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

CONCH SHELLS & CONCHUPISCENCE ON ABACO


Conchs at Sandy Point a1

CONCH SHELLS & CONCHUPISCENCE ON ABACO

Most conchs encountered in daily life are lying peacefully on the beach; or are artfully displayed; or are found in conch heaps (often in the vicinity of restaurants) like the ones below at Sandy Point. Conchs at Sandy Point Abaco 2Conchs at Sandy Point Abaco 4

These shells at Sandy Point are so plentiful that they form a small spit of ‘land’ into the seaConch at Sandy Point (Clare)

An attractive display of conch shells in Marsh HarbourConchs Marsh Harbour Abaco

A less formal arrangement along the jetty at Man o’ War Cay (after a storm)Conch Man 'o War Cay jetty Abaco

It’s easy to forget that these shells are more than just a garden adornment, or pretty containers for a ubiquitous Caribbean food. Under the sea, and not very far at that, are living creatures going about their daily lives.Conch ©Melinda Riger @G B ScubaConch ©Melinda Riger @ GB Scuba

And that includes reproducing. This sounds as if it might be a cumbersome process, but (like porcupines) they seem to manage. Here is a pair preparing to mate. The male behind is presumably about to… well never mind. I’ve never seen the process, so it’s a case of using imagination. Or just accepting that, whatever it is that they do, it works. [I haven't located a video online - I'll post one if I do]Conch preparing to mate ©Melinda Riger @ GB Scuba

You’ll find some more about Conchs in a previous post HERE, including 12 Unputdownable Conch Facts, notes on conservation matters and… a photo of Honeychile Rider, arguably the most famous conch-carrier ever. Oh, she was fictional, you say? But I always though she… How very disappointing.

And if you want to know how to clean a conch, a dude will  show you in a video on this page HERE 

Finally, check out the very informative website COMMUNITY CONCH, a charitable conservation organisation community conch logo

Photo credits: Melinda, Clare, RH

‘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

FLAMINGO TONGUE SNAILS & SHELLS: COLOURFUL GASTROPODS OF THE CARIBBEAN


FLAMINGO TONGUE SNAILS & SHELLS: COLOURFUL GASTROPODS OF THE CARIBBEAN

The FLAMINGO TONGUE SNAIL Cyphoma gibbosum is a small sea snail (marine gastropod mollusc), related to cowries. The live animal is brightly coloured and strikingly patterned, but that colour is only in the ‘live’ parts – the shell itself is pale and characterised by  a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and wider western Atlantic. Whether alive or dead, they are easy to identify.

This snail on the left (thanks, Wiki) is snacking on a coral stem, leaving a feeding track behind it. The structural shell ridge is clearly visible beneath the distinctively marked live tissue.

The flamingo tongue feeds by browsing on soft corals. Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore predation by C. gibbosum is generally not harmful to the coral.

The principal purpose of the mantle of  tissue over the shell is as the creature’s breathing apparatus.  The tissue absorbs oxygen and releases carbon dioxide. As I have seen it described (unkindly?) “it’s basically their lungs, stretched out over their rather boring-looking shell”. 

This species was once common but is becoming rarer. One significant threat comes from snorkelers and divers who mistakenly think that the colour is the shell of the animal, collect up a whole bunch, and in due course are left with… (see photos below)

These photos are of flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I thought everyone thought they were rather lovely… you decide!

Finally, a couple of videos. The first is rather charmingly titled ‘FLAMINGO TONGUES DOING…. SOMETHING’. Any (printable but amusing) suggestions via the Comment box are welcome (Hi Trish!). The second punchily summarises this post. Maybe that’s all that was needed!

ABACO SHELLS: 3 MORE FROM THE DELPHI CLUB COLLECTION


ABACO SHELLS: 3 MORE FROM THE DELPHI CLUB COLLECTION

I have recently featured some of the shells from the collection amassed at Delphi –  see SHELLS 1 and SHELLS 2. They are kept in vases or bowls for display and examination. They may not all come from the immediate vicinity, but they are all, for sure, from South Abaco. It’s time for some more.

PINK TRIVIA SHELL

 

LETTERED OLIVE  SHELL

  

COMMON SPIRULA  

For further details about Spirula(e), please see the comment box where Capt Rick Guest gives a lot of fascinating info about them and related marine cast-offs. You’ll also find out which are the real prize ones to look out for…

  A vignette of RH examining shells on the balcony at Delphi 

 

TULIP SHELLS & SUNRISE TELLINS: MORE BEACHCOMBING TREASURES FROM ABACO


TULIP SHELLS & SUNRISE TELLINS: MORE SHELL TREASURES FROM ABACO

Here are two contrasting shells from the Delphi Club collection that has been haphazardly accumulated over the last 3 years or so. The first post in this shell series was about SEA URCHINS & SEA BISCUITS

TULIP SHELLS Fasciolaria tulipa

The term ‘Tulip snail’  includes 3 related species of sub-tropical gastropod worldwide, of the genus Fasciolaria. They are medium-sized predatory molluscs that breed throughout the year in warm waters. Their reproductive lives deserve some attention, if they will pardon the intrusion. 

Research by the Smithsonian Marine Station Fl. reveals that the male’s penis is to be found on the right side of its body, directly behind its head… When they mate the (larger) female stays in an upright position on the sand while the male ‘flips over’ to align the apertures of both shells, before inserting the penis into the female (RH comment: the research is not specific about precisely where the female keeps her own genitals). Once joined, snail pairs may remain locked together for up to 2 hours, even when being watched by researchers. They have plenty of stamina: mating may occur several times in one season, and individual tulip snails have been observed to mate up to 3 times in a single week. Respect!

SUNRISE TELLINS Tellina Radiata

I included these pretty shells, with their striking pink radials, in an earlier post BEACHCOMBING BIVALVES The ones shown here are larger specimens. The hinges (muscles) are very delicate, and in these shells the two halves of the shells have separated. STs are not uncommon, but these are the largest I have come across (I realised after I had taken the photos that I should have used a coin for comparison…). They grow up to about 7 cms, and  these ones were that length, or very nearly so.

I can’t assist with their sex lives I’m afraid, which may well be completely conventional, dull even. However, as I discovered when I previously researched these shells,  “in most countries it is illegal to bring back these shells from holidays”. To which I can only repeat my comment: Whoops!

BAHAMAS CONCH QUEST – GASTROPODS, SHELLS & CONSERVATION


BAHAMAS CONCH QUEST – GASTROPODS, SHELLS & CONSERVATION

Conchs are among the most familiar of all shells. On Abaco they are everywhere: in the sea, on the beach, used ornamentally in gardens, piled up wherever conch is on the menu… (basically, anywhere serving food)

Conchs have other uses besides being a staple food. They provide sought-after pink pearls.  Only about 1 conch in 10,000 has a pearl, so bear in mind that if you miss one during your search, you may have another 10,000 to wade through… Conchs can produce music, of a sort (such as when used enthusiastically by the famous ‘conch-blower’ home-team supporter during cricket Test Matches in the West Indies). They are undeniably decorative on a porch or on a shelf.

Conchs have featured in literature and film. In William Golding’s Lord of the Flies the conch represents power and order. A conch is blown to call meetings of the marooned boys. Its power is symbolised by the rule that you have to be holding it to speak at the meeting (an idea that many – all? – Parliaments could benefit from…)

Ian Fleming mentions conchs in several of the Bond books, all such references being totally eclipsed by the memory of the appearance, in the film Dr No, of Honeychile Rider emerging from the sea, conch in hand. Oh, I see. That’s just men is it? Or (good grief) just me? Anyway, may we all agree amicably that Ursula Andress was a most decorative conch carrier?

CONCH CONSERVATION

The supply of conchs is not infinite. Overfish them, take them before maturity  or pollute their habitat and this valuable marine resource depletes – and conchs, as with so many marine species, will become threatened. Fortunately there is a Bahamas-wide conservation organisation with a website packed with interest. 

COMMUNITY CONCH is “a nonprofit organization that aims to protect queen conchs in the Bahamas, a species of mollusk threatened by aggressive over-fishing. We promote sustainable harvest of queen conch through research, education and community-based conservation”

community conch logo

“Helping to sustain a way of life in the Bahamas”

Much of the research has been carried out in Berry Is, Andros and Exuma Cays. However the team has recently been based at Sandy point, Abaco. To see some of their work on Abaco CLICK LINK===>> ABACO EXPEDITION   

In many past posts I have listed ’10 Essential Facts’ about the topic discussed. In that spirit I have borrowed and slightly edited CC’s conch facts; and added a CC video of a conch’s stately ‘full speed ahead’ progress. NB No zoom… 

12 CONCH FACTS

  • The queen conch is a large edible sea snail native to the coasts of the Caribbean, the Florida Keys, the Bahamas, and Bermuda. Conchs are herbivores – they eat algae and other tiny marine plants
  • Main predators include nurse sharks, loggerhead turtles, other snail species, blue crabs, eagle rays, spiny lobsters, and other crustaceans
  • Mating aggregations may contain hundreds or even thousands of individual male and female conchs
  • Female conchs lay hundreds of thousands of tiny eggs in a sandy egg mass. The larvae emerge after 5 days and may drift on ocean currents for a month before settling in suitable habitat on the sea floor
  • In their first year conchs live under the sand during the day & come out to feed on the surface at night
  • A queen conch may take 5 years to reach maturity and can reproduce
  • They live an average of 7 years, but are known to live as long as 20 – 30 years
  • Conchs produce natural pearls that come in a range of hues, including white, brown, orange & pink
  • The conch is listed by CITES as a species which may become threatened with extinction if trade is not tightly controlled
  • It is now illegal to take queen conchs in the state of Florida due to severe overfishing
  • 80% of legal internationally traded conch is consumed in the United States. The smuggling of conch meat into the U.S. is a significant challenge to conch management in The Bahamas
  • Queen conch are vulnerable to overfishing because they are (1) relatively slow to grow (2) late to mature (3) aggregate to mate (4) easily harvested in shallow waters

A SPEEDY CONCH

(Conch photos taken by RH / Mrs RH at Sandy Point, Abaco)

BEACHCOMBING WITH KASIA: EXPLORING A ROCKY SHORE


Kasia’s back! She recently explored a rather unpromising-looking stretch of Abaco coastline, and it proved to be anything but… Kasia writes: The story goes: one day I took myself for a walk and a bit of beachcombing. I usually don’t bring my camera with me but luckily this time I did. This particular beach looks very barren but on close inspection and a patient eye there are some lovely treasures to be found. Here are some of the treasures I captured!

A tangle of 3 bleached trees, with their roots apparently intertwined

CHITONS

Great close-ups… are those eggs behind this first one? There’s a similar image in the Macmillan ‘Marine Life of the Caribbean’ but unfortunately neither the caption nor the text refers to them. ADDENDUM: Colin Redfern writes: The “eggs” behind the chiton are fecal pellets

NERITES (Nerita)

 

WEST INDIAN TOP-SHELLS (Cittarium Pica) 

In this image, several very small chitons can also be seen on the rock

It looks as if someone… or something… has been having a Nerite feast on the shore. A bird maybe?  I had taken the shells above and below to be another variety of Nerite, but as so often scientist and shell expert Colin Redfern has kindly corrected the error. He writes: “Very nice photos. The “nerite feast” is actually a pile of broken West Indian Top-shells (Cittarium pica). The photo immediately above shows a live group of the same species. This is what Bahamians call a whelk (or wilk), and in the lower photo they have been harvested, probably for a stew.

 ROCK POOL MISCELLANY

I am trying to ID a much as I can in this pool. All suggestions welcome via ‘Leave a Comment’. So far, the corals are Brain Coral and Pink Coral (I think) but I am going see what else can be given a name…

These are my favourite! :) Kasia

COMET SEA STAR (possibly juvenile, with 3 such short stubs?)

A SPONGE (?) OF SOME SORT (any help with ID appreciated…)

                RED ROCK URCHINS

SHELLS OF THE ATLANTIC COASTS & WEST INDIES: PETERSON FIELD GUIDE


SHELLS OF THE ATLANTIC COASTS & WEST INDIES 

PETERSON FIELD GUIDE    Abbott / Morris   350pp

An excellent and comprehensive field guide which covers the area as thoroughly as one could wish. It’s not exactly a pocket book, and at 350 pages it’s quite a chubby paperback – but the sort of size you’d happily throw into a day-bag or backpack. This authoritative shell guide dates from 1947, with frequent reprints. Mine is a fourth edition (1995) – there may be a 2002 one.

Currently £18 from Amazon UK,  or new / used for around £7 (a bargain); and a great deal cheaper on Amazon US. Overall 4* reviews

Rolling Harbour rating *****

THE BOOK IN A CONCH SHELL

  • Numerous clear illustrative line drawings throughout (115, in fact)
  • 74 colour plates grouped together at the heart of the book, showing living creatures and a huge variety of shells – 780 in all
  • Introductory articles on collecting, preparing, arranging and naming shells; also classifications and measurements
  • The text comprises 800 brief but helpful family / species descriptions, with notes on habitat and other remarks
  • Bi-valves cover 120 pages; Gastropods a stonking 150 pages
  • The substantial illustrated core of the book has shell groups on the right-hand page, with ID and text references on the left. The system works very well, especially with the many shell types that are very similar
  • At the back there’s a useful ‘Conchological Glossary’ to help sort out the crenulates from the reticulates
  • A huge 30-page index that is both thorough and user-friendly
I personally found the illustration section very helpful as a first stop; then a trip to the text to confirm the description. I had no idea what a shell we recently found in a drawer might be, but it didn’t take long to nail the ID as a STOCKY CERITH a shell I’d never even heard of. First I found a very clear illustration of it, then turned to the text description which matched what I had in my hand. Overall, as a complete amateur, I found this book the best practical guide I have yet tried for shell identification – and I suspect more sophisticated shell-seekers will get a great deal out of it too.

KING VENUS CLAMS & CRAB SHELLS (NO SPACE DEBRIS): ABACO BEACHCOMBING WITH KASIA


ANOTHER STROLL ALONG THE SHORE WITH KASIA

After all the recent excitement – well I was excited, anyway – involving Mars Mission space rocket debris washed up on the Delphi Club Beach CLICK MARS ROVER it’s a gentle touchdown back onto a sandy beach for some more of Kasia’s finds. First, a shell which I believe (tempting fate) I have correctly ID’d for once. Then a half crab shell, at a guess a spider crab’s roof. 

KING VENUS CLAM Verenidae – Chione Paphia

These bivalve molluscs seem to be inoffensive, and to lead rather dull lives: so far all I have discovered is that “they live buried in sand at depths of 1 – 20 fathoms” I shall investigate further & report back – there must be some small creature they molest or upset in some way…

CRAB SHELL, FORMER HOME TO A SPIDER CRAB

KASIA’S MYSTERY ABACO SHELL: A PUZZLE FOR XMAS


KASIA’S MYSTERY ABACO SHELL: A PUZZLE FOR XMAS

Kasia’s beachcombing exploits have produced some lovely seashells that have already featured here. Precise identification has sometimes been difficult for an amateur, because of the many varieties of a particular type of shell or close resemblance to other shell families. This one has got me stumped. I have trawled the  internet. I have studied field guides. I’m still baffled. It hasn’t quite matched any other shell…

XMAS PRIZE the first person to ID this shell correctly will enjoy a bottle of ice-cold Kalik being drunk on the Delphi balcony swing in February 2012. By me. Suggestions to rollingharbour.delphi@gmail.com welcome

STOP PRESS: NOW SOLVED – SEE UNDER IMAGES

Helpful thoughts: I’ve considered a  form of King’s Crown (but I’ve not found a close enough match) or a Ram’s Horn Snail (but they don’t seem to have spines)

First entry by Kasia (potentially disqualified as the shell’s owner): Angaria, a form of Turban shell. However these seem to be confined to Pacific areas…

The Solution:  And the winner (within 24 hours) is… Kasia!

I sent the link to the post to Bahamian seashell expert Colin Redfern at http://www.bahamianseashells.com, author of ‘Bahamian Seashells: 1000 Species from Abaco, Bahamas’. He confirms Kasia’s ID as an ANGARIA SHELL , one of a large number of species of turban shells TURBINIDAE found throughout the world. It is indeed a Pacific shell, probably from the Philippines. So what on earth was it doing on a beach on the east coast of Abaco? Colin has encountered this sort of anomaly before, and gives various possible explanations:

1. Homeowners’ shell collections come from areas other than the Bahamas & are sometimes thrown out onto a beach. They may be washed up along the coast

2. Shops sell packets of shells, including Pacific shells, which may become dispersed

3. In Fl. it is not unknown for resorts to “seed the beach” with Pacific shells, which are cheaper & more easily bulk-bought than Atlantic shells

4. Rare Pacific & Indian Ocean shells washed up on a beach were once traced to the owner, whose beach house had been lost in a hurricane some years before

Many thanks, Colin, for your help with this puzzle; and congratulations Kasia – I’ll claim my Kalik in February please. Oh I see, I’ve got to buy you one, have I?

PETERSON CONCISE GUIDE TO SHELLS OF NORTH AMERICA: REVIEW


PETERSON CONCISE GUIDE TO THE SHELLS OF NORTH AMERICA

This pocket guide is part of the well-known Peterson series of natural history guides. It’s called a ‘First Guide’ to denote its ‘beginner’ / condensed status, and to distinguish it from the serious business of the excellent and comprehensive Peterson Field Guides (I shall review 2 of these in due course. When I have read them. In 2012).                                  rh rating **

SUMMARY: this 128pp ‘concise field guide to 224 common shells of North America’ is a simple pocket guide, with quite basic descriptions, and colour drawings rather than photos. All the main gastropod and bivalve species are represented, each with a few variants. The vast majority of these will be found on Abaco and more generally in the northern Bahamas. For the used price I paid for a 1989 edition with a creased front cover (1 pence + P&P on Amazon UK!) I have actually found it quite useful for comparing or confirming IDs, or for snippets of additional information. However, it’s not the one to rely on entirely to identify your beachcombing finds or to get species details. Apart from anything else the illustration colouring is often somewhat approximate. At best, I’d say it’s a useful preliminary tool for ID on the beach if you don’t want to lug a much larger field guide around with you. Don’t use it for your doctoral thesis. Overall, some use, but not a great deal. There are better books: see FISH & SHELL BOOKS

MUREX & TRITON SHELL COLLECTING ON ABACO WITH KASIA


PAGE REWRITE IN PROGRESS

MUREX (MURICIDAE) & TRITONS (RANELLIDAE) 

1. MUREX SHELLS (Muricidae)

This is a vast family of shells worldwide, with many subspecies, each of which has many regional variations. Or even variations of the same subspecies on the same beach. Many have beautiful delicate spines or intricate shapes and elaborate patterns, like the pacific one shown

These molluscs are described as ‘voracious rock scavengers’ and exhibit uninhibited psychopathic tendencies. If you have a nervous disposition, stop reading here; Sam Peckinpah missed a great film collaboration with Jacques Cousteau with these vicious little creatures

10 ESSENTIAL YET GRISLY MUREX FACTS

  • Murex are highly carnivorous with rasping teeth, and drilling equipment for boring into the shells of their prey
  • A determined Murex may take up to 5 days to drill into its prey
  • Murex also use their foot to smother prey, or to crush it by using suction power
  • They eat clams by hoovering them up with their foot and smashing them on rocks to get at the occupant
  • They happily eat sea-floor carrion and sea-kill
  • Murex act in packs to carry out raids on unsuspecting beds of clams, which they feast on avidly
  • They are sexually wanton. Females store sperm from different males for many months, eventually producing embryos with different dads (I’m not making this up. I would like to have done so)
  • Cannibalism occurs. The kids are equally prone to extreme delinquency and are happy to eat each other when peckish
  • Some species of murex secrete a fluid that is believed to be used to drug their prey into paralysis
  • That same fluid (Murex / Mucus) is also used as a dye, ‘Tyrian’ or ‘Royal’ Purple, which can be ‘milked’ from a living murex (the Aztecs & Phoenicians did this). I’ll pass on that

NEW: VIDEO of how to obtain dye from a Murex

 KASIA’S BEACHCOMBED ABACO MUREX SKELETON

TWO MUREX SHELLS OF MINE (NOT FROM ABACO) FOR COMPARISON  DETAIL OF COLOUR & SHINE

2. TRITON SHELLS (RANELLIDAE)

KASIA’S TRITON TROPHY FROM CASUARINA, ABACO

Here is another shell from Kasia’s beachcombing in the Casuarina Point area on Abaco. I’ve never seen one like this. I thought it was a TROPHON, a variety of the huge MUREX family. As I wrote, there are more than 30 types of trophon world-wide, many with a similar configuration, though I hadn’t managed to find one with a similar colouring and shell growth-pattern yet. I invited  confirmation or correction, which Colin Redfern kindly provided. It is in fact a fine example of a…

 

DOG-HEAD TRITON Cymatium cynocephalum

ANGULAR TRITON Cymatium femorale                                                                                A different sort of triton found by Kasia


BEACHCOMBING AT CASUARINA, ABACO, WITH KASIA – COWRIE / PHALIUM / CONCH


 BEACHCOMBING AT CASUARINA WITH KASIA                    COWRIE / PHALIUM & CONCH

I recently posted some photos of starfish taken by Kasia at low tide near Casuarina point – see KASIAS’S STARFISH. Now it’s time for some beachcombing news from there. The sandbanks and bars in the Casuarina / Cherokee Sound area are a rich source of conchs, sand dollar tests and shells of many varieties when the tide is out. The sandy areas revealed as the water slowly recedes are extensive, and it is a great place to hunt for specimens (and for a lunchtime break from bonefishing…)

COWRIES / PHALIUM

1. RETICULATED COWRIE-HELMET Cypraecassis testiculus Here is a pretty example of this shell, a relative of the large phalium family and originally misidentified by me as a Phalium granulatum

2. MEASLED COWRIE  Macrocypraea zebra / Cypraea zebra Colin Redfern says of this example “Immature shells have transverse stripes that are later covered by a spotted layer (hence “measled”). It looks as if it’s beachworn rather than immature, so the outer layer has probably been worn away. You can see remnants of the spotted layer adjacent to the aperture.” 

STOP PRESS: by coincidence, while looking for a completely different type of shell online I have just happened upon this early 1800s engraving of a Cypraea Vespa, which is very similar to Kasia’s one

CONCH I’m trying not to overdo Conchs, which are probably everyone’s favourite shell to collect. But this one is a wonderful pink, and came with a surprise inhabitant… Is anyone at home?

Oh! A hermit crab seems to have moved in…

It’s shyer than this one (from an unnamed online source)

Finally, a useful method to transport one’s shell collection, maybe?

ABACO BEACHCOMBING: TWO CONCH SHELL SKELETONS


ABACO SHELL SKELETONS

Besides ‘living shells’ with occupants in residence and shiny recently-vacated shells, there is a third category of shell: the skeleton. I am sure there’s a better or more technical word for these. They aren’t fossils in the strict sense of remnants from a past geological age, but merely worn by the waves and bleached by the sun over time. Here are two examples (from different beaches) which show the intricacy of the part of the shell you don’t normally see: the interior

A shell skeleton from Little Harbour, in situ on the beach on a cloudy day

The same shell washed, with a wonderful pink tinge in sunlight

A strange corkscrew skeleton shell from Sandy Point. I’ve no idea what it is, nor how any creature can have lived in or around it, nor what it must have looked like when complete. Any ideas? Please use the comment box… Thanks, Kasia, for your ID of both as conch skeletons. The first obviously is, but the second puzzled me… until she pointed out that conchs build their own shells round themselves to their own designs rather than go to the one-stop conch shell shop. So if a conch starts wrapping itself comfortably round its own corkscrew, this is what you get

(Mrs rh quite rightly points out that my shell photos are unhelpful without a ruler to give an idea of size. Point taken. Too late. These are medium size…)

SCOTCH BONNET SHELLS (Phalium / Semicassis) ON ABACO


Scotch bonnets (or ‘ridged bonnets’) Semicassis granulata or Phalium granulatum are a medium-sized species of sea snail found in the tropical and subtropical western Atlantic from North Carolina to Uruguay. They are predators, foraging on sandy stretches of the ocean floor for echinoderms such as sand dollars, sea biscuits, and other sea urchins (Caution: ‘Oxford comma’)

 SCOTCH BONNET FACTS
  • It takes approximately six years for a Scotch bonnet to mature
  • The shells grows 2 – 4 ins long (5 – 10 cm), showing distinct growth stages
  • Scotch bonnets live on sand, usually in fairly shallow water (but see below)
  • The more a Scotch bonnet eats the more elaborate its shell, the glossier its sheen & the brighter its colours (research suggests this doesn’t work for humans)
  • Divers frequently find Scotch bonnets at depths of 50 – 150 feet (15 to 46 m). Specimens have been found in depths up to 308 ft (94 m)
  • Shipwrecks provide a good habitat for this species
  • Crabs are its main predators, crushing the shell to get at the occupant. Since the snails’ main defence mechanism is to withdraw into their shells, they urgently need to evolve a new tactic
  • The empty shell of this sea species is often used by hermit crabs
  • In 1965 the state of North Carolina made the Scotch bonnet its official state shell, in honor of the Scottish settlers who founded the state

The ridge on my shell, below, may be somewhat unusual. I haven’t found any images showing such a very distinct dorsal growth, though many show a sort of fault line there. STOP PRESS shell expert Colin Redfern explains: The dorsal ridge on your shell is a varix, indicating a previous position of the outer lip during the growth process. Varices on Scotch Bonnets are usually thicker (as in the image above).”

dear wiki: how kind to help

CASSIS RUFA (Cypraecassis rufa)

There are many different sorts of Phalium worldwide. By way of comparison, here is another type, Cassis Rufa, from the Pacific (commonly, east Africa to New Guinea). It’s colloquially known as a Bullmouth, Red Mouth or Grinning Mouth Helmet –  and also as a ‘Cameo Shell’, because it is often used for making cameos (see eBay for examples)

        [rh provenance / historical note: it's not an area I've ever been to, nor am I likely to go. This shell was collected by my late father-in-law when he oversaw the building of the original Gan airstrip on Addu Atoll (Maldives) in... in.... many years ago, as a naval project. It is now 'Gan International Airport' and sells giant Toblerone & 'Parfum de Jordan' from the Katie Price 'Scentsless' range]

BEACHCOMBING ON THE DELPHI BEACH, ABACO (PT 2): BIVALVES


This is Part 2 of the ‘Delphi Beachcombing’ feature. The first dealt mainly with gastropods, and now I have got round to some bivalves. All the shells illustrated come from somewhere within half a mile of the Delphi Club beach steps, except for the sunrise tellin. We gave ours to our granddaughter (5) [she likes pink, but also mud] and it has… somehow come apart. 

EGG COCKLES Unlike the vast majority of cockle types which have the familiar radial ribs, egg cockles are smooth and non-ribbed. They are apparently able to jump by flexing what passes for their leg – a feat I would enjoy seeing…

GAUDY ASAPHIS Asaphis Deflorata (formerly ID’d as COQUINA Donax)

TIGER LUCINE Codakia orbicularis (formerly ID’d as ELEGANT DOSINIA Dosinia Elegans)

SCALLOP / PECTEN This is not a ravenelli, as previously suggested by me –  they are deep water molluscs.  It’s hard to be sure exactly what species it is, in such a bleached state.The tiny shell half is surely the basis for the symbol of a petro-chemical giant that I decline to identify further. I thought this one was broken but a check shows that the asymmetry of the hinge is very common. Encrustation by worms, as here, is often found as well, but I wisely draw no parallel with the litigious petrochemical industry…

SUNRISE TELLIN (Tellina Radiata) Tellins are a genus with masses of variants worldwide. This species is common in the Caribbean. It is a really pretty shell, glossy with pink radials. They grow up to 7cms. As hinted above, if you find a complete one, the hinge is delicate. The most interesting fact I have discovered is that “in most countries it is illegal to bring back these shells from holidays” Whoops!