TAKING A CLOSER LOOK: ROCK POOLS ON ABACO


Rock Pool, Abaco 2

TAKING A CLOSER LOOK: ROCK POOLS ON ABACO

Here’s a promising-looking rocky outcrop a short distance south of Crossing Rocks. The action of the sea over centuries has eroded and pitted it – ideal for the formation of pools in which marine life can thrive.Rock Pool, Abaco 1

Time to clamber up to see if the theory holds good… the prospects are encouraging. There are certainly plenty of sea urchins here.Rock Pool, Abaco 4

Let’s zoom in on the nearest pool. There are clearly 2 different-coloured sea urchins here, but I’m not sure if that’s an age thing or a species thing. Rock Pool, Abaco 6

Apart from the sea urchins, there are some shells and other things that need a closer look…Rock Pool, Abaco 5

At the bottom of these photos, you can see that a zebra-marked nerite is quite happy to share a hole with an urchin. There are two brownish accretions on or in the rock. My tentative suggestion is that these are the shells of some sort of worm, perhaps petaloconchus.

UPDATE Rick Guest helpfully comments “Yes, it’s quite the invertebrate hotel mostly due to the urchin’s talent for scouring out protective “rooms”. Of interest is the Magpie shell (Livona pica) in frames 4 and 5. The rather ubiquitous Livona’s very thick shell, (Up to 5″ diameter) and ability to withstand most attempts at removal by predators, including Homo sapiens, assures their continued presence on littoral shore lines. They are edible, but not particular tasty to my palet. All these “Condo” residents “party” at night and will even leave the rock in search of food and perhaps romance, so a flash pic of the condo at night would be an interesting contrast to a daylight shot”.ROCK POOLS, ABACO 11

In a snug little cave (top right) just above the water-level of the pool is a primitive-looking chiton, a species that has been around for millions of years. Below, there’s a clearer image of one from a different pool. These creatures always remind me of school projects on prehistoric trilobites.Rock Pool, Abaco 7Rock Pool, Abaco 10

The rough rocky surfaces close to the pool are covered in shells. The stripey nerites are small, the grey shells really are miniature.  They are mostly littorines/ periwinkles and perhaps ceriths, I think.Rock Pool, Abaco 9Rock Pool, Abaco 12

Close-up views of nerites showing their distinctive markings and spiralsRock Pool, Abaco 13Rock Pool, Abaco 14

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

‘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

KING HELMET SHELLS (Cassis tuberosa) MORE DELPHI CLUB SHELLS


KING HELMET SHELLS (Cassis tuberosa) FROM THE DELPHI COLLECTION

It’s time to look at another shell from Delphi. The club has glass jars displaying small shells in the Great Room. Larger shells like the ones below are displayed on shelves. The King Helmet is the largest of the helmet shells of the family Cassidae. They are found in the Western Atlantic from North Carolina through the Caribbean and the gulf of Mexico down to Brazil. They tend to bury themselves during the day, becoming active and feeding at night. In humans this behaviour is found mainly in students and in those involved in the music business and similar louche occupations.

King Helmet Shell 1 King Helmet Shell 2

King Helmets prey mainly on sea urchins and other echinoderms, using their foot to grip their meal. The dining arrangements are somewhat protracted. The snail makes a hole in the urchin through the combined action of a glandular secretion which is rich in sulphuric acid, while using its RADULA to rasp and dig through the shell to get at the trapped occupant, which it gradually consumes… That’s enough about that.
King Helmet Shell 3
King Helmet Shell 4

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!

STOCKY CERITH – A RANDOM ABACO SHELL FROM THE BACK OF A DRAWER


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? Later: yes… and he confirms the ID. Many thanks). 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