crabs are picky little brats, but then everyone likes a clean, comfy house – or since the house moves with them a clean comfy motorhome.


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