NEW PAGE IN ‘MARINE LIFE’ CATEGORY FOR SHELLS. CORALS HAVE BEEN SHUNTED OFF TO THEIR OWN PAGE CORALS (All videos give credit info)

Kind reader(s) Dec 2011 Abaco shell expert Colin Redfern has been through this page with a fine shrimping net. Many of the ID’s can be improved – or, let’s be frank, are quite simply wrong. sorry about that. a major rewrite will take place when i have  stopped blushing – january 2012, let’s say… NOW DONE

 A RANDOM ABACO SHELL FROM THE BACK OF A DRAWER 

We recently discovered this shell loitering at the back of a drawer. It may well have been there for a couple of years… I had no idea what species of gastropod it might be, so I turned to a book I recently bought (and am about to review), the Peterson Field Guide on Shells. It is extremely thorough and well-illustrated, and almost at once I was able to pick the shell out as a STOCKY CERITH Cerithium Litteratum (Colin – are you still keeping an eye on the shell ID errors in this blog, I wonder?). It’s a couple of inches long and has 7 spirals before the tip part, with pronounced nobbles on the lowest 4. There’s a neat hole in it, but I don’t know whether caused by sea / beach damage or a predator. These creatures live in shallow water and are common throughout the Caribbean. So this one is nothing unusual, but I am pleased that it has eventually turned up…

STOCKY CERITH Cerithium Litteratum

CONCH CENTRAL AT SANDY POINT, ABACO

The serious conch action in Sandy Point is to be found at the jetty. I learned a simple beginner’s lesson on our first visit to Abaco. If you choose a large gorgeous-hued conch from the huge pile in the 4th photo to take back home, it will quickly start to smell dodgy, followed by evil… until you clean it properly!

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…

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 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?

MUREX (MURICIDAE) & TRITONS (RANELLIDAE) 

1. MUREX SHELLS (Muricidae)

2. TRITON SHELLS (RANELLIDAE)

KASIA’S TRITON TROPHY FROM CASUARINA, ABACO

SHELLS FROM KASIA’S BEACHCOMBING COLLECTION

COWRIES AND 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

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…)

CASSIS SHELLS (PHALIUM)

1. 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 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

2. 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 & 'Eau de Jordan' from the Katie Price 'Scentsless' range]

BEACHCOMBING ON THE DELPHI CLUB BEACH PART 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 form 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. NB 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!

CONE SHELLS (CONUS)

Conus is a species of predatory sea snail, mostly tropical. There are more than 600 types. This one is a beachworn Mouse Cone Conus Mus. All are carnivorous and to some extent venomous. The venom of the larger species is powerful enough to kill a human. These catch small fish using (I hope I’ve got this) a sort of toxic dart or harpoon, fired by muscular contraction, paralysing the prey which is then retracted to the mouth for digestion. They can even fire backwards. Good grief! Exactly the super-power I would like to have. You will see that this cone has lost the tip of its spiral. There are two explanations: (1) it broke off while or after being washed up on the beach or (2) a predator has cracked it off in order to get at the occupant.

Many types of cone have very colourful patterns – they are often use for jewellery or decoration. Don’t pick up a large live one – the conus will defend itself and its ‘harpoon’ can penetrate a wetsuit or gloves. The toxic effects sound gruesome and nb there is no anti-venom: treatment involves “providing life-support until the venom is metabolised…” Reassuringly the sting of small cones is “similar to a bee sting…” An upside is that Cone venom apparently has medical promise for a variety of afflictions including Parkinson’s disease.Thanks to Colin Redfern for positive ID as a  beachworn Mouse Cone Conus Mus

I can’t positively identify my own cone. Having looked at dozens of images, I discover (thanks again, wiki) that “This genus shows a large variety of colours and patterns, and local varieties and colour forms of the same species often occur. This has led to… a large number of known synonyms and probable synonyms, making it difficult to give an exact taxonomic assignment for many snails in this genus”. So I’ll leave it simply as an Abaco cone.

Here is a size comparison with a small sand dollar, and two pieces of coral featured in CORALS .

NERITES (Nerita)

Nerites are small sea-snails (gastropod molluscs) found in tropical waters around the world. Precise ID of the many types is confused by the different names used for many of them, both taxonomic and local. The majority of the black and white nerites in the pile below, all collected from the Delphi beach, are Checkered Nerites (Nerita Tessellata). In the heap there are a few larger whiter shells with red markings, which are the Four-Toothed Nerite (Nerita Versicolor).

Here are some of the above shells showing their varying patterns and sizes, seen with a few grains of sand for comparison. The 3 larger whiter ones with the flecks of red on them are the Four-Toothed Nerites.

Here are 3 example shells in close-up, together with a tiny, perfect Dwarf Atlantic Planaxis Hinea lineata at the end. I didn’t notice it until I was sorting through the shells – in fact you can just see it towards the bottom right of the previous photo, above the small nerite that’s on its back. It may even have fallen out of a nerite, as did many of the sand grains.

These four upturned nerites show the dentate entrance, common (to a greater or lesser extent) to most nerites – maybe all. The top row are Four-toothed Nerites; the bottom row are Checkered Nerites. Another Nerite type found in the Bahamas is the Bleeding-tooth nerite (Nerita Peloronta). These are similar to the top ones, but have vivid orangey-red markings on the ‘teeth’ – hence their name

Nerites, sand grains and the planaxis: size comparison.

A close up of the planaxis, showing how amazingly detailed the pattern of such a tiny shell can be.

All this may sound a bit learned and somewhat solemn. Dull even. In fact I had absolutely no idea about any of the above details until I got these shells out of their glass jar last week to photograph (apologies for using a chopping board) and did some digging. So if any shellologists or neritophiles read this and have corrections to suggest, be my guest… Use the comment box or the email address on the CONTACT page.

Huge thanks to Colin Redfern for taking the trouble to clarify and correct some of the IDs of shells on this page. For the novice, it turns out to be quite a minefield of varied terminologies and reclassifications.

LIVING SAND DOLLAR ON ITS BACK – VIDEO

This video shows how the sand dollar is able to get around and to bury itself in the sand by using the hairs on its underside:

SAND DOLLAR IN A SPIN – TIME-LAPSE VIDEO

Another short time-lapse video of Sand Dollar manoeuvres lasting 15 – 25 minutes in real time, this time moving in circles before suddenly ‘zooming off’ into the distance…

SAND DOLLARS FROM THE RH COLLECTION

A small Sand Dollar test from Rocky Point beach near Sandy Point (top side, underside and see-through)

Large Sand Dollar tests from a sand bar in Cherokee Sound

A FISTFUL OF SAND DOLLARS…

Scientific Classification Kingdom: Animalia; Phylum: Echinodermata; Class: Echinoidea; Subclass: Euechinoidea; Superorder: Gnathostomata; Order: Clypeasteroida (wiki-prompt)

SAND DOLLARS - 17 ESSENTIAL FACTS

Sand dollars are a species of burrowing sea urchin with five-fold radial symmetry

Live animals have a skin densely covered with soft hairy spines

They may appear to be green, blue, violet or purple in colour

They move over the sand, or burrow in it, using their spines

Their mouths are on the underside, at the centre of the petal pattern

They eat tiny larvae, plankton, microscopic organisms and algae. Veggie dollars stick resolutely with the algae

They have 5 sections – ‘teeth’ – for grinding their food

Digestion takes up to 2 days

They live in the deep ocean, so it is unusual to meet a live one

Their rigid skeleton discs are known as ‘tests’

The white colour of the tests result from bleaching by the sun after they are washed up onto sandbanks and beaches

They are also known as sea cookies, sea biscuits, sand cakes and cake urchins

Burrowing in the sand is their defence against predators and rough water

They can weigh themselves down by swallowing grains of sand

The lifespan of a sand dollar is between 6 and 10 years

Exact age can be established by counting growth rings (cf trees)

750 sand dollars may live in 1 square metre of seabed

(Info Sources – many & varied open-access scraps blended into one eezy-2-read blog format. Thanks, everyone. Legal teams please note: this is emphatically research, not plagiarism. Ok, prove it then)

An unusual species of Sea-Biscuit, Laganum Oleae Nigrae (“Black Olive Cracker”)

THE SAND DOLLAR: A STATELY PROGRESS ACROSS THE SAND

A (very) short time-lapse video of a sand dollar moving. On sand. Leaving a little trail. It won’t win the echinoid Grand Prix, but it’s quite entertaining in its way… Apologies for any pop-up ads on-screen… google-omnipotence rules – and ‘accross’ (sic).