CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX

April 27, 2024 by Rolling Harbour

CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX

The Caribbean reef squid Sepioteuthis sepioidea is a small squid species of (mainly) the Caribbean Sea and the Floridian coast, and the most common in its range. These squid tend to form small shoals in and around reefs. From now on, and through the summer, would be a good time to investigate.

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

Squid are voracious eaters, dragging their prey to their mouths with some or all of their 10 limbs and using their beak to cut it up. The target species are small fish, molluscs and crustaceans. The squid have a ‘raspy tongue’ known as a radula which further breaks up the food for easy consumption.

REEF SQUID SUPERPOWERS (SUPERCOOL)

Squid are capable of brief flight out of the water (a fairly recent discovery)
They can also hide from / confuse predators by ejecting a cloud of black ink
Squid can change colour, texture and shape, and can even match their surroundings
This enviable power is used defensively as camouflage or to appear larger if threatened
It is also used in courtship rituals (something that humans might find disconcerting)
Colour patterns are also used for routine squid-to-squid communication AND GET THIS:
A squid can send a message to another on one side, & a different message to a squid on its other side

SQUID SEX (1) “ROMANCING THE SQUID”

A male will gently stroke a female with his tentacles
The female will (most likely) flash an ‘alarm’ pattern. She’s playing hard to get.
The male soothes her (don’t try this at home, guys) by blowing and jetting water at her
If this doesn’t go well, he’ll move off, then repeat the routine until she sees his good points
However this on / off courtship can last for hours until at last he succeeds and then…
… he attaches a sticky packet of sperm onto the female’s body (romance is not dead on the reef)
She then reaches for it and moves it to her seminal receptacle
Meanwhile he stays close, emitting a pulsing pattern, as well he might after all that palaver
She then finds a safe place to lay her eggs. Job done. **

SQUID SEX (2) IT ALL ENDS BADLY. VERY BADLY.

As soon the female squid has laid her eggs, she usually dies soon after
Male squid live a bit longer and – erm – may have other packets to stick on other lady squid
But then in the end he dies too
It’s all horribly reminiscent of Romeo and Juliet. The lovers tragically die in the end (but there’s no romantic balcony scene first)

THE CORRECT PLURAL OF SQUID

I had an unwise look online, always a hotbed of conflicting opinions. Inserting an algorithm into the interstices of the internet proves conclusively that the plural of squid is… squid. One squid, ten squid, a group of squid, a plate of squid. Unless, that is, you are talking about more than one of the many squid species, when you could possibly say ‘I collect both reef and giant squids’. “Squidses” sounds fun but is sadly not permitted.

RELATED POST (from the past): THE PLURAL OF OCTOPUS

** For an excellent article about squid including the intricate details of courtship and reproduction (and an image of a squid penis) check out SQUID WIKI

Credits: Fabulous underwater pics – Melinda Riger of Grand Bahama Scuba; research sources include MarineBio; Animal Diversity Web (Michigan Uni); and Wiki, which comes into its own in some fields of natural history where experts write the entry)

WTF? (WHAT’S THAT FISH?) . YELLOWHEAD JAWFISH

March 31, 2024 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) . YELLOWHEAD JAWFISH

The WTF series is designed to bring some of the more outlandish reef denizens under close scrutiny. Jawfishes (Opistognathidae) come into this category, not least because of their interesting ways with their eggs. Also, they tend to stick upright out of the substrate, which is not especially fishy behaviour.

More than 50 species of jawfish are found around the world. In the Bahamas, you are most likely to encounter the Yellowhead (or Yellow-headed) variety. And if you think they look slightly… primitive, that’s because they are. In fact, their forebears (forefishes?) originated in prehistoric times, specifically the Miocene era (a lot of million years ago, I didn’t count exactly).

These rather extraordinary little fish superficially resemble certain types of BLENNY. Their modus operandi is to burrow down into sandy, gravelly or other loose substrate. They do so by cramming their mouths with sand and spitting it out to one side. By this means they form a tunnel of sorts in which they can live, and from which they can emerge, or half-emerge and take a look around them. As they do so, they hoover up passing food, mostly plankton and suchlike.

If something looks threatening while they are feeding or having a look around, they can simply duck down into their burrow for safety. They guard their patch against rivals, and behave ‘territorially’ in the jawfish community. One method is to ingest and then eject sand or gravel at a would-be intruder.

YES, BUT WHERE IS THE REAL ‘WTF?’ FACTOR HERE?

Good question. With a good and original answer. These little creatures are so-called ‘MOUTHBROODERS‘, meaning that they carry their eggs in their mouths. Depending on the species, females, males or even both parents (don’t try this at home) will do this at or after fertilisation. In effect the eggs are safely incubated until they hatch as fry. Then they are on their own.

ARE THERE ANY DRAWBACKS TO THIS UNUSUAL GESTATION METHOD?

Apart from accidentally swallowing the occasional potential junior, the eggs need aeration from time to time. This is achieved by expelling the eggs from the mouth, and quickly sucking them back in again. Try this very short video to see this rather improbable behaviour in action. It’s only 8 seconds – blink and you’ll miss the action. The eggs hatch into fry in 8 – 10 days, after which both parents can relax. Until the next time.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

Photo Credits: all images from Melinda Riger / Grand Bahama Scuba except (4) Virginia Cooper / GBS; (5) Michael Wolf / Wikimedia; video, Alan Keller. Research: magpie picking, not excluding yet not limited to Wiki…

WTF? (WHAT’S THAT FISH?): SCORPIONFISH

February 12, 2024 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 15: SCORPIONFISH

The WTF? series is aimed at shedding light on fishes that are unusual. Or very unusual. Or puzzling, dangerous and maybe less than elegant in appearance. The scorpionfish is one such. It belongs to a large family, the Scorpaenidae, and many types are found throughout the world, especially in the Pacific and Indian oceans. LIONFISH, the newcomers to the western Atlantic, are a species of scorpionfish.

Just another rock on the seabed… Caribbean Scorpionfish, Bahamas (Melinda Riger / G B Scuba)

WHY ‘SCORPIONFISH’? THEY LOOK SCARY. ARE THEY DANGEROUS?

One feature common to many scorpionfish species is that they are highly venomous. As the name suggests, a sting is involved. Or several stings. These come from the creature’s sharp spines, which are coated with mucus, and are to be avoided. If you want to pet one, the dorsal, anal and pelvic fins are the ones to steer clear of – these all have venom glands at the base. The spines act like injection needles. Scorpionfish aren’t naturally aggressive (except to prey), but they know how to defend themselves if need be. If you get ‘got’, you are in for “extreme pain and burning sensation”.

DO THEY HAVE ANY OTHER TRICKS TO WATCH OUT FOR?

As many have written, scorpionfish are ‘Masters of Camouflage’. They are able to disguise themselves very effectively. Their appearance is a remarkably adapted to their surroundings, as if covered in a raggle-taggle of colourful algae. They can change colour to aid concealment. They can flick sand over themselves as they settle on the seabed. These ploys enable them to lie motionless on a coral reef or on the seabed, ready to ambush their prey. This consists mainly of small fishes and crustaceans, but really anything edible that will fit in their mouths is fair game.

Concealed against coral

HOW DO THEY FEED?

The large mouth of scorpionfishes has a particular function. They don’t have teeth because they have no need. A scorpionfish can open its mouth and its gills simultaneously, thereby creating an instant vacuum that will suck in its prey in a flash. I have seen this described as “a nearly imperceptible split-second movement (15 milliseconds)”…

THESE SCARY MONSTERS MUST BE HUGE, RIGHT? I’M KEEPING OUT OF THE WATER

Not so fast. When all is said and done – and in my view, most disappointingly – adult Caribbean Scorpionfish grow in the range of… erm… 7 – 14 inches. So now you are reassured, here’s a great short video from Ocean Frontiers Dive Shop, who kindly shared it on YT. I’ve used a couple of illustrative stills from it too.

ANYTHING ELSE WE NEED TO KNOW?

I can do no better than to turn to Card 81 to the excellent ‘Monsters of the Deep‘ series of trading cards (the link is to my MotD page). I do realise that this is a rather unscientific approach. On the other hand these guys pack memorable information into a very short space, and do it well. Note that you can get a reflex sting from a scorpionfish for up to a week after it has died. Eat dust, earthbound scorpions.

Credits: Melinda Riger / Grand Bahama Scuba (1, 2, 3, 4,); Ocean Frontiers Dive Shop (video from YT, 2 stills); Wierd (sic) Creatures / Monsters of the Deep (O/S)

SOUTHERN STINGRAYS: BAHAMAS REEF FISH

October 12, 2023 by Rolling Harbour

SOUTHERN STINGRAYS: BAHAMAS REEF FISH (41)

Anyone who has scuba-dived or snorkelled around the bright coral reefs of the Bahamas, or hunted bonefish out on the Abaco Marls will have come across Southern Stingrays Dasyatis americana. And there are certain places (eg Manjack Cay) where you can actually feed them – and not come to any harm…

FEED THEM? AREN’T THESE GUYS LETHALLY DANGEROUS CREATURES?

The name that always comes to mind in connection with stingrays is poor Steve Irwin, the charismatic Australian wildlife expert who was tragically ‘stung’ over his heart as he swam close over a ray while filming underwater. But this was, it would appear, a dreadful combination of circumstances with a terrible outcome.

The ray’s stinger is in fact an erectile venomous barbed spine near the base of the tail and not on the end of it (as one might expect). But these creatures are not out to harm you – though of course when you are in their environment you should accord them the respect that they merit.

If you are walking / wading in the water, avoid the risk of accidentally treading on a ray. Best to shuffle your feet forward in the sand; if there’s a half-concealed ray feeding or resting on the bottom nearby, it will swim away peacefully. I took the photo below while bonefishing on the Marls; the ray directly ahead slowly makes off as the skiff drifts closer. The next one is of a ray with its young – completely aware of us as we glide past to one side, but not especially bothered.

If you are swimming, snorkelling or diving, don’t get too close – especially by swimming directly over a ray (apparently Steve Irwin’s mistake, so that he was struck right in the chest by the stinger when the ray reacted).

Enough of the potential dangers. The southern stingray is a magnificent creature, as Melinda’s wonderful photographs show. She spends half her life underwater and I’m not aware that she has had a problem with a ray.

Like many larger sea creatures, stingrays need help with their personal care – the removal of parasites, dead skin and so forth. And so they make use of the services offered by small fish like gobies, wrasses and shrimps at a CLEANING STATION. Here are 2 photos of rays doing just that. You can see the tiny fish by the reef, going about their work. There’s a mutual benefit in this symbiotic relationship, in which it is understood that the cleaners are unharmed. Indeed, they will often enter the mouths and gills of a fish to clean… including the teeth. So there’s dental hygiene on offer too…

RELATED POSTS

YELLOW STINGRAY

GRACE WITH ATTITUDE

TAKEN TO THE CLEANERS

Photo Credits: Melinda Riger / Grand Bahama Scuba, except for the feeding photo (cheers, Samantha Regan), the ‘specimen’ from Tomas Willems (Wiki) and my two noted above

WTF? (WHAT’S THAT FISH?): ARROW CRABS

July 14, 2023 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

ROCK BEAUTY: BAHAMAS REEF FISH

April 7, 2023 by Rolling Harbour

ROCK BEAUTY . Holacanthus tricolor . BAHAMAS REEF FISH

These creatures are a small species of angelfish. Seen swimming around the reefs they are unmistakeable, not least because of their bright yellow hi-viz jackets, remarkable blue eyeliner and blue-black lipstick.

Rock Beauties look like prime candidates for anyone’s aquarium, but they have picky dietary requirements and a tendency for aggression that make them unsuitable (fortunately for them).

They are highly specialised feeders, needing marine sponges in their daily diet. They are also prone to chase tank-mates and nip them. On balance, they look more fetching nosing about the coral anyway.

WHAT DO JUVENILES LOOK LIKE?

Juvenile rock beauties are cute mini-versions of the adults, only even more yellow and with yellow lips.

In development stages, they may have a vivid blue and black circle in front of the tail fin…

… or a large dark patch on their sides

NOT A TRUE ‘ROCK BEAUTY’ (no offence, Lita)

A TRUE ROCK BEAUTY

Credits: Melinda Riger, Grand Bahama Scuba; WP

BLUEHEAD WRASSE: PRIVATE LIFE LAID BARE

January 23, 2023 by Rolling Harbour

BLUEHEAD WRASSE: PRIVATE LIFE LAID BARE

The bluehead wrasse (or blue-headed wrasse) Thalassoma bifasciatum is a denizen of the coral reefs in the tropical waters of the western Atlantic Ocean. This bright little 4-inch fish is… a wrasse with a blue head. No more and no less. Unless it’s a juvenile. Then it is mainly bright yellow. It’s similar to BLUE TANG (aka ‘the Disney Dory’), which starts life bright yellow and grows up to be blue.

The species may be found singly, in pairs or small groups, or in schools. They have an important role to play in the life of the reef. They are CLEANER FISH, vital to the health and wellbeing of the larger species they attend to, and thus of the reef itself. This is ‘cleaning symbiosis’, a relationship of mutual benefit. The big fish get cleaned; the little fish have a useful function and – importantly for them – therefore don’t get eaten.

Having said that, blueheads are of course fair game as a snack for species that aren’t in the market for their cleaning services. Rather unfairly, some species that are quite content to let cleaner gobies pick around their gills and mouths are not so considerate of the wrasse (some types of grouper and moray eel, for example).

TELL US EXACTLY SEVEN BLUEHEAD WRASSE FACTS

Juveniles can alter the intensity of their colour, stripes & bars
The bluehead wrasse is a ‘protogynous sequential hermaphrodite’
All are born female**. Some change sex to male during maturation (see below)
Food includes zooplankton, small molluscs and small crustaceans…
…and parasites / other juicy bits (fungal growths, anyone?) from bigger fish
Main threats to the species are coral reef degradation / destruction and pollution
The bright colours invite aquarium use, but the trade in this species is not critical.

** Some sources suggest some are born male and remain male.

A juvenile bluehead – mostly yellow, with a pale underside

THE REMARKABLE SEX LIFE OF THE BLUEHEAD WRASSE

This is an unavoidable topic, I’m afraid. The bluehead’s sex life is the most interesting thing about them, and this is no time to be prudish. It has been the subject of extensive scientific research. As with many human relationships, “it’s complicated” but in a conch shell it boils down to this:

To recap, BWs are born female and as they mature, some become male.
Males reach an ‘initial phase’ when they can breed in groups with females
Some males grow larger & reach full colouration. This is the ‘terminal phase’
These large males aggressively chase away smaller ones & seek females to pair with
Their state of readiness is signalled by colour changes BUT the females know…
…that the smaller males have a sperm count higher than dominant males.

As the excellent organisation OCEANA puts it: Bluehead Wrasses may reproduce in four different ways throughout their lifetime: 1) as a female in a group spawning event; 2) as a female in a pair spawning event within the territory of a large male; 3) as a small male in a group spawning event; and 4) as a dominant, terminal male in a pair spawning event within its own territory.

A cropped still from a video I took at Fowl Cay marine reserve. I’ve looked at dozens of images online and not found one that was all blue with a yellow end to its tail fin. Perhaps it is just an all-blue alpha male.

Credits & Sources: Melinda Riger; Adam Rees; James St John; Oregon State edu / Pinterest; Wiki images; self; Oceana; IUCN; magpie pickings

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

December 19, 2022 by Rolling Harbour

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.

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

WHAT DOES ‘TUNICATE’ MEAN?

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

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.

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.

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

CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX

April 18, 2022 by Rolling Harbour

CARIBBEAN REEF SQUID: SUPERPOWERS & SQUID SEX

The Caribbean reef squid Sepioteuthis sepioidea is a small squid species of (mainly) the Caribbean Sea and the Floridian coast, and the most common in its range. These squid tend to form small shoals in and around reefs. From now on and through the summer would be a good time to investigate.

Caribbean Reef Squid, Bahamas (Melinda Riger / G B Scuba)

REEF SQUID SUPERPOWERS (SUPERCOOL)

Squid are capable of brief flight out of the water (a fairly recent discovery)
They can also hide from / confuse predators by ejecting a cloud of black ink
Squid can change colour, texture and shape, and can even match their surroundings
This enviable power is used defensively as camouflage or to appear larger if threatened
It is also used in courtship rituals (something that humans might find disconcerting)
Colour patterns are also used for routine squid-to-squid communication AND GET THIS:
A squid can send a message to another on one side & a different one to a squid on its other side

SQUID SEX (1) “ROMANCING THE SQUID”

A male will gently stroke a female with his tentacles
The female will (most likely) flash an ‘alarm’ pattern. She’s playing hard to get.
The male soothes her (don’t try this at home, guys) by blowing and jetting water at her
If this doesn’t go well, he’ll move off, then repeat the routine until she sees his good points
However this on / off courtship can last for hours until at last he succeeds and then…
… he attaches a sticky packet of sperm onto the female’s body (romance is not dead on the reef)
She then reaches for it and moves it to her seminal receptacle
Meanwhile he stays close, emitting a pulsing pattern, as well he might after all that palaver
She then finds a safe place to lay her eggs. Job done. **

SQUID SEX (2) IT ALL ENDS BADLY. VERY BADLY.

As soon the female squid has laid her eggs, she usually dies soon after
Male squid live a bit longer and… may have other packets to stick on other lady squid
But then in the end he dies too
It’s all horribly reminiscent of Romeo and Juliet. The lovers die in the end (but there’s no romantic balcony scene first)

THE CORRECT PLURAL OF SQUID

RELATED POST (from the past): THE PLURAL OF OCTOPUS

** For an excellent article about squid including the intricate details of courtship and reproduction (and an image of a squid penis) check out SQUID WIKI

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

April 10, 2022 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, and in some instances to have their gills and even their teeth cleaned. The deal is that, in return, the large fish do not eat the cleaners. Even snack-sized ones rootling around inside their mouths.

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 (my italics). 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 is unrelated to the fond name for a grandmother; rather, it simple 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. In a nutshell, the link between the town and places of education is that the Sisters of Loreto, founded in the c17 and named for a shrine in the Italian village, are dedicated to education in their Ministry.

How that ties in with a tiny Caribbean reef fish, I have yet to find out. I probably never will… Here’s a short video to alleviate the disappointment.

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

SEAHORSES: PREHENSILE TALES FROM THE REEF

January 29, 2021 by Rolling Harbour

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s a while since I showcased 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

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

January 15, 2021 by Rolling Harbour

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

HOW DO THEY FEED?

Diagram of adult solitary tunicate

WHAT DOES ‘TUNICATE’ MEAN?

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

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

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

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

SHARK ATTACKS – ABACO, BAHAMAS, & BEYOND

August 3, 2020 by Rolling Harbour

SHARK ATTACKS – ABACO, BAHAMAS & BEYOND

DATABASE UPDATE 2023

ANNOUNCEMENT

DECEMBER 18 2023

Two days ago, a woman was tragically killed by a shark off Nassau. She and her husband were paddleboarding nearly a mile offshore. Few details have been reported at present, as is only right in the circumstances. In November there had been a presumed fatality off West End, Grand Bahama when a woman diver was attacked and has not been found. Such incidents are exceptionally rare for the region, with Bahamas having a consistent history of low attack figures.

This page has had a great many visits over the past 48 hours, for obvious reasons. At this time further comment would be quite inappropriate. We extend deep and respectful sympathy to the families and friends of those involved. Such terrible events should be given due privacy for those who are grieving.

This notice has also been posted on the other differently arranged Shark Attack page HERE

=========================================================================

DATABASE UPDATE 2022

Screenshot 2023-12-05 at 17.02.52

SUMMARY

Global total of unprovoked shark bites significantly lower than average

Country	Total	Fatal
USA	41	1
Australia	9	0
Egypt	2	2
South Africa	2	2
Brazil	1	0
New Zealand	1	0
Thailand	1	0
Worldwide	57	5

The 2022 worldwide total of 57 confirmed unprovoked cases is lower than the most recent five-year (2017-2021) average of 70 incidents annually. There were nine shark-related fatalities this year, five of which are assigned as unprovoked. This number is in line with the 5 year annual global average of six unprovoked fatalities per year.

Annual fluctuations in shark-human interactions are common. Despite 2021’s spike in fatalities, 2022 was a return to typical long-term trends which show a decreasing number of annual fatalities. Year-to-year variability in oceanographic, socioeconomic and meteorological conditions significantly influences the local abundance of sharks and humans in the water.

BAHAMAS STATS

Confirmed Unprovoked Shark Attacks (1749-Present)

Risk of being bitten by a shark remains extremely low

Short-term trends show both fatal and non-fatal bites to be decreasing. The total number of unprovoked shark bites worldwide is extremely low, given the number of people participating in aquatic recreation each year. Fatality rates have been declining for decades, reflecting advances in beach safety, medical treatment and public awareness.

DATABASE UPDATE 2021

INTERNATIONAL SHARK ATTACK FILE

Over the last couple of weeks or so I have been getting a lot of hits for Shark Attack information. There have been 2 or 3 recent incidents including a tragic (and very rare) death in Maine, which may well account for this. The Shark Attack details I have accumulated and posted over the years are buried in an historical sub-sub-page, so to make things easier I have re-checked and updated the latest data resources and their links, and put them in a mainstream post. This is it.

DATABASE UPDATE 2020

INTERNATIONAL SHARK ATTACK FILE

PRIMARY RESOURCE

This resource is the portal to a mass of current, recent, and historical data, presented with authority and clarity. It provides undoubtedly the most comprehensive and accessible global shark-incident data of all.

Last year I included informative screen-shots taken from this site. For now I am confining the information to the most useful direct links. More work for the reader, perhaps, but also a better chance to explore and understand the hows, whens and wherefores of shark-related incidents – and how best to avoid the situation in the first place.

SITE LINK

https://www.floridamuseum.ufl.edu/shark-attacks/

BAHAMAS-SPECIFIC

https://www.floridamuseum.ufl.edu/shark-attacks/maps/na/bahamas-antilles/

“The 2019 worldwide total of 64 confirmed unprovoked cases were lower than the most recent five-year (2014-2018) average of 82 incidents annually. There were five fatal attacks this year, two of which were confirmed to be unprovoked. This number is in line with the annual global average of four fatalities per year“

MENU SELECTION

Maps & Data Contributing Factors Shark Attack Trends

What are the Odds? Reducing Your Risk

For anyone thinking of entering waters where sharks live – eg scuba divers, spear-fishers, swimmers, boaters – with relatively little experience or knowledge, these links will be incredibly useful. Local knowledge is well worth having as well. A young friend of ours, an intern on Abaco, was warned against spearfishing at a particular location: “Fish there, you’ll get ate”. He did. He very nearly was.

“Humans are not on the menu of sharks. Sharks bite humans out of curiosity or to defend themselves”

The SRI produces a downloadable Global Shark Attack File that provides:

A downloadable incident log by country
A downloadable incident log chronologically
A world map of encounters categorized by provoked vs. unprovoked, incidents involving boats, air & sea disasters and questionable incidents
To read any basic case report, open the Chronological file, click on the case number (column A) and the report will open as a pdf file

SHARK SPECIES (CONCISE OVERVIEW FOR EACH SHARK)

http://www.sharkattackfile.net/species.htm

BAHAMAS-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas

ABACO-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas/abaco_islands

Credits: All great shark photos – Melinda Riger / Grand Bahama Scuba; ‘Infest’ sticker design, Tracie Sugo

A FINAL THOUGHT

EEL-SPOTTING: FORAYS WITH MORAYS (7)

December 9, 2019 by Rolling Harbour

EEL-SPOTTING: FORAYS WITH MORAYS (7)

MORAY EELS are plentiful around the reefs of the Bahamas. Some species, anyway. The ones you are most likely to encounter are green morays, and the spotted morays shown here. Less common are chain and golden-tail morays and, rarer still I suspect (because I have only one image in the archive…) is the ‘purple-mouth’.

Despite their moderately intimidating appearance – an adult may grow to 1.5 meters or more, with sharp teeth at the front end – these eels are not especially aggressive unless provoked. Best to assume that all humans will behave respectfully around them and remember that people are the intruders in the eels’ domain.

Morays tend to be loners of the reefs, but they do gather in groups from time to time. And as shown below, they will also hunt with other species, for example this tiger grouper.

Sharp-eyed, sharp-toothed

Looks friendly enough…

A long and surprisingly large body, generally concealed in the crevices of the reef

Credits: Melinda Riger / Grand Bahama Scuba

Lurkin’ Good

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE

August 6, 2019 by Rolling Harbour

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE

There’s never a day without a ‘Day’, nor a week without a ‘Week’. Almost all creatures under the sun are celebrated in some regular calendar-based time-frame. With the exception of No-see-ums: I’ve checked – there is no national or international Ceratopogonidae Day in any online calendar.

By a mere 2 days, I have missed Shark Week, a happening tied in with the Discovery Channel, and heralded by an amusing trailer that features no actual sharks… So, belatedly, here are some cool shark photos to enjoy, in case you didn’t get enough of them last week, or (like me) had other fish to fry.

“I’m so glad we agreed to watch each other’s backs…”

Meet Nurse Betty, as she is known to divers

MANGROVES: THE SHARK NURSERY

As all children are taught and some adults know, the mangroves that grow in the shallow waters around the islands of the Bahamas are of enormous ecological significance. This isn’t the place to expand on that now, but it is worth mentioning that the mangrove swamps are the nurseries of young sharks (‘pups’) until, as juveniles, they are old enough to leave the safely of their home for deeper waters. Check out the short video below.

Spot the REMORA hitching a ride on this shark’s back

Nurse shark – note the twin barbels (cf recent Goatfish article)

HAMMERHEADS FROM BIMINI

These wonderful photos were all taken in Bahamian waters. Melinda Riger of Grand Bahama Scuba is, as ever, the star snap-getter of sharks (and indeed all other marine creatures). Special thanks are also due to Grant Johnson / 60poundbullet and Neal Watson / Bimini Scuba Center for occasional use permission of photos – especially of hammerheads – that are, well, eye-popping. Video from ‘ZeroEye’

MEET ARNOLD: BE A BAHAMAS BLACK GROUPER GROUPIE

June 11, 2019 by Rolling Harbour

MEET ARNOLD: BE A BAHAMAS BLACK GROUPER GROUPIE

The Black Grouper, like all its cousins, has the twin disadvantages of being fished for sport and fished for food. As demand for grouper on the menu rises, so does its vulnerability. The species is described as a ‘slow breeder’, so a depleting population has less chance of sustaining numbers. The consequence is an exponentially diminishing stock of the species. The equation is simple: fewer fish means less and less stock replenishment.

Formerly plentiful, these groupers (like other grouper species) have moved from an IUCN listing of ‘Least Concern’ to ‘Near-Threatened’. Whatever effect climate change may be having on the oceans, stock depletion of this noble species also has more direct human causes.

An adult black grouper’s diet consists of small fish and squid. Juveniles feed primarily on crustaceans. However, certain tiny reef fish – blennies and gobies for example – are important to the species as ‘cleaners’. You can read about their significance by clicking CLEANING STATIONS.

The service performed by tiny fish on large ones (not only groupers) is an example of a symbiotic relationship known as ‘mutualism’**, in which both parties benefit (the little fishes get gacky bits of grouper to eat). The cleaners are able to do their work inside the gills and even the mouth of the host without being at risk.

The NASSAU GROUPER has a defined and enforced closed season to help maintain numbers. It will be interesting to see if the same protection is eventually extended to the black grouper and indeed to other grouper species.

** The other two types of symbiotic relationship are commensalism, in which only one species benefits while the other is neither helped nor harmed; and parasitism, where one creature (the parasite) gains, while the other (the host) suffers.

RELATED POSTS

Credits: all photos Melinda Riger of Grand Bahama Scuba

BAHAMAS TURTLES: BE AWARE BUT DON’T BEWARE

May 23, 2019 by Rolling Harbour

Green Turtle Eye (Melinda Riger / Grand Bahama Scuba)

GREEN TURTLE WATCHING

BAHAMAS TURTLES: BE AWARE BUT DON’T BEWARE

MAY 23 is another one of those ‘species awareness’ days. Somewhere in the world, it seems that every day of the year has a creature to be aware of. As the Sixth Extinction looms (the one we’ve promoted in basically two generations), a state of heightened awareness is where we should all be at.

TURTLES BY ADAM REES / SCUBA WORKS

That’s not an end in itself of course – it’s merely the first step to doing something about the species in question… and beyond that, every species. We’ve screwed up their world for them. Awareness is just a wake-up call to action. Support a cause. Join an organisation or group. Support campaigns. Sign up. Write stuff. Do stuff. Don’t do other stuff. Even wearing a “Save the Great-crested Newt” T-shirt would be better than nothing.

TURTLES BY MELINDA RIGER / GRAND BAHAMA SCUBA

Back to the turtles. I have featured a few great sea turtle photos (none of them mine) to concentrate the mind on today’s special species – one of the most loved and admired of the sea creatures of the Bahamas archipelago. If they go, we humans may not be far behind (but at least we won’t have stomachs full of plastic trash).

TURTLES: HAPPY TOGETHER!

Credits: Melinda Riger, Adam Rees, Virginia Cooper – and to all for their work in revealing the wonderful world beneath the ocean waves

ROCK BEAUTY: BAHAMAS REEF FISH (52)

May 10, 2019 by Rolling Harbour

ROCK BEAUTY: BAHAMAS REEF FISH (52)

I last featured the cheerfully-coloured Rock Beauty Holacanthus tricolor 2 or 3 years back. Time has passed; new photos exist; new people have signed up to follow this eclectic menagerie (thank you both). Time for another look at these beauties, which also happen to be cuties.

Look at the little guy above – posing for Pixar, adorably hoping to star in Part 3 of the Nemo / Dory trilogy

These fish are a small species of angelfish. Seen swimming around the reefs they are unmistakeable, not least because of their bright yellow hi-viz jackets, remarkable blue eyeliner and blue-black lippy.

Rock Beauties look like prime candidates for anyone’s aquarium, but their picky dietary requirements and tendency for aggression make them unsuitable.

They are highly specialised feeders, needing marine sponge in their daily diet. They are also prone to chase their tank-mates and nip them. On balance, they look more fetching nosing about the coral anyway.

WHAT DO JUVENILES LOOK LIKE?

Juvenile rock beauties are cute mini-versions of the adults, only more yellow and with yellow lips. In some development stages, they have a smart blue circle around the dark patch on their sides (bottom image).

NOTE Rock Beauties have no known kinship with Chrissie, Debbie, Lita, Joan, Jennifer, Stevie, Madge and the rest of the accredited ‘Rock Beauties aka Chicks’

NOT A TRUE ‘ROCK BEAUTY’ (no offence, Lita)

A TRUE ROCK BEAUTY

Credits: Melinda Riger, Grand Bahama Scuba; WP

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

April 19, 2019 by Rolling Harbour

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

HOW DO THEY FEED?

Diagram of adult solitary tunicate

WHAT DOES ‘TUNICATE’ MEAN?

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

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

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

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

‘REEF ENCOUNTER’ 1: GRAY ANGELFISH

April 4, 2019 by Rolling Harbour

‘REEF ENCOUNTER’ 1: GRAY ANGELFISH

Today I learn from a cheery message from WordPress that my illustrated ramblings have been going on for exactly X years, where X is greater than 5 but less than 10. Time to start a new theme: channelling my inner Noel Coward, I am introducing a new mainly pictorial series provisionally called ‘Reef Encounter’. All the awesome beauty of reef life will be here.

In the past I have posted about GRAY ANGELFISH, one of three kinds of angelfish found in the northern Bahamas. Today, I am featuring some more recent images of these pretty creatures. Note in particular the striking shape and colour of their mouths, the blue being found also on the fin edges at the back.

On this otherwise gray fish, you’ll also find touches of yellow on the face and the edges of the front fins. In the header image there’s another little fish in the bottom right corner. Not a baby angelfish, but a FOUR-EYED BUTTERFLYFISH – a species that will feature in own right in due course