WTF? (WHAT’S THAT FISH): FLYING GURNARD

November 21, 2025 by Rolling Harbour

WTF? (WHAT’S THAT FISH) 10: FLYING GURNARD

Imagine that you are swimming along resplendent in your snorkeling gear (me) – or in scuba gear for the advanced swimmer (you). There, below you, camouflaged against the sea bottom is a fish. A strange-shaped brown sort of creature with odd side fins. As it progresses over the gravelly sand, your immediate reaction is ‘What the f…?’ Its fins seem to be turning into… wings. Like this:

Flying Gurnard (Adam Rees / Scuba Works)

Yes, it’s a flying gurnard. Unlike flying fish, it can’t actually fly through the air. But once its wings are fully spread, it certainly looks as though it could.

Flying Gurnard (Adam Rees / Scuba Works)

WHAT’S THE POINT OF THE WINGS IF THE THING CAN’T FLY?

This gurnard species usually gets around using its ventral fins as ‘legs’, with the pectoral fins (‘wings’) close to the body. There seem to be several possible reasons for possessing the ‘sudden-deployment-of-flashy-wings’ superpower.

It surprises and deters predators by movement, turning prospective prey into an apparently different creature
Bright or lurid colouring may be a deterrent warning of a foul-tasting or poisonous species (APOSEMATISM)
A creature may actually be harmless and even tasty (as here) but may appear to be unpalateable or poisonous (BATESIAN MIMICRY)
In any event, the wings enable the fish to take off from the sea bottom and travel faster by ‘flying’ thought the water to escape a predator

Dactylopterus_volitans Flying Gurnard (cralize wiki)

I had a quick look to see how scientists in history had depicted this extraordinary fish. The earliest illustration I could find was taken from “Allgemeine Naturgeschichte der Fische (General natural history of fishes),” a 12-volume encyclopedia by author/illustrator Marcus Elieser Bloch (1723-1799), which described all fish species then known to science (and 267 previously unknown) (© AMNHD. Finnin) sourced from ‘Hyperallergic’

Flying Gurnard

Here’s a short video of a flying gurnard on the move, from ‘Sia Big Fish’

Credits: All main images Adam Rees / Scuba Works with many thanks as ever, except final one ‘cralize wiki’; Hyperallergic for the historic image; Sia Big Fish for the video

Rolling Harbour / Keith Salvesen (V2)

OCTOPUS’S GARDEN (TAKE 9) IN THE BAHAMAS

October 8, 2025 by Rolling Harbour

WORLD OCTOPUS DAY

Continue reading →

BRITTLE STARS: PRIMITIVE YET INCREDIBLY COMPLEX STARFISH

September 30, 2025 by Rolling Harbour

BRITTLE STARS: PRIMITIVE YET INCREDIBLY COMPLEX STARFISH

BRITTLE STARS are closely related to starfish, and in particular to Basket Stars. They are commonly known as “serpent stars”, having 5 long, thin arms that may grow as long as 2 feet long. There are lots of different types of brittle star – at least 2000 – and they are found in every ocean on earth from the poles to the tropics. In Bahamian waters they a commonly found living on reefs.

Although these creatures look primitive, their structure, nervous systems, respiratory systems, digestive systems, sex lives and transportation methods are incredibly complex. Take it from me – I’ve just read about it all. So I’ve decided to pick a few aspects of these creatures to highlight rather than discuss the minutiae of their ossicles (tiny bones), madroporites (a sort of water filter / pressure balancer) and viscera.

You are most likely to see Brittle Stars clinging to coral or sponges

A DOZEN BRITTLE STAR FACTS TO PLAY WITH

The star has no eyes and no sense organs as we know them, but can detect light chemically; and (why would they need this?) sense smell through their ‘feet’… [Not a superpower I would prize, but still]
The mouth is on the underside of the central disc (‘body’) of 5 segments, each with a toothed jaw
The mouth is used both for ingestion and, putting it delicately, egestion. [Nor that superpower]
Stars eat tiny organisms suspended in the water or mini-worms, gathering them with their arms
If I have understood this, they breathe through their armpits, and can excrete from here also
The arms fit the main part with ball and socket joints, and are flexible in all directions
The genitals seem to be located in or between the armpits (lucky we are not descended from stars)
Stars readily regenerate lost arms until they lose the 5th – then they are in real trouble
This enables them to shed an arm in a predator attack, like a lizard its tail
Trials indicate that a jettisoned arm cannot regenerate from itself
They use only 4 arms to move along, with the fifth ‘steering’ out in front or trailing behind
Brittle Stars are inedible but non-toxic

Often, brittle stars will cling on inside a sponge

I quite liked this infographic from a source new to me, ‘Weird ‘n’ Wild Creatures Wikia’

Here is a great video from Neptune Canada of a brittle star fight on the ocean floor over the remains of a shrimp. If you watch the ones joining the fight, you will clearly see the locomotion method described above, with one limb pathfinding and the other four ‘walking’.

I’m not renowned for extreme sensitivity, so I feel no shame in showing mating brittle stars, courtesy of Channel Banks. It’s not exactly Lady Chatterley and Mellors, but the entwined arms are rather romantic, no?

Credits: all wonderful photos by Melinda Riger of Grand Bahama Scuba; BS infographic and viddys as credited

WORLD DOLPHIN DAY 2025 and BMMRO NEWS

September 14, 2025 by Rolling Harbour

WORLD DOLPHIN DAY 2025

September 12th is the day chosen by Sea Shepherd to raise awareness and promote the conservation of dolphins. It was established on the one-year anniversary of the killing of 1,428 Atlantic white-sided dolphins in the Faroe Islands, which was the largest single slaughter of cetaceans in history.

As many will know, the marine mammals of the Bahamas – whales, dolphins and manatees – are researched and protected by the Bahamas Marine Mammal Research Organisation. It was established more than 20 years ago by Diane Claridge and Charlotte Dunn. Based for many years in Sandy Point, Abaco, the organisation has recently extended its operations to an office in Marsh Harbour.

BMMRO has a wide remit in marine mammal research and education. Young children are given an opportunity to learn what lies beyond the seashore. Older children have opportunities for combining learning with fun at the summer Whale Camps. There are learning groups and talks, and all schools are welcome to participate.

Plans in progress include establishing Whale Camps on other islands, such as Long Island and Eleuthera. There has also been outreach to Exuma and the Berry Islands.

At a more advanced level, BMMRO provides outstanding opportunities for older students to increase their knowledge and skills, to take these to higher education, and to prepare them for the life of a marine mammal researcher.

BMMRO has recently produced a comprehensive Field Guide featuring all 27 marine mammal species found in Bahamian waters. These give a great deal of information and are readily available.

You can find out more about the nature and scope of the work carried out by BMMRO HERE . The speed of the development of sundry critical threats to the world’s oceans and their denizens has been astonishing. It is now irreversible. Fortunately the number of ocean research and protection organisations has increased significantly as the situation worsens. Please consider making a donation to support the work of BMMRO, or (for those elsewhere in the world), to the marine mammal organisation in your area.

LEAD SCIENTISTS: Diane and Charlotte – pioneer researchers in the Bahamas over 4 decades

All Photos: @BMMRO

LINKS: BMMRO . MM SIGHTINGS . WHALE CAMP 2025 . ROLLING HARBOUR

Credits: BMMRO . Rolling Harbour / Keith Salvesen

CRAB RUN – THE MOVIE

August 14, 2025 by Rolling Harbour

ROLLING HARBOUR MOVIES PROUDLY PRESENTS

CRAB RUN – THE MOVIE

LOCATION: DELPHI CLUB BEACH, ABACO

(Music: Chet Atkins ‘Yakkety Axe’, aka The Benny Hill Show Theme)

Found in old folder for this newish blog in 2012, when I featured plenty of tosh just for fun

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS

June 29, 2025 by Rolling Harbour

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS

FLAMINGO TONGUE SNAILS Cyphoma gibbous are small marine gastropod molluscs related to cowries. The living animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the so-called ‘mantle’. The shell itself is usually pale, and characterised by a thick ridge round the middle. Whether alive or as shells, they are gratifyingly easy to identify. These snails live in the tropical waters of the Caribbean and the wider western Atlantic.

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

THE IMPORTANCE OF CORAL

Flamingo tongue snails feed by browsing on soft corals. Often, they will leave tracks behind them on the coral stems as they forage (see image below). But corals are not only food – they provide the ideal sites for the creature’s breeding cycle.

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 protectively 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 the snail’s feeding preference is generally not harmful to the coral.

The principal purpose of the patterned mantle of tissue over the shell is to act as the creature’s breathing apparatus. The tissue absorbs oxygen and releases carbon dioxide. As it has been (unkindly?) described, the mantle is “basically their lungs, stretched out over their rather boring-looking shell”. There’s more to them than that!

THREATS AND DEFENCE

The species, once common, is becoming rarer. The natural predators include hogfish, pufferfish and spiny lobsters, though the spotted mantle provides some defence by being (a) startling in appearance and (b) on closer inspection by a predator, rather unpalatable. Gorgonian corals contain natural toxins, and instead of secreting these after feeding, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many animal species.

MANKIND’S CONTRIBUTION

It comes as little surprise to learn that man is considered to be the greatest menace to these little creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the actual shell of the animal, collect up a whole bunch from the reef, and in due course are left with… dead snails and their allegedly dull shells Don’t be a collector; be a protector…

The photos below are of nude flamingo tongue shells. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. I still do. You decide!

Image Credits: Melinda Rogers / Dive Abaco; Keith Salvesen / Rolling Harbour; Wiki Leopard

ELKHORN CORAL . REEF LIFE . ABACO . BAHAMAS

June 20, 2025 by Rolling Harbour

ELKHORN CORAL (Acropora palmata) is a widespread reef coral, an unmistakeable species with large branches that resemble elk antlers. The dense growths create an ideal shady habitat for many reef creatures. These include reef fishes of all shapes and sizes, lobsters, shrimps and many more besides. Elkhorn and similar larger corals are essential for the wellbeing both of the reef itself and also its denizens. These creatures in turn benefit the corals and help keep them in a healthy state.

Examples of fish species vital for healthy corals include several types of PARROTFISH, the colourful and voracious herbivores that spend much of their time eating algae off the coral reefs using their beak-like teeth. This algal diet is digested, and the remains excreted as sand. Tread with care on your favourite beach; in part at least, it will consist of parrotfish poop.

Other vital reef species living in the shelter of elkhorn and other corals are the CLEANERS, little fish and shrimps that cater for the wellbeing and grooming of large and even predatory fishes. Gobies, wrasse, Pedersen shrimps and many others pick dead skin and parasites from the ‘client’ fish including their gills, and even from between the teeth of predators. This service is an excellent example of MUTUALISM, a symbiotic relationship in which both parties benefit: close grooming in return for rich pickings of food.

VULNERABILITY TO CLIMATE CRISIS

Formally abundant, over the course of just a couple of decades elkhorn coral (along with all reef life) has been massively affected by climate change. We can all pinpoint the species responsible for much of the habitat decline and destruction, and the primary factors involved. In addition, global changes in weather patterns result in major storms that are rapidly increasing in both frequency and intensity worldwide.

Physical damage to corals may seriously impact on reproductive success: elkhorn coral is no exception. The effects of a reduction of reef fertility are compounded by the fact that natural recovery is in any case inevitably a slow process. The worse the problem gets, the harder it becomes even to survive, let alone recover, let alone increase.

HOW DOES ELKHORN CORAL REPRODUCE?

There are two types of reproduction, which one might call asexual and sexual:

Elkhorn coral reproduction occurs when a branch breaks off and attaches to the substrate, forming a the start of a new colony. This process is known as Fragmentation and accounts for roughly half of coral spread. Considerable success is being achieved now with many coral species by in effect farming fragments and cloning colonies (see Reef Rescue Network’s coral nurseries)
Sexual reproduction occurs once a year in August or September, when coral colonies release millions of gametes by Broadcast Spawning

All brilliant photos: Melinda Rogers, with thanks as ever for use permission

FAIRY BASSLET (‘MIND YOUR GRAMMA’): BAHAMAS REEF FISH

May 14, 2025 by Rolling Harbour

FAIRY BASSLET (‘MIND YOUR GRAMMA’): BAHAMAS REEF FISH (33)

The Fairy Basslet is a tiny brightly-coloured fish with a pretentious alternative name. It is otherwise known as the Royal Gramma (Gramma loreto). These fish are found in the coral reefs of the (sub)tropical western Atlantic. They are also found in aquariums anywhere you like, being small, bright, placid and generally good-natured.

Conveniently, the basslet is unlikely to be confused with any other species. Its striking two-tone colour scheme of purple and yellow is hard to miss. The purple front half (which is presumably where the ‘royal’ comes from, being a regal or imperial colour) may also be violet or even blue in some fish and / or in some light conditions. Another identification pointer is a black spot on the dorsal fin.

You’ll notice that the basslet above appears to be upside down. Which is because it is – this isn’t an inadvertent photo-flip. These little fish tend to orientate themselves to be parallel with the closest surface. This leads to them happily swimming upside down, or aligning vertically. As one article I read says severely, “this behaviour is not to be mistaken for illness”.

Fairy basslets / royal grammas are also CLEANER FISH. They pick parasites and dead skin off larger fish that visit so-called cleaning stations to be attended to by tiny fish and cleaner shrimps. The basslets also their customer’s gills and even their teeth. The deal is that, in return, the large fish do not eat the cleaners, even the snack-sized ones rootling around inside their mouths.

MUTUALISM

The relationship is a good example of mutualism, a type of symbiotic relationship where both species involved benefit from their interactions. Think also of cattle egrets and cows.

WHAT ABOUT BREEDING?

I really can’t improve on this rather touching description from Wiki:

“The male will build the nest among rocks using pieces of algae. The male will then lead the female to the nest, where she will deposit 20-100 eggs in the nest. During the breeding period, this behaviour is repeated almost every day for a month or longer. The eggs are equipped with small protuberances over the surface with tiny threads extending from them which hold onto the algae of the nest and keep the eggs in place. The eggs will hatch in five to seven days, normally in the evening…”

HOW COME THE NAME ‘GRAMMA LORETO’?

This official name became a brainworm with me after I started this post. I had to check it out. The ‘Gramma’ part simply denotes a member of the genus of fishes in the family Grammatidae.

The Loreto part is more mysterious. It is an an ancient town in Italy; and the name of several British schools, including – almost too good to be true – a school called Loreto Grammar. But it was also the name of Señorita Loreto Martínez, who caught the ‘type specimen’ while fishing in the bay at Matanzas, Cuba.

MISC

I failed to be able to resist finding out whether any country of the world has a purple and yellow flag. The answer is, no. However I am delighted to be able to report that the flag of the Independent Party of Uruguay is basslet-coloured.

Credits: all fantastic photos by Melinda Riger of Grand Bahama Scuba; magpie pickings of an unacademic sort for facts and speculation

‘TELLIN TIME’ – RISE AND SHINE: ABACO SEASHELLS

April 16, 2025 by Rolling Harbour

‘TELLIN TIME’ – RISE AND SHINE: ABACO SEASHELLS

SUNRISE TELLINS Tellina Radiata

These very pretty shells, with their striking pink radials, are sometimes known as ‘rose-petal shells’. They are always tempting to pick up from the sand. The ‘hinges’ (muscles) are very delicate, however, and with many of these shells that wash up on the beach the two halves have separated naturally.

Sunrise tellins are not uncommon, and make good beachcombing trophies They can grow up to about 7 cms / 2.75 inches, and the colouring is very varied, both outside and inside.

TELLIN: THE TRUTH

The occupant of these nice shells is a type of very small clam. They live on the sea-floor, often buried in the sand and with the lid (mostly) shut. When they die (or their shells are bored into by a predator and they are eaten) the shells eventually wash up empty on the beach. There’s not much more to say about them – they perform no tricks and are believed to have vanilla sex lives. Other small clams are quite inventive, doing backflips and copulating with enthusiasm.

Inside Story… not much to tell except (a) very pretty & (b) possible predator bore-hole top right

WHAT ELSE IS THERE TO KNOW ABOUT THEM?

These clamlets have 5 tiny teeth to chew up their staple diet, mainly plant material
These include one ‘strong’ tooth and one ‘weak’ one, though it isn’t clear why. How someone found this fact out remains a mystery
Tellins are native to the Caribbean and north as far as Florida
They live mainly in quite shallow water, but have been found as deep as 60 foot
They have no particular rarity value, and are used for marine-based crafting.

TELLIN LAW

You know those lovely tellins you collected during your holiday and took back home to your loved ones? You did take them, didn’t you? You may have committed a crime! In the Bahamas there is no specific prohibition on the removal of tellin shells, certainly not for personal use… but the general rule – law, even – seems to be “in most countries it is illegal to bring back these shells from holidays”.

Linnaean Examples

As ever, the very excellent Bahamas Philatelic Bureau has covered seashells along with all the other wildlife / natural history stamp sets they have produced regularly over the years. The sunrise tellin was featured in 1995. You can find more – much more – on my PHILATELY page.

All photos Keith Salvesen / Rolling Harbour; Rhonda Pearce, O/S Linnean Poster, O/S BPB stamp

WTF? (WHAT’S THAT FISH?): ARROW CRABS

March 23, 2025 by Rolling Harbour

WTF? (WHAT’S THAT FISH?): ARROW CRABS

The WTF? series is dedicated to the wilder, less conventionally fish-shaped side of reef life – those creatures that you may come across, blink into your face-mask, and silently mouth the words ‘What’s That Fish?’ (that’s what it looks like you are saying, anyway).

Let’s meet some Arrow Crabs Stenorhynchus seticornis, one of the very few creatures surely to have a triangular body plus a huge pointy nose (rostrum), supported on long skinny legs. To which add, they wear tiny blue gloves on their two front claws.

These crabs are coral reef dwellers and mostly stay concealed during the day. Their body is protected by a carapace, and the rostrum has serrated edges like a tiny rasp or file. I haven’t found a definitive reason for this gadget, but I suspect it is more for probing than for piercing or fighting.

There’s a considerable colour variation among these crabs, as these images show. The body may even have blue iridescent lines (#2, above). And those claws may be any of 50 shades of blue…

Arrow crabs are most active at night. They eat feather-duster worms (illus.) and similar invertebrates such as bristle worms.

Like certain types of shrimp, they also have a symbiotic relationship with anemones, whereby they make use of an anemone to benefit from the food it captures – and possibly for cover too. They are protected from anemone stings, whereas some of their predators are not.

This was the place where I was going to tell you about the arrow crab’s private life, but, well… “it’s complicated”. Briefly it is: male passes sperm-filled capsule to female; she uses it in some way whereby it fertilises her eggs; she then ‘broods’ the eggs in one of her ‘swimming legs’; the eggs hatch into larvae and swim off to eat plankton; each one then grows & moults, repeating the process until it has reached adult form. On balance, humans have arguably perfected a preferable method.

Arrow Crabs are apparently popular aquarium creatures, although they sound to me rather a disagreeable challenge. They can move quickly on those long legs, and it seems as if they inclined to be aggressive to other inhabitants of the tank. As far as I can make out, it’s best not to put 2 of them together: they certainly won’t be doing the sperm capsule thing described earlier…

Master of Disguise

Photo credits: Melinda Riger / G B Scuba (1, 3, 4, 5, 6); Adam Rees / Scuba Works (2, 8, 9); Nick Hopgood,Wiki (7); Chuck Elliot – video

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES

March 11, 2025 by Rolling Harbour

Keith Salvesen / Rolling Harbour

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES

As everyone knows, Hermit Crabs get their name from the fact that from an early age they borrow empty seashells to live in. As they grow they trade up to a bigger one, leaving their previous home for a smaller crab to move into. It’s a benign* chain of recycling that the original gastropod occupant would no doubt approve of, were it still alive… The crabs are able to adapt their flexible bodies to their chosen shell. Mostly they are to be found in weathered (‘heritage’) shells rather than newly-empty shells. [*except for fighting over shells]

HERMIT CRAB FACTS TO ENLIVEN YOUR CONVERSATION

The crabs are mainly terrestrial, and make their homes in empty gastropod shells
Their bodies are soft, making them vulnerable to predation and heat.
They are basically naked – the shells protect their bodies & conceal them from predators
In that way they differ from other crab species that have hard ‘calcified’ shells / carapaces
Ideally the shell should be the right size to retract into completely, with no bits on display

As they grow larger, they have to move into larger and larger shells to hide in
As the video below shows wonderfully, they may form queues and upsize in turns
Occasionally they make a housing mistake and chose a different home, eg a small tin

Keith Salvesen / Rolling Harbour

The crabs may congregate in large groups which scatter rapidly when they sense danger
The demand for suitable shells can be competitive and the cause of inter-crab battles
Sometimes two or more will gang up on a rival to prevent its move to a particular shell

HERMIT CRABS CAN EVEN CLIMB TREES – WITH THEIR SHELLS ON TOO

Tom Sheley

HERMIT CRABS EXCHANGING HOMES with DAVID ATTENBOROUGH

This is a short (c 4 mins) extract from BBC Earth, with David Attenborough explaining about the lives and habits of these little crabs with his usual authoritative care and precision . If you have the time I highly recommend taking a look.

Credits: All photos taken on Abaco by Keith Salvesen except for the tree-climber crab photographed by Tom Sheley; video from BBC Earth

SEAHORSES: PREHENSILE TALES FROM THE REEF

February 23, 2025 by Rolling Harbour

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s been quite a while since I wrote about these astonishing little creatures. Adam Rees of SCUBA WORKS is a diver who combines great underwater experience with wonderful photographic skills. Here is a showcase for some of Adam’s seahorse photography and the amazing detail he captures. If these images don’t make you want to get your head underwater and explore the reefs, I can’t think what will…

Seahorse (Adam Rees / Scuba Works)

RANGE MAP by NAT GEO

Seahorse (Adam Rees / Scuba Works)

shlifecycle-e1313548153493

Seahorse (Adam Rees / Scuba Works)

Seahorse by Alex Konahin

All fantastic photos: Adam Rees / Scuba Works; Range Map, Nat Geo; Lifecycle diagram, Seahorserun; Seahorse GIF, Alex Konahin

WORLD WHALE DAY . LEARNING FOR THE FUTURE

February 13, 2025 by Rolling Harbour

WWD FEBRUARY 16th 2025

Adult sperm whale with neonate calf [BMMRO Bahamas]

LEARNING FOR THE FUTURE

One way to celebrate the world’s whale populations is to learn about them from one of the many organisations that research and protect these fine animals. A good start is to become familiar with the types of whales, and see how they compare with each other. The simplest way to begin is to examine a Field Guide. This, hopefully, will catch your imagination and lead to further investigation.

What is a beaked whale – and can they really dive deeper than any other whale species? Do false and pygmy killer whales live up to the fearsome reputation of their orca cousins? Why are false and dwarf sperm whales so small in comparison to the enormous ‘real’ creature. Which whales are baleen and which are toothed? Why are humpback whales so different from other baleen whales? Finally the big question: is a killer whale a dolphin?

FIELD GUIDE TO THE MARINE MAMMALS OF THE BAHAMAS

To answer exactly these sorts of question and to inspire further study, BMMRO has produced a comprehensive Field Guide. Contained on four double-sided panels, there is a wealth of information about every species of cetacean found in Bahamian waters, including the dolphin species. And you can learn much more about BMMRO and its wide range of research and conservation projects HERE.

Meanwhile, below is the complete Guide in two versions, visual and downloadable. One click on the Guide’s images will enlarge them; 2 clicks will enlarge them further. The contents will remain legible. For those who want to dig deeper or who want to pass round the information, there is a download of the complete Guide.

The Guide has a significant educational value, and for example all students who attend the Summer Whale Camps are given one to study. You may use the guide images and / or the download as you wish.

DOWNLOADABLE GUIDE

BMMRO_Marine Mammal Guide – 96061 (1) copy 3 Download

*Neonate Sperm Whale Calf – Bahamas – BMMRO*

MAKE FRIENDS WITH ANEMONE (2): SPECTACULAR REEF LIFE

January 15, 2025 by Rolling Harbour

Corkscrew Anenome = Peterson Cleaner Shrimps ©Melinda Riger @G B Scuba copy

Corkscrew Anemone with Peterson Cleaner Shrimps

MAKE FRIENDS WITH ANEMONE

Going snorkelling? Planning a scuba day on the reef? You’ll see wonderful fish and amazing coral for sure. But sometimes the beauty of other life on the reef can be overlooked. Check out the anemone in the header image, with the camouflaged cleaner shrimps playing around it. You wouldn’t want to miss a sight like that. The many and varied forms and colours of anemone on the reefs of the Bahamas make up a vital component of a spectacular underwater world and its astonishing variety.

Giant Anenome ©Melinda Riger @ G B Scuba copy

Anemones are living animals of the invertebrate type. Basically living corals without skeletons. All have stinging cells of several varieties to sting or entangle their prey such as small fish, or other invertebrate species.

Anemone on Rope ©Melinda Riger @ G B Scuba

Most anemones host varieties of cleaner shrimps. They also provide a base for the snapping shrimps that can stun their own prey. Some of these can (painfully) penetrate human skin.

Anemone ©Melinda Riger @ Grand Bahama Scuba

Some crabs pull particular species of anemone off the reef and attach them to their carapace. This is thought to have a double purpose of providing both camouflage and protection.

Anemone (Giant) ©Melinda Riger @GBS copy

All great archive photos: Melinda Riger of Grand Bahama Scuba, with thanks; also Rick Guest for info

Anemone ©Melinda Riger @ GB Scuba

CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS

November 16, 2024 by Rolling Harbour

CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS

Pederson’s Shrimps Ancylomenes pedersoni (also known locally as Peterson’s shrimps), are one of several species of cleaner shrimp found in The Bahamas, and more generally in the Caribbean seas. The species was named in 1958 by a multifaceted medico-oceanologist-zoologist Fenner A. Chace. He seems to have specialised in shrimps, finding distinct and differing species and naming them (not unreasonably) after himself (chacei); or colleagues and people he knew / admired; and in one case his wife. Mr Pederson was among the lucky ones.

This tiny transparent creature with its vivid blue / purple markings and straggling pale antennae is unmistakeable, and helpfully cannot be confused with any other locally found shrimp species. Here’s an idea of its size, compared with a human finger and a blue parrotfish (on its flank).

WHERE DO THESE SHRIMPS LIVE?

Their preferred home is… and it’s certainly a left field choice among sea creatures… in amongst the stinging tentacles of certain sea anemones. Not only do they not get stung, but of course they are well-protected by the defensive pain that their hosts can inflict. They are usually found singly or in pairs, but sometimes a whole colony may inhabit the same anemone.

SO EXPLAIN HOW THEY DON’T GET STUNG

Ok. The shrimps gradually build up a kind of resistance by pressing their bodies and antennae against the tentacles of the host anemone for increasing lengths of time, until they become immune. It’s like one of those kids’ electric buzzer / rheostat machines. Or a TENS machine (for those who know about backache).

IS THERE A DOWNSIDE TO ALL THIS?

Yes indeed. If a shrimp moves away from its host for a few days, it has to start the process of immunisation all over again. So presumably they tend to stay home-lovin’.

Home sweet home for the Pederson shrimps Pederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

SOMETHING ABOUT THE CLEANING, PLEASE

These shrimps offer ‘cleaning services’ to passing fish. When on duty, as it were, they wave their antennae vigorously to attract attention. A fish being cleaned will remain stationary and passive while external parasites and dead skin are removed. Many fish will open their mouths and gill covers for internal cleaning, with the tacit agreement that the cleaner will not become a snack. Shrimps often work in conjunction with small cleaner fish such as some species of goby and wrasse – see the links below for more on this topic, with copious images…

CLEANING STATIONS

CLEANER FISH

Credits: all photos by Melinda Riger / Grand Bahama Scuba

IS THIS THE REAL LIFE? IS THIS JUST FANS AT SEA?

November 4, 2024 by Rolling Harbour

IS THIS THE REAL LIFE? IS THIS JUST FANS AT SEA?

A GALLERY OF GORGEOUS GORGONIANS

The waters of Abaco teem with myriads of fish that depend on the coral reefs for shelter and safety, for breeding, for growing up in, and for nourishment. Sea fans (or gorgonians, to use the technical name) are animals too. They may look like plants and stay rooted to the spot, but like anemones these ‘soft corals’ are creatures of the reef and essential indicators of its health.

The purple sea fan Gorgonia ventalina (classified by Linnaeus in 1785) is one of the most common species of sea fan, and a spectacular one at that. The main branches are linked by a lattice of smaller branches. Below the ‘skin’ is a skeleton made of calcite compounded with a form of collagen.

Sea fans are filter-feeders, and have polyps with eight tiny tentacles that catch plankton as it drifts past. They develop so that their orientation is across the prevailing current. This maximises the water passing by and consequently the supply of food as the fans gently wave in the flow.

Gorgonians have a chemical defence mechanism that protects against potential troublemakers. The main effect is to make themselves unpleasant to nibble or uproot.

One species impervious to this deterrent is the fascinating FLAMINGO TONGUE SNAIL. Other ‘safe’ species include the fireworm and BUTTERFLYFISHES.

One benefit of sea fans to mankind is that their defensive chemicals have been discovered to provide the basis for drug research and development, specifically in the field of anti-inflammatories. Another benefit, of course, is that they are very beautiful to look at. Thank you, Fans

Credits: these wonderful photos were taken by Melinda & Keith Rodgers / Dive Abaco, Marsh Harbour; and Melinda & Fred Riger / Grand Bahama Scuba. Huge thanks to them all for allowing me to freely use their skilful underwater photography in this blog for the best part of a decade.

A SPECIAL FAN FOR A HAPPY AND HOPEFUL TURN OF THE YEAR

WORLD DOLPHIN DAY 2024

September 12, 2024 by Rolling Harbour

September 12th is the day chosen by Sea Shepherd to raise awareness and promote the conservation of dolphins. It was established on the one-year anniversary of the killing of 1,428 Atlantic white-sided dolphins in the Faroe Islands, which was the largest single slaughter of cetaceans in history.

As many will know, the marine mammals of the Bahamas – whales, dolphins and manatees – are researched and protected by the Bahamas Marine Mammal Research Organisation. This was established more than 20 years ago by Diane Claridge and Charlotte Dunn.

You can find out more about the nature and scope of the work carried out by BMMRO HERE Please consider making a donation to support the work of BMMRO, or (for those elsewhere in the world), to the marine mammal organisation in your area. Dolphins increasingly need protection from mankind and human activities. A donation would greatly help provide it.

All Photos: BMMRO

MANATEES: ENJOY THEIR INTERNATIONAL DAY

September 8, 2024 by Rolling Harbour

MANATEES : BAHAMAS? WE GOTTEM!

Manatees are apex ‘gorgeous marine mammals’. Gentle, inquisitive, brave, long-distance-but-rather-slow-swimming, grass-grazing miracle ur-elephant descendants. They never made it out of the sea in the Miocene epoch.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

Incongruous in a world of fast sharks, snappy ‘cudas, large whales and leaping dolphins, they contentedly mooch around the seagrass beds. No one in the world has ever objected to or dissed a manatee. They bring only delight to the sea-world, and offer only charm to mankind. They thoroughly deserve a special day.

Manatee Awareness Graphic (Peppermint Narwhal)

I’ve written before about the manatees that inhabit the turquoise inner waters of the Bahamas. They are carefully recorded with individual identifying features – usually nicks in the paddle, or scarring. They are named and, where possible, fitted with a tracker. Their friendships and amorous hook-ups are noted. Despite a 16-month birth cycle, manatee calves are born.

IS THERE A DOWNSIDE FOR THESE APPARENTLY BLISSFUL AND PEACEFUL CREATURES?

Yes indeed. It’s mankind, I’m afraid. Among the threats to the survival of these unusual, endearing, and legally protected creatures are, in no particular order:

Pollution of inshore waters and canals
Degradation of the (formerly limitless) sea-grass beds where they feed
Reduction or tainting of the fresh water sources that they need to survive
Understandable over-enthusiasm by admirers – especially in harbours – in dousing them with water from hoses and feeding them lettuce…
…and similar behaviours that may lead to a trusting dependance on humans
Unthinking or speed-selfish boat behaviour in or near harbours resulting in collisions
Simply not caring at all and carving them up, leaving prop-scars, often deep. Few manatees escape at least a few of these. Some do not survive.
Probably I don’t need to mention man-caused Global Warming, but I just have.

Let’s celebrate the special day for manatees. Let’s hope that they can survive and prosper in these increasingly difficult and dangerous times for almost all species. Look at any of these photos… can we agree that these wonderful animals deserve care and protection.

All photos: Charlotte Dunn / BMMRO and research contributors; final image ‘Save the Manatee’

PLEASE SUPPORT BMMRO RESEARCH OF MARINE MAMMALS

YELLOWTAIL PARROTFISH: BAHAMAS REEF FISH (54)

August 18, 2024 by Rolling Harbour

YELLOWTAIL (REDFIN) PARROTFISH: BAHAMAS REEF FISH (54)

The yellowtail parrotfish (sometimes known as a redfin) is one of around half-a-dozen kinds of parrotfish found among the coral reefs of the Bahamas, and sometimes in seagrass areas. There are many other related species worldwide (about 80). Parrotfish are among the most important fishes on the reef because they play a major role in BIOEROSION , a vital process for the health of the reef.

A. FEEDING & BEACH BUILDING

Their dental arrangements – a mouthful of meshing teeth – form the characteristic ‘beak’
Primarily herbivores but also snack on small creatures, organisms, or even molluscs
As they feed on their favourite algae, their teeth grind up the coral which they ingest
They digest the coral & excrete it as sand, becoming a component of your favourite beach
The teeth grow continuously, replacing ones worn away by grinding coral as they graze
They are a vital species in preventing algae from choking coral: essential reef cleaners

B. PARROTFISH: PERSONAL INFORMATION

Some secrete a protective mucous cocoon to sleep in or as concealment from predators
Mucous also helps to heal damage, repel parasites, & protect them from UV light
As they develop from the juvenile stage, most species change colour significantly
In some species, juveniles change colour temporarily for protective purposes
These are “sequential hermaphrodites”, turning from female to male (‘protogyny’)
Single males tend to have several lady friends, and aggressively defend their love rights
Parrotfish are PELAGIC SPAWNERS. Females release many tiny buoyant eggs into the water
The eggs float freely then eventually sink to the coral until they hatch
Unlike almost all other fishes, they use their pectoral fins to propel themselves
Feeding behaviour / dietary requirements make them (thankfully) unsuitable for aquariums (or aquaria, if you prefer)

WHAT WAS THAT ABOUT CHANGING SEX?

Parrotfish may undergo sex reversal in which developing female fish become males
Parrotfish born male remain male throughout their lives (“primary males”)
Female-born fish may change sex & colour to become male (“secondary males”)
Secondary males are fertile and generally mate with a single female
Females that stay female live in harems protected by a dominant “supermale” BUT…
…if the supermale dies, the largest female in the group changes sex to become male…
…AND amazingly adopts the coloration of the supermale (best ‘astounding fact’ of all)

ARE PARROTFISH EDIBLE? JUST ASKING…

Parrotfish skin is very tough but their flesh is soft and degenerates quickly
Some species (eg blue parrotfish) carry ciguatera toxins – to be avoided
They are not considered a fishing target in Bahamas, nor a food-fish
Parrotfish are eaten elsewhere in the world however, for example Jamaica (cooked)
In Hawaii they are eaten raw – at one time they were reserved for royalty

VIDEO LINK: PARROTFISH POOP

Credits: Melinda Rogers / Dive Abaco for her great illustrative images. All photographs were taken on the reefs of Abaco; Florida Museum to cross-check facts; VIDEO – Angari Foundation

CREOLE WRASSE: SHADES OF DEEP PURPLE

July 23, 2024 by Rolling Harbour

CREOLE WRASSE: SHADES OF DEEP PURPLE

The creole wrasse Clepticus parrae is a small wrasse species, with adult males reaching about 12 inches long. During its life, the fish will change colour significantly. A juvenile is almost completely violet-purple. As it matures, it becomes paler and develops patches of yellow on the rear part of its body.

Creole wrasse are found throughout the tropical and subtropical waters of the western Atlantic, from Florida south to Brazil. The habitat includes Bermuda, the Caribbean Sea, and the Gulf of Mexico. Their conservation status is LC Least Concern.

These are social fish that live in groups around coral reefs. They are usually found in shallow water, but – perhaps surprisingly for such small creatures – they have also been found as deep as 100m.

The groups of wrasse feed on plankton, small jellyfish, pelagic TUNICATES, and invertebrate larvae. They are active in groups by day, but at night they separate and each fish finds its own safe crevice in the reef to sleep.

ANYTHING ELSE WE NEED TO KNOW?

Yes indeed. Their intriguing breeding regime – how unlike our own dear species. The creole wrasse is a protogynous hermaphrodite. The largest fish in a group is a dominant breeding male, while smaller fish remain female. If the dominant male dies, the largest female changes sex. Mature males congregate at leks to breed, at which they display and are approached by females before mating with them. These leks are reminiscent of certain clubs and bars in the less reputable parts of some towns and cities. Or so I am told.

It’s been a while since I included a Rolling Harbour musical diversion. However, the colour of this small fish nudged my memory back to 1968 and DP’s debut album (line-up Mk 1 of several hundred, or so it seems now). Hence the post title. Anyone who remembers this ‘wasn’t there’. Anyone who doesn’t remember it obviously wasn’t there either…

FUN FACT: an early appraisal of the Purp’s music includes the description “a slow and pompous din, somewhere between bad Tchaikovsky and a B-52 taking off on a bombing run”

I don’t think this guy thinks much of that. And quite right too