QUEEN TRIGGERFISH AND GOOD RIDDANCE TO MARIA

September 22, 2017 by Rolling Harbour

QUEEN TRIGGERFISH AND GOOD RIDDANCE TO MARIA

I can think of no sensible connection between the colourful yet undoubtedly strange and grumpy-looking looking queen triggerfish Balistes vetula, and a hurricane. However, Hurricanes Irma and Maria have been rightly dominating the news and everyone’s thoughts for nearly 3 weeks now. And most of the recent posts from Rolling Harbour, for that matter. It’s not been a great time for looking at the birds, beasts and fishes. So, as Maria drifts eastwards and away from the Bahamas into the open ocean, it’s time for a splash of colour – and a fish I have not featured before.

Hurricane Maria tracking at 11.00 EST on Sept 22

The queen triggerfish, sometimes known as an Old Wife, is an Atlantic reef fish. This species is sometime fished for as game, and I know that a few have been taken from off the rocks at the south end of Delphi beach over the years – though perhaps not exactly on purpose.

This fish typically is coloured with shades of blue, purple, turquoise and green with a yellowish throat, with pale blue lines fins on head and fins. It’s minor superpower is to be able to change its coloration to some extent to match its reef surroundings and assist camouflage. Its favourite food is the sea urchin.

Let’s hope this is the last post to feature anything about hurricanes for a good long time, as we think of all those still struggling to make sense of the terrible destruction they have recently experienced – in some places, twice over.

Credits: Melinda Riger / Grand Bahama Scuba; Mark Peter, Wiki; Clark Anderson / Aqua-images

CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS

August 29, 2017 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 them.

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.

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

BAHAMAS REEF FISH (38): SPOTFIN BUTTERFLYFISH

August 22, 2017 by Rolling Harbour

BAHAMAS REEF FISH (38): SPOTFIN BUTTERFLYFISH

Butterflyfishes are a large family of mainly colourful small fish somewhat like mini-angelfish. The spotfin butterflyfish (Chaetodon ocellatus) is one of several types of butterflyfish found in the western Atlantic Ocean; and one of half a dozen or so you are likely to see nosing around the coral reefs of the Bahamas.

The name ‘spotfin’ derives from the dark spot on the dorsal fin. At the front end, there is a distinctive black vertical stripe that passes right through the eye. Combined with the vivid colouring, predators are in theory confused or warned off. The spotfin’s superpower (on a modest scale) is that at night, a change of appearance occurs in adults. The dark patch on the dorsal fin increases in size, and dark bands appear on the body. This seems to be in order to provide further protection during the darker hours.

The spotfin above has an isopod attached to it, a type of crustacean with a segmented body. Primitive fossils of these creatures have been dated back some 3m years. Want to know want this one is up to? These things “are mostly external parasites of fish or crustaceans and feed on blood, having piercing and sucking mouthparts and clawed limbs adapted for clinging onto their hosts”.

Soldierfish photobombs a spotfin. Or maybe it’s vice versa?

Reading about this particular species of butterfly fish, I discovered that the spotfin “is very common and very hard to maintain in a tank” – as if the two facts are somehow connected. So might they be coarse or vulgar, and thus unsuitable companions for better bred and perhaps sensitive aquarium fish? As it turns out, it may be because they are vulnerable to predation, and so can coexist only with peaceable tank friends.

Spotfins are perfectly happy swimming upside down; and their party trick apparently is to rise to the surface and squirt a jet of water in the air. Sadly, I couldn’t come up with a photo of this…

LONGSNOUT BUTTERFLYFISH

REEF BUTTERFLYFISH

Credits: All fab photos by Melinda Riger / Grand Bahamas Scuba

ROCK BEAUTY: BAHAMAS REEF FISH (37)

July 28, 2017 by Rolling Harbour

ROCK BEAUTY: BAHAMAS REEF FISH (37)

The Rock Beauty Holacanthus tricolor is 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. They featured near the start of this series HERE, and a recent online search (for something else completely, as is often the way) reminded me to give them another swim round Rolling Harbour.

In addition to the hi-viz-and-eyeliner combo, the Beauty above has chosen a fetchingly cheeky pair of matching ISOPODS (crustacean parasites) to adorn its face – possibly the piscine equivalent of a tat…

Rock Beauties look like prime candidates for anyone’s aquarium, but their 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 (including the lips). In some development stages, they have a smart blue circle in the middle of the dark patch on their sides (bottom image).

NOTE Rock Beauties have no known relationship to Chrissie, Debbie, Lita, Stevie, Joanna, 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,Wiki

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN

July 18, 2017 by Rolling Harbour

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN

Hawksbills on their own, nosing around the colourful coral reefs of the Bahamas, are a beautiful sight. I don’t want to overdo the religious tendency of the title, but they are indeed wonderful to behold. Add FRENCH ANGELFISH and a QUEEN ANGELFISH and it’s as close to perfection as a reef scene gets. Click on the links above for more pictures and details about the two angelfish species seen here with the turtle. As ever, Melinda Riger was ready with her camera to capture these great images.

This astonishing photo was of course achieved by carefully balancing a GoPro on the turtle’s back, wrapping duct tape around it, and pressing ‘go’ (camera and turtle simultaneously). **

** This is not true. It’s just a cleverly shot turtle’s-eye view as it forages on the reef

This short video shot by Melinda’s husband Fred of a turtle ‘loving’ the camera is one of those wildlife events that cannot be predicted… but when it happens, it’s frankly a bit of a scoop.

OPTIONAL MUSICAL DIGRESSION

As I was writing this, an earworm started up and grew insidiously in both ears and then inside my head… the dread words “Elenore, gee I think you’re swell”. Followed by “so happy together…”. And then “she’d rather be with me…” Yes, I’ve now got TURTLES in my head, the (?long-and-hitherto-forgotten) band from the second half of the 60’s, with their cheery anodyne soppy-poppy love songs. And dammit, they’ve stuck… Here’s a reminder for those whose memory I have jogged. For anyone under, say, 75, step away from this area. Nothing to hear here.

Credits: Grand Bahama Scuba: all photos – Melinda Riger & video – Fred Riger; Turtle music – someone else’s music collection, not mine, honestly… (oh dear another lie I am afraid – cred gone)

BAHAMAS REEF FISH (36): REEF BUTTERFLYFISH

July 6, 2017 by Rolling Harbour

BAHAMAS REEF FISH (36): REEF BUTTERFLYFISH

Butterflyfishes come in several varieties in Bahamian waters; and there are more than 120 species worldwide. Not so long ago I wrote about the LONGSNOUT variety, also known as the “Butterbun”. Now it’s time to take a look at the Reef Butterfyfish.

In some ways butterflyfishes resemble small angelfishes – adult Reefs are just a few inches long. As the name suggests, these are creatures of the reefs, and of shallow waters. As one might expect, these colourful fish are popular for aquariums (or, strictly I suppose, aquaria).

Butterflyfishes have interesting spawning patterns. They release large numbers of buoyant eggs into the water. These become mixed in with plankton and suchlike, and float where the tides take them until they hatch. Then, most unusually, they go through a larval stage when they are covered by bony material, which they lose as they mature. This is known as an ‘armoured’ stage, which I can only assume is to provide protection to the tiny fry – perhaps by making them crunchy and unappetising. I’ve been trying to find a usable illustrative drawing, without success so far.

OPTIONAL MUSICAL DIGRESSION

In some parts of the world the butterflyfish is called a BORBOLETTA, which is Portugese for ‘butterfly’. It is also the title of Santana’s criminally underrated sixth album (1974). For sure it’s no 1st, Abraxas, 3rd or Caravanserai… but if you can tolerate the man’s move to ‘jazz-funk-fusion’ – maybe John McLaughlin had a hand in that – there is much to enjoy. There’s less searing guitar and there’s some strange ‘soundscape’ stuff that’s maybe not to everyone’s taste. But still – it stand up pretty well in comparison with some of the later Carlos creations where a certain tiresomeness began to creep in and some tracks are (IMVHO) not really listenable-to. Anyway, the recently released (2016) Santana IV is a welcome return to the good old days, and the good old team.

Here’s ‘Promise of a Fisherman’ – 8 minutes of Santana, from which you can judge the direction he’s taken by Album 6…

All photos by Melinda Riger of Grand Bahama Scuba – mainstay, with Adam Rees, of the underwater photos I use, what with me being a feeble swimmer and all. Tip o’ the Hat to Carlos, who I have even managed to see Live a couple of times.

REDSPOTTED HAWKFISH: BAHAMAS REEF FISH (35)

June 23, 2017 by Rolling Harbour

REDSPOTTED HAWKFISH: BAHAMAS REEF FISH (35)

The redspotted hawkfish (Amblycirrhitus pinos) is one of a number of species of hawkfishes found worldwide. This one is found on the sub-tropical and tropical reefs of the Western Atlantic, and is therefore a fish you might see when out snorkelling or (more likely) scuba-ing in the Bahamas. These are small creatures – adults are unlikely to exceed 4 inches in length.

There’s not a whole lot else to report about them. They have no medicinal superpowers, for example, nor wickedly toxic spines. A quick scroll through the highways and byways of the interweb reveals that redspotted hawkfish are considered (rightly, I think) to be attractive, tend to be shy, enjoy perching on coral ledges, and are generally benign, except to smaller fishes to which they may show aggression or – worse – an appetite.

As you might predict, these pretty little fish are popular in the aquarium trade, where on any view they should be kept safe from predators. But maybe captivity is a little limited in opportunities for travel and exploration. They can be bought for (I just checked) $29.99. Or else left alone on a reef to take their chances.

Photo Credits: Melinda Riger / Grand Bahama Scuba, with thanks as per…

JAW-DROPPING: GROUPERS AT THE CLEANERS

June 6, 2017 by Rolling Harbour

Grouper at cleaning station - Melinda Riger @ GB Scuba

JAW-DROPPING: GROUPERS AT THE CLEANERS

In some of these photos you’ll notice tiny fish attending to the grouper. These are CLEANERS and they are an essential part of the bodily and oral hygiene routine for larger fish species. The big fish call in at so-called CLEANING STATIONS, where the tiddlers remove parasites and dead skin, and polish up the gills. They will even enter the fish’s mouth to pick bits from between its teeth – the deal being that they will not be eaten. This mutually beneficial arrangement is called ‘cleaning symbiosis’ and is carried out by (for example) gobies, wrasses and cleaner shrimps.

Pederson’s cleaner shrimps and cleaner wrasse

Some of these photos show groupers with open gills as well as open mouths, an invitation to the cleaners to do their work. I’d intended to write about how and why gills work but I’ve thought better of it. There’s a lot of detail about chemical exchange involved that, when I looked more closely, seemed rather dull… and therefore outside the remit of this blog, which includes trying to avoid ‘dull’. If you really want to know more, Wiki has a good article HERE. Good luck with that….

Credits: All photos Melinda Riger, Grand Bahama Scuba

ONE GOOD INTERN DESERVES ANOTHER (Part 1)

June 1, 2017 by Rolling Harbour

ONE GOOD INTERN DESERVES ANOTHER (Part 1)

Four years ago a young English friend of ours, Oscar Ward, was lucky enough to be offered an internship with the Bahamas Marine Mammal Research Organisation (BMMRO). At the time, he was post-school, and waiting to start a degree course in marine biology at university. He had no practical experience at all, so he had to progress from the menial tasks (scraping barnacles off the bottom of the research boat) to the more adventurous (whale poop-scooping) to the scholarly (collection and analysis of samples and data, including audio file matching of whale calls for identification). The need for hard work, concentration and accuracy were made clear from the outset… and as you will see, Oscar’s short internship has stood him in very good stead during his university course.

Oscar weekending at Gilpin Point – self-sufficient

From a promising start on Abaco, and with 2 year’s study behind him, Oscar is currently spending the 3rd year of his 4-year course in Australia, working with The Australian Institute of Marine Science. He has been involved in a number of complex projects focussed on corals and reef life – as we all know, a matter of huge concern – and the projections for the future of the reef systems in a time of warming seas and raised acid levels. Oscar also assists PhD students, for example examining the damaging effects of parasitic worms on coral; and the effect of changing light conditions on corals.

Much of Oscar’s time has been spent doing fieldwork. Often he is at sea, monitoring and collecting samples in the Southern Great Barrier Reef, diving two or three times a day. This work is often carried out in restricted or preservation zones, and with ever-present manta rays, sharks and sea turtles around him.

Right now Oscar is involved with the investigations into the recent bleaching events, work that is at the forefront of serious concern for the GBR and far beyond. I have recently corresponded with him – he has definitely not forgotten that his grounding for the fieldwork and studies that he is engaged in – and very likely his career – came from his time on Abaco and the lessons he learned during his time with the BMMRO at Sandy Point. (In part 2: another good intern, currently at Sandy Point)

All photos: Oscar Ward (the header image is taken from a research vessel – no idea how, maybe a drone with fish-eye lens?)

‘CUDAS: “WHAT BIG TEETH YOU’VE GOT…”

May 16, 2017 by Rolling Harbour

‘CUDAS: “WHAT BIG TEETH YOU’VE GOT…”

Or, if not exactly big then lethally lacerating. Their sharp fangs are all different sizes, which gives more of a mincing effect than a clean bite. Then there’s the underbite, involving more mincing. And the fact that the teeth are set at different angles. That’s a third mincing effect. Prey in those strong jaws? No chance.

Three -way mincing machine. Avoid.

Teeth? Enough dentition already. It’s impossible not to admire these lean, mean eating machines as they glide around in their natural environment. The photos below are designed to redress the balance a bit. Sinister, yes. But mighty fine fish, without a doubt.

All photos: Melinda Riger, Grand Bahama Scuba, with thanks as ever for her terrific photos

WTF? (WHAT’S THAT FISH?) 13: THE ROUGHHEAD BLENNY

May 8, 2017 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 13: THE ROUGHHEAD BLENNY

The WTF? series has looked at a number of bizarre reef denizens, and this little fish is certainly that. For a start, its ‘correct’ name is Acanthemblemaria aspera, an excellent challenge for saying 10 times very quickly **. And the name blenny comes from the Greek word for ‘slime’, quite enough to make the poor creature a laughing-stock in the reef community.

There are in fact several hundred blenny species and subspecies around the world. The roughhead is one of the most commonly found in western Atlantic subtropical and tropical waters. These are burrowing creatures, and they find holes in the nooks and crannies of coral reefs – and indeed in the coral itself. Brain coral seems to be a preferred location. Mollusc shells are another. Or they may just bury themselves in the sea floor.

The ‘roughness’ of head refers to the whiskery appendages (cirri) on a blenny’s blunt bonce – slender tendril or hair-like filaments. The word cirri is the plural version of the wispy high altitude cirrus clouds that streak the sky. These tendrils are shown clearly in some of the photos here, despite the tiny size of the fish (± 1 inch).

THESE GUYS LOOK A BIT PRIMITIVE, AM I RIGHT?

To be precise – as far as is possible – blennies can be dated back to the Paleocene Era (or is it an Epoch?). This spanned a period 66 to 56 million years ago – around the time of the formation of the Rolling Stones.

You can find out more about roughheads in this excellent eHow video I came across after I’d written this post, to which I should now add that there is considerable colour variation in this subspecies, as you may already have noticed…

** You can also try this with ‘Red Lorry Yellow Lorry’. Yes I know. Maddening, isn’t it. You can’t stop now you’ve started. Sorry…

Credits: all photo, Melinda Riger; video, eHow

OCTOPUSES: WORTH LEARNING TO SCUBA FOR?

April 24, 2017 by Rolling Harbour

OCTOPUSES: WORTH LEARNING TO SCUBA FOR?

If I had to give a single reason for learning to scuba, watching an octopus would be very near the top of a long list. It’s never going to happen for me, of course – I have about 17 excuses lined up just in case anyone should ask me to try it. But still. One can dream…

Meanwhile, I can luckily rely on an experienced professional to get the shots. Here are a few great octopus photos taken by Melinda Riger of Grand Bahama Scuba – perfect examples of an excellent reason for chucking aside the snorkel and doing something a bit more adventurous. Maybe…

BLUE TANG AS REEF FILM STAR

April 19, 2017 by Rolling Harbour

BLUE TANG AS REEF FILM STAR

Last summer, the big motion picture sensation for the bird world was, of course, Pixar’s ineffably adorable creation, Piper – the ultimate ‘Chick Flick’. This little ball of cartoon fluff was not, as some thought, based on a piping plover but on a sanderling – a type of sandpiper (clue in name). This 6 minute ‘short’ preceded the main event, the hugely popular Finding Dory. You can read all about the film Piper and the birding aspects of the film HERE.

Blue Tang, Bahamas (Melinda Riger / Grand Bahama Scuba)

Finding Dory is not about a fish of the dory species, of course. Voiced by Ellen DeGeneres, Dory is in fact a species of surgeonfish Paracanthurus, the familiar blue tang found on the reefs of the Bahamas. To see these fish in Abaco waters, Fowl Cays National Park is always a good bet.

Dory can be identified as a maturing juvenile: blue, with a yellow tail. In due course – in time for the sequel film – she will become blue all over, with perhaps the odd flash of yellow (see photos above).

In real life, a baby blue tang is in fact entirely yellow, except for blue rings around the eyes. In Pixarland, however, Dory is just an adorbs miniature version of her youthful self.

Blue Tang are lovely to watch as they cruise round the reefs, sometimes in large groups. Their colouring ranges from pale to dark blue. However, these are fish that are best looked at and not touched – their caudal spines are very sharp. When the fish feels in threatened, the spine is raised and can cause deep cuts, with a risk of infection.

Still from a crummy video taken at Fowl Cays some years back to illustrate a group of blue tang

Blue tangs are inedible, they apparently smell unpleasant, and they can cause ciguatera. However they are popular in the aquarium trade. This is a distinct downside of highly successful films such as Finding Nemo and Finding Dory. In defiance of the well-meant and broadly ecological message of both films, the trade in clown fish and to a lesser extent blue tang was boosted by their on-screen portrayal as adorbs creatures desirable for the entertainment of mankind… ‘Nuff said.

Credits: All excellent photos by Melinda Riger / Grand Bahama Scuba; one pathetically bad still from a low res video, me; cartoons purloined from an online aquarium somewhere or other

DUSKY DAMSELFISH: BAHAMAS REEF FISH (34)

March 31, 2017 by Rolling Harbour

DUSKY DAMSELFISH: BAHAMAS REEF FISH (34)

The dusky damselfish Stegastes fuscus is one of a number of damselfish species found in Bahamian waters. These small reef fish, in adult form, are dark coloured as their name suggests. Their appearance is brightened by having distinctive blue edges to their fins.

These fish feed mainly on algae, with a preference for red. They top up their diet with small invertebrates. Their value to the reef is that their feeding patterns help to prevent coarser seaweeds from becoming dominant in areas where these are prevalent.

Like many damselfish, the dusky is a territorial species, guarding its chosen area of seabed and the food sources within it by repelling intruders – often seeing off far larger algae-grazing fishes such as parrotfish and wrasse. Yet besides their aggressive traits, they are also rather cute, as photo #2 shows!

All photos: Melinda Riger / Grand Bahama Scuba

COMING HOME: IT’S ELVIS (THE SQUIRRELFISH)

March 14, 2017 by Rolling Harbour

Being ‘on-island’ right now, I don’t get so much time to write stuff. To everyone’s relief, I guess (including mine). So for a while I’ll post some individual pics that particularly appeal to me. Elvis the squirrelfish (featured in a previous post) has now upgraded to a more spacious and frankly rather posher address. And in he goes…

FORAYS WITH MORAYS (4): EXPRESSIVE FEATURES

March 10, 2017 by Rolling Harbour

FORAYS WITH MORAYS (4): EXPRESSIVE FEATURES

Time to return to those extremely expressive characters of the coral reefs, moray eels. Specifically, some green morays. One hesitates to anthropomorphise or ‘project’ human emotions onto creatures but with some species it’s hard not to do so. Following Mr Grumpy (or perhaps Mr Sad) in the header image, here are some close-ups of morays appearing to express their emotions, from happy to downright furious… Eels featured here include Judy and Wasabi, and I remind myself that the human habit of naming familiar wild creatures is itself a (perfectly harmless) form of benign animism. Exactly as with the regular banded piping plovers featured elsewhere in this blog that overwinter on Abaco’s beaches, such as Harry Potter, Bahama Mama and the delightfully-named Felicia Fancybottom…

Happy and contented?

Something on my mind…

Slightly amused?

Pretty funny, actually

Ha ha…! Hilair!

Watch it. You are beginning to bug us, Mr Harbour, with your stupid captions

ANGRY. BACK OFF… NOW!!!

THE NEXT POST WILL BE FROM ABACO HQ NEXT WEEK

Credits: All morayvellous photos, Melinda Riger / Grand Bahama Scuba except 6, Virginia Cooper / Grand Bahama Scuba

BLUEHEAD WRASSE: PRIVATE LIFE LAID BARE

February 14, 2017 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 of 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. And, unfairly, some species that are content to let cleaner gobies runtle 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
The main threat to the species is coral reef degradation or destruction
The bright colours invite aquarium use, but the trade is not a significant one

** Some sources suggest some are born male and remain male. I’m not sure which is right

A juvenile bluehead (with feather-duster worms) – 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 is the subject of extensive scientific research, not all of which I have read since I decided to write about the species last night. Like 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 even 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 (as it were) is signalled by colour changes
This behaviour is similar to that seen in many city centres in a Saturday night
The smaller fish have one bonus – their sperm count is higher than a dominant male
Prozac tests have shown that the drug reduces a dominant male’s aggression

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. Maybe it’s not a BW at all. Or it’s a different type of fish completely. Or 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

A bluehead wrasse passes the time of day with a grunt

WONDERS OF THE DEEP: FROM SUBLIME TO… THE OTHER THING

January 19, 2017 by Rolling Harbour

WONDERS OF THE DEEP: FROM SUBLIME TO… THE OTHER THING

It’s a statistically proven fact (and not, in any way, a ‘post-truth’ proposition) that no one has ever had a bad thing to say about seahorses. Indeed, some love them too much and consume them – see HERE for threats to seahorse populations in some areas of the world.

Sometimes they are easy to see. The header image shows an orange seahorse curling its tail round green weed on pink coral – hard to miss. Yet sometimes it may be quite difficult to see the little creatures against their chosen background.

These guys are, I think, for their size among the most sublime of all underwater creatures. I use the word in the strict historical sense “of very great excellence or beauty, exalted, awe-inspiring, majestic, magnificent, glorious.” Not just to mean “nice”.

In contrast, there are some undersea creatures that inspire… not awe exactly, but maybe an amused respect that so wonderful and bizarre a creature can exist in our oceans, in some cases only a few feet below the surface. Here are two examples of what I mean.

This is a BATFISH. It was an early shoo-in for my “WTF? (What’s that Fish?)” series, and you can read all about them and their ways HERE. Of all the creatures I have featured on this blog, this is by some distance the oddest…

frogfish-anglerfisch

…except for its companion in oddness, the FROGFISH. This was next in the WTF? series, and the creature is, if anything, even stranger. You can read all about these critters HERE, where you will learn inter alia about their superpowers – any one of which you might like to have yourself. There are plenty of photos, and videos too.

FROGFISH SUPERPOWERS

Invisibility Cloak
Irresistible (and, to their prey, Fatal) Attraction
Buoyancy Control
Shapeshifting

I do not court controversy, recognising that people following this site, or maybe stumbling across it by mistake and lingering, reach their views on natural history from different directions. But these strange and fascinating species exist and thrive in their own particular and ingenious ways – it doesn’t really matter how or why they are as they are. The bats and the frogs are high in the list of the least conventional of undersea creatures, and if they are not exactly sublime in a seahorse sense, can we just agree that they are awesome?

Photo Credits: Adam Rees / Scuba Works; Melinda Riger; Alex Konahin (seahorse gif)

WATCHING NURSE SHARKS: BE PATIENT…

January 12, 2017 by Rolling Harbour

WATCHING NURSE SHARKS: BE PATIENT…

I last took a look at nurse sharks nearly 3 years ago HERE. Time to revisit these creatures. Indeed, time for a close-up look. If you want to know more about this fascinating species, just click the link above.

The two strange items hanging down from the upper lip are sensory barbels

This side-view shows the shark’s relatively small mouth (for a shark anyway)

Admire the extraordinary texture of the the skin; and the tiny evil eye. Click or – better – double click on the image and you will see that the skin is in fact tessellated, made up of a mosaic of tiny squares and near-squares**

This one is a baby nurse shark

A juvenile nurse shark with a couple of grunts. Note the youngster’s paddle-like fin

Head, mouth, jaws and teeth

SO, THEY ARE SHARKS – ARE THESE GUYS DANGEROUS?

Not really, no. They aren’t looking to pick a fight; and they are not as territorially aggressive as the ‘bitey’ sharks are (or can be). These slow-moving bottom-dwellers are generally harmless to humans. However, they can be huge—up to 4 metres —and have very strong jaws filled with thousands of tiny, serrated teeth. They will bite defensively if stepped on or bothered by divers who assume they’re docile. [As I said previously, “there are recorded instances of injuries caused to divers who have tried to pull nurse sharks by the tail. And serve them right, I say. Treat them with patience and respect!”]

**FUN FACT

M.C. ESCHER (the inspiration for Mr Hammer) was the master of tessellation in art. Click the link to explore the dedicated website. Maybe, sensationally, one day a shark will be found with skin like this… (Alert reader: “Actually, I think it most unlikely…”)

Credits: field photos by Melinda Riger, Grand Bahama Scuba; Wiki for the 4 mouth images & the Escher

WTF? (WHAT’S THAT FISH?) 12: THE TRUMPETFISH

December 12, 2016 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 12: THE TRUMPETFISH

It’s been a while since the previous post in the WTF? series, dedicated to the unusual or downright weird marine creatures that, when you see them swim into in the frame of your mask, prompt the involuntary exclamation “WTF?” (What’s That Fish?). Now, in all its glory meet… The Trumpetfish. These long piscine pipes are in no way related to the President-Elect and his tank of pet fish, but perhaps more explicably to seahorses and seadragons.

Trumpetfishes Aulostomus maculatus are as happy to swim upright as more conventionally, which helps them to blend in with vertical corals and sponges on the reefs in the tropical waters of the western Atlantic. Adults may grow to 3 foot long or more. These creatures come in a variety of colours – shades of red, orange, brown, green and yellow.

At the end of the fish’s long snout – see how far back the eyes are set – is a small mouth. Here’s how a trumpetfish goes about catching its prey (mostly small fishes):

Slowly swimming or drifting to a target from behind, and sucking it into its mouth
Staying suspended in the water, motionless, and waiting like a malevolent stick for a passing wrasse or similar to get too close
Swimming alongside larger fishes, which camouflages its presence and enables it to ambush small fish as they pass
More generally, the trumpetfish has some ability to change its colour to blend with its surroundings – both a defensive as well as an attacking advantage

The very excellent Peppermint Narwhal recently produced a series of posters in appreciation of particular species – and trumpetfishes and their kin in the Order syngnathidae were honoured. The PN’s cheerful website is well worth checking out for the sheer diversity of their ideas.

MUSICAL NOTES

We are beginning to collect the makings of a decent orchestra here. The trumpetfish has a relative, the cornetfish, elsewhere in the world. The remarkable GUITARFISH has already featured in the WTF? series, as has a species of BASS, the Harlequin. And – hey! – what about the spotted DRUMFISH to lay down the beat? Maybe I need to compose a little jingle featuring these one day…

Credits: Melinda Riger (Grand Bahama Scuba); Adam Rees (Scuba Works)