TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS


Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

Painted Tunicates Clavina picta are one of several species of tunicate ‘sea-squirts’ found in Bahamas and Caribbean waters. These creatures with their translucent bodies are usually found clustered together, sometimes in very large groups. One reason for this is that they are ‘sessile’, unable to move from where they have taken root on the coral.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

HOW DO THEY FEED?

Like most if not all sea squirts, tunicates are filter feeders. Their structure is simple, and enables them to draw water into their body cavity. In fact they have 2 openings, an ‘oral siphon’ to suck in water; and an exit called the ‘atrial siphon’. Tiny particles of food (e.g. plankton) are separated internally from the water by means of a tiny organ (‘branchial basket’) like a sieve. The water is then expelled. 

Diagram of adult solitary tunicate

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

WHAT DOES ‘TUNICATE’ MEAN?

The creatures have a flexible protective covering referred to as a ‘tunic’. ‘Coveringates’ didn’t really work as a name, so the tunic aspect became the name. 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

IF THEY CAN’T MOVE, HOW DO THEY… (erm…) REPRODUCE?

Tunicates are broadly speaking asexual. Once a colony has become attached to corals or sponges, they are able to ‘bud’, ie to produce clones to join the colony. These are like tiny tadpoles and their first task is to settle and attach themselves to something suitable – for life – using a sticky secretion. Apparently they do this head first, then in effect turn themselves upside down as they develop the internal bits and pieces they need for adult life. The colony grows because (*speculation alert*) the most obvious place for the ‘tadpoles’ to take root is presumably in the immediate area they were formed.

 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

Some types of tunicate contain particular chemicals that are related to those used to combat some forms of cancer and a number of viruses. So they have a potential use in medical treatments, in particular in helping to repair tissue damage.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

Credits: all fabulous close-up shots by Melinda Riger / Grand Bahama Scuba; diagram from depts.washington.edu; magpie pickings with a particular mention of an article by Sara MacSorley

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

 

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS


Sand Dollar, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS

Echinoderms (Gr. ‘Hedgehog Skin’) comprise a large variety of sea creatures characterised (mostly) by radial symmetry. In a nutshell a creature with radial (as opposed to bilateral) symmetry can be divided into equal portions from the centre, like a cake. It has no left or right side and no definable front or back.  It is multidirectional from the centre, where the mouth is located. It obviously has a distinct upper side and an underside, but that has no bearing on this form of symmetry. 

Ten dollar Sand Dollar coin, Bahamas

Within the family of radially symmetrical animals, echinoderms (starfish, sand dollars and sea urchins) are unique in having five-point radial symmetry. These are the creatures you are most likely to come across in Abaco. There are two particular aspects of dollars and biscuits that merit a closer look (made more difficult by me stupidly taking photos of white things on a white background).

Sand Dollar Doves, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

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”.

The Sand Dollar Legend

A few years back, Senior Granddaughter was looking at some Abaco sand dollars I’d given her for her growing 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, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

Five white doves (in fact, the separated parts of the creature’s feeding apparatus)Sand Dollar Doves, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

Two broken pieces showing where the doves are centrally locatedSand Dollar Doves, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

A regrettably poor photo of a single doveSand Dollar Doves, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

The image below, from Pinterest, shows the ‘mouth’ with its dove-parts intact, in an arrangement called ‘Aristotle’s Lantern‘, a five-sided globular structure that supports the mouth and jaws of an echinoderm.

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. Senior GD (a most inquisitive girl) followed up on the doves research after discovering a box containing random stones and fossils. She found these two items:

Fossilised sea biscuitsPetrified / Fossilised Sea Biscuit (Keith Salvesen)

A closer look at the pair of rocksPetrified / Fossilised Sea Biscuit (Keith Salvesen)

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

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

Sea biscuits on the beach at Delphi – familiar white skeletons (‘tests’) but not yet fossilsSea Biscuits, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

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

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 more than 40 US States have State Fossils. Whatever next? State Bacteria? State Viruses?

Sea biscuit from Madagascar (OS)

SO HOW OLD MIGHT A PETRIFIED BISCUIT BE?

The fossil biscuits I have looked at, from Florida to Madagascar (see small image above), 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. This chart also helpfully helps avoid confusion with the Eon Era Period Epoch ordering.

geotimescale

You will find more echinoderm entertainment using this link to my fellow-blogger ‘Dear Kitty’ https://dearkitty1.wordpress.com/2007/01/01/big-hedgehog-small-sand-dollars-diving-schools/

All photos ‘in-house’ except the Delphi biscuits, Clare Latimer; & the single biscuit Rhonda Pearce; Sand Dollar poem on Postcard, Dexter Press; the Geochart was in my ‘useful chart photos’ folder but I can’t now find the source. I did try.

 

“GIFTS FROM THE SEA”: THE CHEROKEE SHELL MUSEUM


Cherokee Shell Museum, Abaco Bahamas (Keith Salvesen)

“GIFTS FROM THE SEA”: THE CHEROKEE SHELL MUSEUM

In the shadow of a tall pylon in the secluded settlement of Cherokee stands Abaco’s smallest museum. Make that one of the world’s smallest museums. As I mentioned after it opened last year, other contenders for the title include the MmuseumM in New York, housed in an elevator shaft (look through glass window + audio guide); a converted red telephone kiosk in Warley, Yorkshire UK dedicated to local history (one visitor at a time); and a tiny shed of 134 sq ft in Arizona featuring what might broadly be called ‘ephemera’, including a Beatles poster…

Cherokee Shell Museum, Abaco Bahamas (Keith Salvesen)

This tiny museum is dedicated to the shells of Abaco. It is almost certainly the smallest shell museum anywhere in the world (except maybe the one you kept in a small box under your bed when you were 10). 

Cherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Cinder Pinder

“Gifts from the Sea” is housed in the former 1950s telegraph office that ceased to operate in 1987 and had fallen into disrepair. Leased from BTC for a nominal rent, the little building was restored, and given a smart new roof and a complete makeover. It’s the perfect space for displaying a selection of the wonderful shells and corals to be found in Abaco waters.

Cherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Cinder Pinder

This community project is the vision and creation of Curator Lee Pinder. Derek Weatherford fitted cabinets for the exhibits, and artist Jo-Ann Bradley painted a interior Cherokee-themed mural as a fitting backdrop to the displays.

Cherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Cinder Pinder

The exhibition shows more than 200 shells, each catalogued with its Latin and common name, and clearly labelled in the display. Most were found locally; a few are from further afield. Some specimens are very rare. The collection will expand as people make shell donations to the museum. 

Cherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Abaconian

The building has a door at each end to give natural light and provide a ‘walk-through’ arrangement, which makes viewing in the confined space easier. Entry is free but there’s a glass jar for donations towards the upkeep of the museum. I’m guessing here, but I reckon donations made ‘outside the jar’ (so to speak) are very welcome too…

Museum Curator Lee PinderCherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Cinder Pinder

The opening ceremony took place on Easter Saturday 2017, when Cherokee resident Rev. Bateman Sands performed the official ribbon cutting ceremony preceded by a prayer at precisely 12 noon. As Jennifer Hudson in an Abaconian article pointed out, he was the ideal person for the task, having been “the first telegraph operator in Cherokee Sound, working in the little building using Morse code and in charge of the one and only telephone in the settlement until 1987 when the new BTC building was opened”.

Cherokee Shell Museum, Abaco Bahamas / Gifts from the Sea / Cinder Pinder

The shell museum is not left open all the time, but visitors are welcomed on weekend afternoons, and private tours can be arranged by calling either number shown below on the notice attached to the door.

Cherokee Shell Museum, Abaco Bahamas (Keith Salvesen)

To see a selection of the many types of Abaco shells, check out my shell page HERE

Sources and Photo Credits: Bradley Albury / Jennifer Hudson / Abaconian; Cindy James Pinder (shells, interior 2017); Keith Salvesen (exterior, 2018)

Cherokee Shell Museum, Abaco Bahamas (Keith Salvesen)

SEA BISCUITS: THEY REALLY DO CONTAIN DOVES – AND MORE!


Sea Biscuit Close-up, Abaco (Keith Salvesen)

SEA BISCUITS: THEY REALLY DO CONTAIN DOVES – AND MORE!

Recently I posed the question whether sea biscuits, like sand dollars contain ‘doves’. I had one in my hand, it rattled, I took a photograph through its ‘mouth hole’ and the question was answered. Biscuits do indeed contain doves – see HERE for details and comparisons with dollar doves.

Sea Biscuit 'Doves', Abaco (Keith Salvesen)

However, I spinelessly* failed to break open the biscuit to check out the contents more closely. I theorised that, because of the 5-way symmetry of these creatures, there would be 5 doves (which are in fact segmented mouth parts) in a biscuit exactly as with a dollar, and amiably challenged anyone to disprove it. [* biscuits and dollars are types of sea urchin – see what I did there?]

Dollar dove in close-up – one of 5 segmented mouth parts inside the ‘test’ (skeleton)Sand Dollar 'Doves', Abaco (Keith Salvesen)

Melissa Ann Guinness from Hope Town has a far more robust attitude to these things and, taking up the challenge, she heartlessly smashed open a sea biscuit from her collection to investigate further. I said I’d publish a correction if my theory was wrong. This is it – though in one arguable sense the theory holds good. It just didn’t go far enough…

Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

In the above picture you can see (a) 4 quarters of a sea biscuit skeleton (b) 10 demi-doves (rather than 5 whole doves) and (c) a small mummified 5-limbed brittle star that was presumably in the creature’s digestive system when it died.

10 ‘demi-doves’  (or, when assembled, 5 doves that (unlike sand dollars) are in 2 parts
Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

Complete doves

Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness) Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness) Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

The final reconstruction – 5 doves and a bonus brittle star

Sea Biscuit 'Doves', Abaco (Keith Salvesen)

Photo Credits: Keith Salvesen (1, 2, 3, 10); Melissa Ann Guinness (4, 5, 6, ,7 ,8 ,9)

FLORAL CORAL: REEF GARDENS IN THE BAHAMAS


Reef Corals, Bahamas (Melinda Riger / G B Scuba)

FLORAL CORAL: REEF GARDENS IN THE BAHAMAS

Like many of the blues musicians who covered Robert Johnson’s originals, we got ramblin’ on our minds. Specifically to ‘Delphi East’ in Ireland, thus stupidly exchanging 82F sunshine in southern UK for 46F rain in the Emerald Isle. Good for the fishing, if nothing else… So (always remembering that corals are actually creatures and not plants) here’s a bouquet of coral to be going on with until we next meet with wifi!

Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)

OPTIONAL MUSICAL RAMBLING

Robert Johnson’s output – a meagre 29 songs in all – formed the bedrock for later bluesmen and the blues / rock crossovers that followed. They mined Johnson’s talent and formed their own new material from it. Here’s the original – you’ve probably heard it or variations of it with different names, a thousand times – some good, some bad, most so-so. 

Entire coral pot pourri by Melinda Riger / Grand Bahama Scuba

SEA BISCUITS: DO THEY REALLY CONTAIN DOVES?


Sea Biscuits, Delphi, Abaco (Clare Latimer)

Sea Biscuits on the Beach, Delphi, Abaco Bahamas

SEA BISCUITS: DO THEY REALLY CONTAIN DOVES?

A couple of years ago I wrote a post called ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS. It dealt with the… fact? rumour? old wive’s tale?… that within each sand dollar test (i.e. the white skeleton) are hidden 5 ‘doves’. You can hear them rattling inside if you shake the dollar… 

Sand Dollar Doves (Keith Salvesen) 6

Sand Dollar from Abaco containing 5 miniature white doves…

I investigated the theory with senior granddaughter, and we broke a sand dollar in half. And as you can see, the answer was undoubtedly yes – there were 5 tiny white doves, thus fulfilling the prediction of the famous ‘Sand Dollar’ poem that contains the lines  “Now break the centre open And here you will release The five white doves awaiting To spread good will and peace”.

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

A single dove, a picture of dovelinessSand Dollar Doves (Keith Salvesen) 3

I never thought to extend the experiment to sea biscuits, another object prized by beachcombers. All that changed last month when I picked up a sea biscuit and found that it, too, rattled.

A rattling good sea biscuit

So I turned it over to take a closer look at the underside. And there, unmistakably, was the source of the rattle – some kind of internal arrangement inside the feeding  hole (let us not pause overlong to consider the purpose of the other hole). But it wasn’t conclusively a dove.

So I shook it around a bit (sorry, doves) and zoomed in. And there was a small white columbine-type contraption remarkably similar to those found in the dollar dove. And no, I did not smash open the sea biscuit (it wasn’t actually mine). And no, I didn’t doubt any longer that sea biscuits also contain doves.

SO WILL THERE BE 5 DOVES, LIKE WITH THE DOLLARS?

I predict there will also be five. Both dollars and biscuits have ‘five-way symmetry’ (look on the topside of a biscuit or dollar to see how); and so the mouth (from which the ‘doves’ derive) will have a single part for each of the five sectors, all linked. 

If anyone would like to smash up one of their precious beach finds and test the theory, please feel free. Prove me wrong… and I’ll publish a correction! [Photo please…]

All photos Keith Salvesen except Header, Clare Latimer at Delphi

SEA GLASS TREASURES & TWO ISLAND CHICKS…


Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

SEA GLASS TREASURES & TWO ISLAND CHICKS…

It’s time to shine the Rolling Harbour spotlight on sea glass, a neglected (by me) topic recently . Everyone loves it (don’t they?), and there’s always a bit of excitement in finding a pretty piece of cloudy glass gleaming in the sand on the beach. Just look at that colour. Might it be rare? How old could it be? Should I pick it up or leave it for someone else to enjoy? 

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

Collecting sea glass is one of the pleasures of a walk on the beach. Or maybe it’s the motivation for the walk. For some, it is an opportunity to turn what the sea throws onto the beach into something decorative. Abaco is home to some excellent jewellery** makers who specialise in using locally found materials to make beautiful things. These sometimes incorporate a mix of sea glass, pebbles, and small shells.

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

In Hopetown on Elbow Cay, Hilary Thompson and Erika Feszt Russell do just that. Trading under the name ‘Two Island Chicks’, they use sea glass in many of their creations, some examples of which are displayed here. As you’ll see, they also apply their creativity to showing their jewellery attractively. 

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

The collected glass has to be sorted into the various colours. Most are quite common (white, green, brown), some are uncommon (eg cobalt blue), and just a few that are very rare – and possibly valuable (red, orange) – see charts below.

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

The charts below give a general overview of the comparative rarity of various sea glass colours, their sources, and the chances of making a rare find. Of course, these are mainstream colours; there are many other in-between hues and shades.

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

Can you spot the most unusual piece of sea glass here?Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks) Sea Glass & Jewellery, Abaco, Bahamas (Two Island Chicks)

RELATED POSTS

BEACHCOMBING FOR SEA GLASS with Kasia

BOOKCOMBING: SEA GLASS BOOKS (4 books compared)

ABACO ARTS & CRAFTS (with drop-down menus)

** Yeah yeah, I hear you. Jewellery? How English is that? Please mentally substitute ‘jewelry’ throughout. Maybe the same for colour / color. This is a bi-lingual area.

THE TWO ISLAND CHICKS

Credits: Hilary and Erika for all the photos; as for the sea glass charts (1) West Coast Sea Glass 2006 (as found in a number of online sources); (2) Origin unknown (ditto re online sources)