“THE ADMIRABLE CHITON” (A DELPHI BEACH MYSTERY)


Fuzzy Chiton, Delphi, Abaco (Kasia Reid)

“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?

Fuzzy Chiton valves (segments), Delphi Beach, Abaco, Bahamas

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.
Fuzzy Chiton, wiki

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.

Acanthopleura_granulata_(West_Indian_fuzzy_chitons)_(San_Salvador_Island,_Bahamas) James St. John

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.

Fuzzy Chiton, Abaco (Kasia Reid)

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, onlyphotoreceptor 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

Chiton, Abaco 2 (Kasia Reid)

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

wp809b3177_06

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.

FUZZY CHITON scientific doc (Colin Redfern)

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
  • “Commonly know as a curb, they are edible (raw) you make a salad like you do with conch , delicious !!!” (Rosalie Pyfrom)
  • True some are poisonous, but your have to know which ones!! I was showed as a child which were good from bad!!” (Janice Carey Hall) 
  •  “Very delicious” (Cantrell Walker)
  • “Lets not forget the poisonous ones!” (Julias Sawyer)
  •  “Don’t mess wit my curbs, nom nom”  + “Definitely do NOT eat the very large ones with the bumpy rim”.(Liann Key Kaighin)
  • “Curb stew is a Bahamian food that has since the loyalist arrived” (Steve Roessler)
 Gary Richardson Jr.'s photo.

Then Gary Richardson Jr added a photo of what must be a pearl, found in a curb in Hope Town. 

 To which I replied “Well that’s a surprise! Interesting find. Did a bit of research. Apparently all shelled molluscs are capable of producing ‘pearls’ – though they have no value. So this must be a chiton pearl…”
Credits: Linda & Jan for their beachcombing finds; Colin Redfern for his ID & info enabling this post (and his continuing interest); Kasia Reid; Hans Hillewaert & James St John (wiki uploads)

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS


Sand Dollar Doves (Keith Salvesen) 6

Sand Dollar from Abaco containing 5 miniature white doves…

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS

Echinoderms (Gr. ‘Hedgehog Skin’) comprise a large variety of sea creatures characterised (mostly) by radial symmetry, often five-way. For Abaconians, the most frequently encountered are starfish, sea urchins, sand dollars and sea biscuits. I am going to look at two particular aspects of dollars and biscuits, conscious that my illustrative photos of white objects were stupidly taken against a white background.

DOLLAR DOVES

I’m sure all Bahamians know or are aware of at least one version of the famous ‘Sand Dollar’ poem, in which the various characteristics of the test (the skeleton of the creature) are given religious significance. One verse of the poem may be puzzling: “Now break the centre open And here you will release The five white doves awaiting To spread good will and peace”.

Recently, Senior Granddaughter (10 this week) was looking at some Abaco sand dollars in her unfeasibly huge collection of shells. She picked one up, shook it and it rattled. She said a friend at school had told her that a rattling sand dollar has ‘doves’ inside it, and asked if we could break it open and see. I’ve learnt that it is useless to argue with her – she has the tenacity of a trial lawyer – so we did. This is what we found.

Sand Dollar with a spiky interior like a white cave with stalagmites and stalagtitesSand Dollar Doves (Keith Salvesen) 4

Five white doves (in fact, the separated parts of the creature’s feeding apparatus)Sand Dollar Doves (Keith Salvesen) 1

Two broken pieces showing where the doves are centrally locatedSand Dollar Doves (Keith Salvesen) 5

A single dove (best viewed the other way up for full-on doveliness)Sand Dollar Doves (Keith Salvesen) 3

The photo below, from Pinterest, shows the ‘mouth’ with its 5 dove-parts intact, an arrangement called ‘Aristotle’s Lantern’.

Sand Dollar : Aristotle's Lantern : Doves (Pinterest)

PETRIFIED BISCUITS

In common parlance ‘petrified’ is an extreme version of ‘terrified’. Literally, it means ‘turned to stone’ (L. Petrus, a rock). It is descriptive of a state of fossilisation, where an animal skeleton or dead wood or plant matter turns over aeons into stone. Undaunted by her Doves discovery, SG (a most inquisitive girl) also discovered a box containing random stones and fossils. She found these two items:

Fossilised sea biscuitsPetrified Sea Biscuit (Keith Salvesen) 1

A closer look at the pair of rocksPetrified Sea Biscuit (Keith Salvesen) 5 Petrified Sea Biscuit (Keith Salvesen) 4

The undersides of the fossils above – looking like stones but with some tell-tale small holesPetrified Sea Biscuit (Keith Salvesen) 2 Petrified Sea Biscuit (Keith Salvesen) 3

A close-up of the pale biscuitPetrified Sea Biscuit (Keith Salvesen) 6

Sea biscuits as everyone knows them, on the beach at Delphi – skeletons but not yet fossilsSea Biscuits, Delphi, Abaco (Clare Latimer) copy

A ‘modern’ sea biscuit in close-upSea Biscuit, Abaco (Rhonda Pearce) copy

FUN FACT

Florida has an unofficial but proposed State Fossil, the ‘Sea Biscuit (Eocene Age)’. I didn’t know it before, but it turns out that around 40 States have State Fossils. Whatever next? State Bacteria?

SO HOW OLD MIGHT A PETRIFIED BISCUIT BE?

The fossil biscuits I have looked at, from Florida to Madagascar, are said to come from three specific historic epochs – from the oldest, Jurassic (145m – 201m years ago),  to Eocene (34m – 56m) and Pleistocene (0.01m – 2.6m). 

HOW DOES THAT HELP ANYBODY? BE MORE PRECISE

By all means. Here is an excellent Geochart that gives an idea of the time span. A Jurassic sea biscuit would be more than 145m years old. So maybe the next plan should be to take the 2 petrified sea biscuits plus SG to a museum to see if we can get an idea of their age…geotimescale

All photos ‘in-house’ except the Delphi biscuits, Clare Latimer & the single biscuit Rhonda Pearce; Geochart to be credited asap, mislaid the source…

ROLLING HARBOUR, ABACO: LIFE’S A BEACH & THEN SOME…


Rolling Harbour Beach, Abaco1b

ROLLING HARBOUR, ABACO: LIFE’S A BEACH & THEN SOME…

Rolling Harbour (the geographical feature) is a gently curving one-mile white sand bay presided over by the Delphi Club, which sits on a 50 foot cliff behind the beach. There are rocks at either end, fish in the sea (including bonefish and, in the right conditions, permit), birds on the shore and shells on the sand. And that’s it… 

Rolling Harbour Beach, Abaco2bRolling Harbour Beach, Abaco3bRolling Harbour Beach, Abaco4bRolling Harbour Beach, Abaco5bRolling Harbour Beach, Abaco6bRolling Harbour Beach, Abaco7bRolling Harbour Beach, Abaco8b

And if anyone can explain the strange ribbed sky effect that seems to have appeared from nowhere when I posted these photos that I took last year (300dpi), then I’d be very grateful…

BIRDS OF SAN SALVADOR, BAHAMAS: BOOK REVIEW


Birds of San Salvador (cover) JPG

THE BIRDS OF SAN SALVADOR, BAHAMAS

  • Authors: R. Hays Cummins, Mark R. Boardman, Mark L. McPhail
  • Published 1 Jan 2013, 132pp with 400+ images covering 54 species
  • Available spiral bound for $29.95 on Am@zon; and a steal at $3.16 for Kindle (£5.99 in the UK)
  • STOP PRESS Also available on iTunes for iPhone / iPad, where I imagine it looks great. Once downloaded, author Hays says it can be viewed on a Mac, certainly if you have the latest OS X Mavericks. UK price: a very modest £1.99 (= $3.30)

Within a couple of weeks of the decision to use Tom Sheley’s wonderful Bahama Woodstar as the ‘cover bird’ for “THE BIRDS OF ABACO”, another Bahamas bird book was announced. The same colourful and enchanting endemic bird had also commended itself to the authors for their cover. I wrote to Hays Cummins at once to check whether he would mind another Bahamas bird book encroaching on the territory, especially one using the same cover bird into the bargain. He very charmingly said it would be fine and declared his support for our (luckily) rather different project.

It’s been a while since I added to the section BOOKS, but I thought I’d mention this one for two reasons. First, it is described as ‘A Photo Essay of Common Birds’, which in practical terms means that most if not all of the species featured will be common to the northern Bahamas and therefore familiar on Abaco. Secondly, I very much like the format of the book: there are clear photos; and all necessary general information including notes on individual characteristics and similar species is presented in an easily assimilable way. Were the Delphi book not designed to be the 2 kg bird-showcasing non-field guide doorstop it is, the San Salvador book is one I should liked to have produced! Birds of San Salvador (sample page 1) Birds of San Salvador (sample page 2) DESCRIPTION “This enchanting book addresses a need for an important audience, the budding naturalist, which many of our students are. Without fanfare and pomposity, the book presents beautiful and inspiring photos and lively discussion, but does not indulge in the details of the accomplished birder. The authors present information about the natural history of birds on San Salvador, Bahamas, not through the eyes of a professional or advanced birder, but through the eyes and photographic lenses of inquiring educators and naturalists. This book will help capture and catalyze the interests of aspiring birders and will be an asset for introductions to the birds of the Bahamas and neighboring Caribbean. Over 400 images, representing 54 species, are all original and include a variety of behaviors and highlight recognition characteristics. The authors’ aesthetic photography, printed on high quality paper, will help reinforce identification and enjoyment. Birds are organized by habitat (Coastal, Interior, and Lakes & Ponds), not by taxonomic affinities. A taxonomic index is included.” 

I’m pleased to see the decision to depart from the usual taxonomic ordering of species, though I recognise that for a serious field guide that tradition is pretty much sacrosanct. We played around with categories and sub-categories a bit (sea birds, water birds, land birds; big, medium, small; cute, splendid, dull, plug-ugly) before settling on Peter Mantle’s excellent idea of straight alphabetical organisation. For a mainly photographic book this gives an element of surprise to turning the pages, and avoids  e.g. 37 pages of warblers species, mostly yellow, all huddled together.  Birds of San Salvador (sample page 4) Birds of San Salvador (sample page 5) I notice that there is a single Amazon review, a good one, that says “This guide to one of the lesser known islands in the Bahamas is a nice one. While not exhaustive, it covers most of the species likely to be seen on San Salvador. The style is unorthodox for a field guide (elements of humor, gives brief description of species, but no real key field marks), the descriptions, locations on the island, and behaviors make this guide useful for those visiting San Salvador. The photographs are excellent.” Birds of San Salvador (sample page 3)For anyone interested in a useful reference guide to the common birds of Abaco, and in possession of a Kindle, this book is easily worth getting electronically.  ‘To be brutally honest’ (™ Sandy Walker), I’d like in due course to produce a small book very like this for Abaco, but it would obviously be naked plagiarism to do that, so of course I won’t. Still, all the same…

SMALL SHELLS FROM CASUARINA, ABACO


Abaco Shell 3b

SMALL SHELLS FROM CASUARINA, ABACO

Abaco Shell 1Abaco Shell 4Abaco Shell 2Abaco Shell 5Abaco Shell 6

The shell species below (also in the header picture) is an olive. It turns out to have potential to star in a small maritime horror movie. Capt Rick Guest, who kindly keeps an eye on my shell and other sea-related posts, writes “Interestingly, the previous occupant of the first and last shell pictured here is a major predator of the other Bivalve shells shown. The Olive shell hides under the sand by day, then emerges at night to feast upon small Bivalves, and any other available prey. One can often trace the nocturnal trails of this Olive shell in sand on calm mornings with mask and snorkel, and thrust a hand under a trails end for this fellow. When kept in an aquarium, they will consume any meat offered.” “Olive and Let Die”, maybe?Abaco Shell 3aAbaco Shell 7

SHORE THINGS: BEACHCOMBING ON A PRISTINE ABACO BEACH


Shore Things 16

SHORE THINGS: BEACHCOMBING ON A PRISTINE ABACO BEACH

The Abaco bay known as Rolling Harbour is a 3/4 mile curve of white sand beach, protected by an off-shore reef. The beach is pristine. Or it would be but for two factors. One is the seaweed that arrives when the wind is from the east – natural and biodegradable detritus. It provides food and camouflage for many species of shorebird – plover and sandpipers of all varieties from large to least. The second – far less easily dealt with – is the inevitable plastic junk washed up on every tide. This has to be collected up and ‘binned’, a never-ending cycle of plastic trash disposal. Except for the ATLAS V SPACE-ROCKET FAIRING found on the beach, that came from the Mars ‘Curiosity’ launch. Sandy's Mystery Object

We kept is as a… curiosity, until it was eventually removed by the men in black…

Shore Things 14I’d intended to have a ‘plastic beach trash’, Atlantic-gyre-rage rant, with angry / sad photos to match. Instead, I decided to illustrate a more positive side to beach life – things you may discover when you take a closer look at the sand under your feet. Like the coconut above. Many of these photos were taken by our friend Clare Latimer (to whom thanks for use permission); some by me.

Shore Things 13A LONE FLOWERShore Things 17SEA STAR (DEFUNCT), WITH CRAB TRACKSShore Things 21SEA FAN (GORGONIAN)Shore Things 15WASHED-UP BOTTLE (PROBABLY NOT RUM)Shore Things 12

SEA BISCUITSShore Things 9

Thanks to Capt Rick Guest, who has contributed an interesting comment regarding the sea biscuit with a hole in it. He writes “the (Meoma) Sea Biscuit w/ the hole in it was dined upon by a Helmet Conch. The Cassis madagascariensis, or C.tuberosa drills the hole w/ its conveyer-belt-like radula teeth w/ some help from its acidic, saliva. Probably 98% of all symetrical holes in marine invertebrates are of this nature. Murex, Naticas, Helmets, and many Cephalapods (via a Stylet), are the usual B&E suspects. The Cone shells utilize a modified radula in the form of a harpoon which is attached to a venom tube.” For more on the vicious cone shell, and other creatures to avoid, click HERE

DRIFTWOOD. IT’S LIKE… OH, USE YOUR IMAGINATIONShore Things 5A WILSON’S PLOVER NESTShore Things 11HORSESHOE CRAB (LIMULUS)Shore Things 4SCULPTURE? AN EMBRYONIC SHELTER? Shore Things 3LARGE BIRD FOOTPRINTSShore Things 18MORE BIRD PRINTS AND CRAB TRACKSShore Things 19 CRABUS CUTICUSShore Things 6CONCH SHELLS & OTHER BEACH TREASURESShore Things 8Shore Things 20CRAB HOLE & TRACKSShore Things 22SOME IDIOT’S LEFT HIS… OH! IT’S MINEShore Things 7

‘BEAUTY & THE BEACH’: A CLOSE LOOK AT ABACO SHELLS


Abaco seashell 11

‘BEAUTY & THE BEACH’: A CLOSE LOOK AT SOME ABACO SHELLS

Abaco seashell 10Abaco seashell 7bAbaco seashell 6bAbaco seashell 3bAbaco seashell 2bAbaco seashell 1bAbaco seashell 4bAbaco Shells 12bAbaco seashell 5bAnd to end with, not a shell but a somewhat unattractive head shot…Abaco seashell 9b

BEAUTY PARADE

Abaco seashell 7aAbaco seashell 6aAbaco seashell 3aAbaco seashell 4aAbaco Shells 12 aAbaco seashell 5a

UGLY BUG BALL…

Can anyone ID this? It’s not what I thought… *later* yes they can! See comments for the debateAbaco seashell 9b

Skull 2

All shells – & the spider crab carapace – collected from the beach at Casuarina