“THE ADMIRABLE CHITON” (A DELPHI BEACH MYSTERY)
The beach at Delphi is good for combing. Most of Abaco’s beaches are too, for that matter. You can find Kasia’s beachcombing page HERE. Last month 2 guests, Linda and Jan, went exploring on the beach and returned with a handful of mystery items they had found under the clumps of seaweed. These were clearly neither complete nor broken shells, and even after some research in books and online I remained baffled. They were obviously parts of some water-based species… but what parts, anatomically speaking? And what species?
So I contacted Colin Redfern, Bahamian sea shell expert and author of a magisterial tome on the subject. His response was typically swift and definitive:
The ladies have found some beach-worn valves from the common Fuzzy chiton, which was so nicely photographed by Kasia on your April 12, 2012 entry – (the one that included fecal pellets) [See Header]. As you know, the meat from this species is eaten by Bahamians, who discard the unwanted shell. The individual plates then become separated by wave action and normal deterioration. Abaco has a pretty good selection of chiton species, and individual valves from some of the other species are sometimes found on beaches.
Chitons (pron. kytens) are marine molluscs with a great many species worldwide, from very small to quite large. Their shell comprises 8 interlocking and overlapping curved plates known as ‘valves’ that provide a flexible protection, and articulate as the creature moves. Chitons – at least some species – can even curl up into a protective ball. The plates are held together by a ‘girdle’ surrounding the animal.
Fossil records show that these primitive-looking animals derive from the Devonian period – or even Ordovician. They remind me of trilobites, even older creatures from the Cambrian period that used to fascinate me at school when I was small and paying attention. The name chiton derives from Latin word for mollusc, which itself comes from an older Greek word meaning a tunic. Which they in no way resemble.
After a chiton dies, the valves which make up the eight-part shell come apart because the girdle no longer holds them together and these the plates may wash up in beach drift, to be found by Linda and Jan. The individual shell plates are sometimes known as “butterfly shells” due to their shape.
A DOZEN CHITON FACT TO AMAZE YOUR FRIENDS WITH
- Chitons are also known as ‘sea cradles’ or ‘coat-of-mail shells
- Their shell consists of 8 plates / valves so flexible that they can even curl into a ball
- They move with a muscular ‘foot’, and use it to cling onto rocks like a limpet
- They have no definable head, no tail and no eyes, only ‘photoreceptor cell clusters’
- The mouth on on the underside of the chiton
- It contains a sort of tongue – a radula – with rows of teeth, each with 17 (why 17?)
- They use the radula to scrape the rock substrate for algae and similar
- A chiton’s digestive system produces neat little fecal packages like white pills
- Its anus is next to its foot, a design mercifully not found in humans
- I learn that chitons “lack a cerebral ganglion”. I think this means, no brain as such
- However they do have a primitive ‘homing’ ability too complex to summarise…
- Chitons are eaten by people mainly in the West Indies and the Philippines
WHAT? YOU CAN EAT THEM?**
If you are asking that question, you perhaps read right through the 12 facts to the very last one. If so, you deserve an answer and indeed a recipe for Chitons aka ‘Sea Cockroaches’. And who better to provide it than the brilliantly-named PSYKDELIASMITH Click the link to find out more.
**CAUTION As a couple of people have rightly pointed out (thanks Liann and Julias) since I posted this, not all chitons are edible. Some are poisonous. So before you think of a culinary chiton caper, best check that you have got an edible one
A chiton on the move, very slowly, and apparently halted by an encounter with a nerite
Colin Redfern kindly sent me a pdf of the chiton section of his book. Of the fuzzy chiton he writes: “Occurrence: Very common intertidally on rocky shorelines. Known locally as a Curb, with the meaty foot used as an alternative to conch in salads. Gutted specimens or disarticulated valves consequently common along shorelines.” Which is just where this post began.
And if you want to know about the title and its link to Peter Pan, click THE ADMIRABLE CRICHTON
POST SCRIPT This post has generated quite a lot of comment on Facebook. Here are a few, plus an amazing discovery in Hope Town