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 pale 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 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 pairPetrified 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 around 40 States have State Fossils.

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 eras – from the oldest, Jurassic, Eocene and Pleistocene. 

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

“CLEANING UP”: HOW TINY REEF FISH HELP LARGE FISH


Black Grouper - Arnold - Cleaning Station - Neon Gobies ©Melinda Riger @ G B Scuba copy

“CLEANING UP”: HOW TINY REEF FISH HELP LARGE FISH

A while ago now, I wrote a detailed post about so-called fish ‘cleaning stations’ – the special spots on the reef where large fish can go to have small fish buff up their scales and floss their teeth. You can read all about it HERE.

I have accumulated a number of new photos from expert scuba diver and underwater photographer Melinda Riger that demonstrate this phenomenon. A big fish with a normally voracious appetite will patiently wait while gobies and other small fry go about their work. This often involves actually entering the mouth of the (as it must seem to them) monster to pick the insides and the teeth clean. There is an extraordinary understanding and trust between the species that means during the operation, the little fish are perfectly safe. Here are some examples, of which the very recent header image of a grouper named Arnold is quite outstanding.

Tiger Grouper + cleaner goby ©Melinda Riger @ G B Scuba copyGrouper, Black at cleaning station ©Melinda Riger @G B Scuba copy Tiger Grouper at cleaning station ©Melinda Riger @ G B Scuba copy Tiger Grouper being cleaned ©Melinda Riger @G B Scuba copy

It is not just gobies that attend the fish. Various species of shrimp also volunteer for the job.

Tiger Grouper with cleaning shrimps and goby ©Melinda Riger @ G B Scuba copy Grouper being cleaned ©Melinda Riger @ GB Scuba copy

Groupers are not the only species to make use of cleaning stations. Here is a dog snapper at the same cleaning station as the grouper in the header image. Below is a stingray being attended to.

Dog Snapper at cleaning station ©Melinda Riger @ G B Scuba copy

Southern Stingray with cleaning gobiesStingray, Southern with cleaning gobies ©Melinda Riger @ G B Scuba copy

GRAMMATICAL DIGRESSION There is this ‘thing’ about the correct use of the words ‘fish’ and ‘fishes’ in the plural form. The basic principle is simple: ‘fish’ where you are referring to several of the same species; ‘fishes’ where more than one species is involved. I don’t care. My policy is to use ‘fish’ as the plural on all occasions, so I don’t have to think about it. Pedants, look away now.

RELATED POSTS

TAKEN TO THE CLEANERS

BANDED CORAL (‘CLEANER’) SHRIMP

TIGER GROUPER

BLACK GROUPER

All photos: Melinda Riger, Grand Bahama Scuba

THE ‘THRUSH’ THAT ISN’T: NORTHERN WATERTHRUSH ON ABACO


Northern Waterthrush.Bahama Palm Shores.Abaco.3.Tom Sheley

THE ‘THRUSH’ THAT ISN’T: NORTHERN WATERTHRUSH ON ABACO

The pretty thrush-like warbler Northern Waterthrush Parkesia noveboracensis is a common winter resident on Abaco. Despite the name it’s not a real thrush, but it is larger than most of the compact winter warblers that heed the the migratory instinct that “It’s Better in the Bahamas” and make Abaco their overwintering habitat.

Northern Waterthrush.Bahama Palm Shores.Abaco.1.Tom Sheley

HOW CAN YOU TELL SIMILAR PLUMAGED THRUSHES FROM THESE GUYS?

The simplest rule of thumb is that true thrushes have spotted or speckled chests; whereas waterthrushes have streaked chests. That, and the fact that similar thrush species are generally larger. A number of true thrushes are recorded for Abaco, many quite similar to the waterthrush; but the speckled vs spotted distinction should be your guide. If a sighting is momentary or in bad light, it’s anyone’s guess…

Northern Waterthrush, Abaco (Becky Marvil)

northern_waterthrush_rangemap(1)

APART FROM THRUSHES, ANY OTHER BIRDS I MIGHT CONFUSE IT WITH?

There’s another far less commonly found waterthrush that also overwinters on Abaco – the closely-related Louisiana waterthrush Parkesia motacilla. I have no Abaco photos of one – it really is quite rare – so I’ve had to borrow an open source one. The Cornell Lab explains the differences between the two waterthrushes thus: “Northern usually has stripes on throat, a slightly smaller bill, a thinner and off-white or cream eyestripe that does not extend as far onto the nape, less pink legs, and a more yellowish wash on the underparts”. Maybe one can generalise that the northern is overall a yellower bird, and its legs are more brown than pink.

Lousiana waterthrush – rarer on Abaco than the northern but a potential source of confusionLouisiana_Waterthrush_(Parkesia_motacilla) Magnus Manske : Wiki

WHAT’S THAT POSH TAXONOMIC NAME ALL ABOUT, THEN?

The Mr Parkes in question was Kenneth Carroll Parkes (1922 – 2007), an American ornithologist and Chief Curator at the Carnegie Museum of Natural History, Pittsburgh. The noveboracencis part simply means ‘from New York’ in Latin (novum – new; Eboracum – York); and the -ensis is a common suffix meaning ‘from’. Mr Parkes’s bird from New York.

Kenneth Carrol ParkesMr Parkes

Northern Waterthrush, Abaco (Bruce Hallett)
Both species have similar habits. For example, on the ground, they tend to walk rather than hop, ‘bobbing’ their butts (technical term) as they go. They forage on the ground for insects, snails and small mollusks etc.
  
Northern Waterthrush, Abaco 1 (Gerlinde Taurer)
I’m not a huge fan of attempts at phonetic renditions of bird calls – the ‘Did you have a nice day today dear?’ and the ‘I’d like a very big Kalik please’ and so on. But for what it is worth, the song of the northern waterthrush has been interpreted as “a loud swee swee chit chit weedleoo”.  This is what is sounds like in real life. Go figure.
Northern Waterthrush, Abaco 2 (Gerlinde Taurer).jpg

Credits: Tom Sheley (1, 2, 8); Becky Marvil (3); Magnus Manske (4); Bruce Hallett (5); Gerlinde Taurer (6, 7); Richard E Webster at Xeno-Canto for the song clip

Northern Waterthrush.Bahama Palm Shores.Abaco.2.Tom Sheley

“CALLING ELVIS” (THE SQUIRRELFISH, NOT THE MAN)


Squirrelfish Elvis ©Melinda Riger @ G B Scuba

“CALLING ELVIS” (THE SQUIRRELFISH, NOT THE MAN)

How proud The King would be to know that his name lives on in the form of an attractive though sadly unmusical Bahamian squirrelfish. This little guy is at least 5 years old. What is more, he has lived at the same address all that time, defending it against usurpers and protecting himself from predators in its safe depths. Here is the loveable little Elvis photographed at home between 2012 and 2016 (header image), the master of his own underwater Graceland…

Squirrelfish (%22Elvis%22) ©Melinda Riger GB ScubaElvis the Squirrelfish ©Melinda Riger GB Scuba Squirrelfish ©Melinda Riger @ GB Scuba Squirrelfish ©Melinda Riger @ G B Scuba

The reason that Elvis has such large eyes is that these fish are mostly nocturnal, and (apart from when Melinda is out with her camera), he and his friends spend most of the day either at home, or in crevices, small rock caves, or under ledges. However, here are a couple of shots of Elvis out and about, enjoying some quality time among the corals.

Squirrelfish (Elvis) ©Melinda Riger @ Grand Bahama ScubaSquirrel Fish ©Melinda Riger @ G B Scuba

ROLLING HARBOUR MUSICAL DIGRESSION

I so wanted to add a specific Elvis catalogue ‘Musical Digression’, but try as I might, there is no title in The King’s discography that has any potential for finny nuance or piscine pun value. However, here’s a track from the now tragically unhip Dire Straits on their follow-up album to the phenomenal ‘Brothers-in-Arms’, the much under-rated ‘On Every Street’. I give you… Calling Elvis, a song that cunningly contains as many titles of Presley hits as anyone could ever wish for.

All images: Melinda Riger at Grand Bahama Scuba; cartoon from a sequence on the excellent BCCR Defenses page – learn about camouflage and other fishy self-protection techniques

Nocturnal squirrelfish checks out a parrotfish’s sleeping arrangementscamoSquirrWparrot01

SMALL ABACO BIRDS TO MAKE THINGS BETTER


Blue-gray Gnatcatcher, Abaco 1 (Keith Salvesen)

SMALL ABACO BIRDS TO MAKE THINGS BETTER

Bad day. I know about random outage outrage and so on, but really… The router died, unmourned. Bought another. Wasted 2 hours trying to make it work. Turns out to be ‘defective’, which is to say broken. Or another B word. Bought another. Almost lost the will to live. I have the briefest window in which to check emails etc before it, too, checks out of the Mac Hotel. The ONLY SOLUTION (apart from Kalik in copious quantities, sadly not available where I am right now), is to look at some pretty birds taken in the gardens round the Delphi Club. Mmmmm. Feeling better now. Deep breaths… and… relax…

Bananaquit, Abaco 1 (Keith Salvesen)La Sagra flycatcher, Abaco 1 (RH)Cuban Emerald, Abaco (Keith Salvesen)Yellow-throated Warbler, Abaco (RH)

All pics by a rather stroppy RH

STOP PRESS Exactly 24 hours after excitedly unwrapping the (second) new router, after a convoluted and Kafkaesque series of phone calls to various techie centres, headily mixed with wine, beer, tears and tantrums, I combined some of the info from each and miraculously the recalcitrant beast sprang to life. For how long, though? Router advice given: $100 ph + exes

GULL-BILLED TERNS ON ABACO


Gull-billed Tern, Abaco (Alex Hughes) 01

GULL-BILLED TERNS ON ABACO

The gull-billed tern Gelochelidon nilotica had a name upgrade from Sterna nilotica some years ago, and was awarded the honour of its own genus. Let’s be clear at the outset: there’s no such thing as a tern-billed gull. Which slightly lessens the scope for species confusion. 

Gull-billed Tern, Abaco (Alex Hughes) 04

For those (me) who need a reminder about the whole family / genus / species taxonomic maze, here is a reminder. The example used is man. Or stickman, anyway.3958555126_4f85d9fa5b

Gull-billed Tern, Abaco (Alex Hughes) 05

There are 12 species of tern recorded for Abaco. Only one, the royal tern, is a permanent resident. There is one winter resident, the Forster’s tern and there a 6 summer resident terns of varying degrees of commonness. The other four are transient or vagrant, and probably not worth making a special trip to Abaco to find. The GBT is designated SB3, a summer breeding resident that is generally uncommon, though might be more common in particular areas.

TERN TABLE**Tern Species Abaco**I know! Too tempting…

gull-billed-tern

Gull-billed Tern, Abaco (Alex Hughes) 11

The bird gets its name from it short, thick gull-like bill. It’s quite large in tern terms, with a wingspan that may reach 3 foot. They lose their smart black caps in winter.

Gull-billed Tern, Abaco (Alex Hughes) 03

There are 6 species of GBT worldwide, and it is found in every continent. While many terns plunge-dive for fish, the GBT mostly feeds on insects in flight, and will also go after birds eggs and chicks. Small mammals and amphibians are also on the menu. The header image shows a GBT with a small crab. I imagine they must eat fish. Surely they do? But I have looked at dozens of images online to find one noshing on a fish, with no success. Does anyone have a ‘caught-in-the-act’ photo?

Gull-billed Tern, Abaco (Alex Hughes) 06Gull-billed Tern, Abaco (Alex Hughes) 02

All photos were taken by Alex Hughes, a contributor to “THE BIRDS OF ABACO”, when he spent some time on Abaco a while back in connection with the conservation of the Abaco Parrot and the preservation of the habitat integrity of their nesting area in the Abaco National Park

Gull-billed Tern, Abaco (Alex Hughes) 12

CHEROKEE LONG DOCK: ABACO LANDMARKS (1)


Cherokee Long Dock Aerial (David Rees)

CHEROKEE LONG DOCK: ABACO LANDMARKS (1)

Cherokee Long Dock has a significant claim to prominence on an Island that has, with its Cays, a good few docks to admire. The impressive 770 foot wooden dock is the longest wooden dock in the Commonwealth of the Bahamas, as its plaque proudly proclaims. The waters of Cherokee Sound are very shallow in places, and as the tides retreat, so sandbanks appear and the rest is barely covered by the sea. Hence the need arose for a very long dock to serve the very small community of Cherokee.

Cherokee Long Dock, Abaco, Bahamas (Larry Towning 1)Cherokee Long Dock, Abaco, Bahamas (Larry Towning 2)

Before the roads were built – in relatively recent memory – Cherokee was an isolated settlement. There was a shortcut connection by boat to a now-abandoned dock at the nearest community, Casuarina, across the Sound. However, non-tide-dependent access from the open sea was vital for supply boats and mail boats. Access to the sea was needed by the fishermen.

Cherokee Long Dock 4 (Amanda Diedrick) Cherokee Long Dock 2a (Amanda Diedrick) Cherokee Long Dock 1 (Amanda Diedrieck) jpg

The plaque documents the history of the dock, the damage inflicted by hurricanes, and the ‘countless hours of labour’ by local people- ‘men, women and children’ – to preserve the dock.Cherokee Long Dock: the plaque (Amanda Diedrick)

Royal terns and other seabirds use the dock to rest; and as a safe place from which to fishCherokee Long Dock (Velma Knowles)

Cherokee Long Dock 3 (Amanda Diedrieck)IMG_3013

Photo credits: David Rees and his wonderful drone (header); Larry Towning (2, 3); Amanda Diedrick (4, 5, 6, 7, 9); Velma Knowles (8); last image from a FB friend with thanks and many apologies – I’ve lost my note of who took it…  to be added if possible; short vid from Youtube.