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

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

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

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN

January 3, 2019 by Rolling Harbour

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN

Pliny the Elder (CE 23–79) was one of the earliest naturalists, besides being a philosopher, author and military commander. He wrote Naturalis Historia (Natural History), a wide-ranging work that became a model for later scholarly works, including forms of Encyclopedia. And, as he so nearly wrote, ‘si non amas testudines, vacua anima tua est’ (he that loves not sea turtles, has an empty mind)*.

Hawksbill turtle grazing while a French angelfish looks on Hawksbill Turtle with French Angelfish, Bahamas (Melinda Riger / G B Scuba)

There can be few better ways to start the New Year than with some gorgeous Hawksbill Turtles Eretmochelys imbricata, plus a sprinkling of turtle facts to give 2019 a good push into orbit. Fortunately still available in Bahamas waters, the continued existence of Hawksbills is under serious threat. Make the most of your opportunities.

Guesstimates of the world Hawksbill Turtle population suggest that there are 5 main groups in the oceans, with few enough individuals – especially breeding females – to warrant an IUCN listing of the species as critically endangered
I doubt that many will forget that the next IUCN category is… extinct (≠ ‘fun fact’)
The largest Hawksbill colony in the world nests on an island in Queensland Australia
Turtles leave the sea to lay eggs in a hole dug on the beach, before returning to the sea.
The eggs hatch after c60 days… the turtlings emerge and are then on their own
Hawksbills are omnivorous, mainly eating sponges (& immune from sponge toxins)
They also eat sea anemones, mollusks, and jellyfish
Their grazing lifestyle is an important component of a healthy coral reef ecosystem

Though their shells are hard, Hawksbills are prey for sharks, crocodiles, octopuses and “the biggest predator of all, humans“.
Despite international Hawkbill protection and conservation measures, they continue to be illegally hunted – including, in some places, for food.
Their lovely shells – tortoiseshell – are illegally traded for use for ornaments and jewellery
Japan makes its own rules (as with whales) for traditional & no doubt research purposes
‘Tortoiseshell’ is the illegal item most frequently confiscated by custom officials
Reef and beach degradation, development, light pollution (confuses the baby turtles trying to paddle to the sea), ocean pollution / marine debris, and illegal practices are among the greatest dangers to the survival of the species. All are caused, directly or indirectly, by you and indeed me

Credits: wonderful photos by Melinda Riger / Grand Bahama Scuba (1, 2, 5) & Adam Rees / Scuba Works (3, 4, 6); Widecast; Nature Conservancy; OneKind Planet

* Do not believe this – I invented it. The pretentious quote that props up the other stuff, that is – all the rest is true…

GREEN TURTLES & TURTLE AWARENESS ON ABACO

June 15, 2018 by Rolling Harbour

GREEN TURTLES & TURTLE AWARENESS ON ABACO

There’s something slightly unsettling about the perspective of the header image, with foreshortening suggesting that the turtle is actually a gigantic creature with a tiny diver swimming close to it…

I don’t seem to have given green turtles much space in the past, the most frequently photographed (and therefore featured) species being the hawksbill. This post is both to right the wrong, and to provide some information about the species.

Friends of the Environment has produced an interesting short guide to the sea turtles of the Bahamas. One of the many facts included is that 5 of the 7 sea turtle species in the world can be found in Bahamian waters. The turtle protection law is also given – also the way to report turtle nests so they can be watched and protected.

The 4 main species are the hawksbill, green, loggerhead and leatherback. The 5th and lesser known one is the Olive Ridley turtle. The differences between most of these is considerable, as can be seen from this IUCN-produced Identification Chart (credits as shown).

Another useful source of information for green turtles is this extremely well produced poster illustrated by the excellent Dawn Witherington, who has somewhat (and deservedly) cornered the market with this kind of large-scale infographic. The sea turtle series is so helpful that I have dedicated a whole page to them HERE. Dawn also created the LOXAHATCHEE poster series covering such topics as Lionfish, Sea Grasses, Land Crabs, Bonefish, Coral Reefs and more

All photos: Adam Rees Photography, with thanks for use permission here and elsewhere

WTF? (WHAT’S THAT FISH?) 15 PORCUPINEFISH

April 12, 2018 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 15 PORCUPINEFISH

The porcupinefish Diodon hystrix falls into the general category ‘pufferfish’, though the particular species named PUFFERFISH are distinct in their own right. There are other similar species – e.g. balloonfish, blowfish and burrfish – with which there is scope for confusion. The relationship is something like this: all porcupinefish are pufferfish (in a broad sense); but not all pufferfish (in its species sense) are porcupinefish.

Porcupinefish are slow-moving reef dwellers and like their puffer cousins, they can inflate themselves by ingesting water, turning them into spiny balloons. This defence mechanism is a response to threat and works in two way: only predators with large mouths would consider them a meal; and even then they have to deal with the spines that become prominent when the fish is bloated.

I’VE HEARD PUFFERFISH ARE POISONOUS? WHAT ABOUT THIS GUY?

Good question. Checking it out, I’ve found some contrary statements about this. The truth seems to be that unlike pufferfish, they do not produce toxic secretions from their skins, so are not poisonous to touch (if you must**).

However porcupinefish do contain powerful (neuro)toxins in their internal organs and are best not eaten – though in some parts of the world they are considered a minor delicacy. They may also suffer the ignominy of being dried in their inflated state and sold to tourists as novelties – with lightbulbs inside for added amusement value.

ARE PORCUPINEFISH FAMOUS IN ANY RESPECT?

Indeed they are. They had the honour of being recorded by Charles Darwin. He gives a surprisingly long account of this creature, encountered during his renowned voyage on the Beagle. It clearly fascinated him. I’ve ‘ripped’ the relevant passage (open source – it’s ok) and turned it into an eezi-reed pdf if you want to check out Darwin’s careful observations in more detail:

THE VOYAGE OF THE BEAGLE – CHARLES DARWIN

WAIT! ISN’T THERE A MORE RECENT CLAIM TO FAME?

Yes! In ‘Finding Nemo’, Bloat the Porcupinefish was part of the ‘Tank Gang’ in a dentist’s office. He had an encore in the closing credits of ‘Finding Dory’. Enough of fame already. Here’s a 50 second video demonstrating the puffer / porcupine distinction.

PUFFERFISH

WTF? SERIES PAGE

MONSTERS OF THE DEEP

Photo Credits: Melinda Riger (1, 2); George Parilla (3); Virgini Cooper (4); Bernard Dupont (5); Adam Rees (6, 7); Video, ‘AquariumKids’ (I do high-powered research, see?)

**Incidentally, it’s apparently not considered an act of animal kindness to catch them / scare them so you can have the pleasure of watching them blow up

WTF? (WHAT’S THAT FISH?) 14: ARROW CRABS

January 16, 2018 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 14: ARROW CRABS

It’s been a while since the last in the WTF? series, which 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.

Feather-duster worm (Melinda Riger / G B Scuba)

Arrow Crab Meal

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

HAWKSBILL TURTLES: DIVERS VIEWS…

October 2, 2017 by Rolling Harbour

HAWKSBILL TURTLES: DIVERS VIEWS…

Daydream for a moment. Imagine that you had a different occupation. And your new one involved daily contact with spectacular wildlife underwater (this assumes you can swim – debatable in my case). And access to some upmarket camera equipment. And the ability to use it effectively. Oh, and use of a reliable boat. And some sea.

Say, for example, you joined a dive operation. Then the chances are very high that these wonderful creatures would be a part of your daily 9-to-5.

You wake up with a start. Oh no! Half an hour gone, and that crucial email still half-written… Where did the time go?

All gorgeous turtles taken by Adam Rees of Scuba Works (slogan: “Land is so overrated”) in the course of his everyday working life. Some people, eh?

TURTLE BREEDING SEASON & A SMALL POEM TO PONDER

May 1, 2017 by Rolling Harbour

TURTLE BREEDING SEASON & A SMALL POEM TO PONDER

The turtle lives ‘twixt plated decks
Which practically conceal its sex.
I think it clever of the turtle
In such a fix, to be so fertile.

Anyone unfamiliar with the works of OGDEN NASH (1902 – 1971) would do well the check out his inimitable poetry, in which he takes extreme liberties with both rhyme and scansion to great comic effect. The poem above is a good example of Nash’s neat way with words. It always makes me laugh, anyway. So simple, looks so easy, but a very difficult trick to pull off consistently as Nash effortlessly does.

As the turtle breeding season moves forward, I though this would be a good time to show a few of the great turtle photos taken by Adam Rees of ‘Scuba Works’.

All photos: Adam Rees / Scuba Works

PREHENSILE TALES FROM THE REEF (3): SEAHORSING AROUND

April 7, 2017 by Rolling Harbour

PREHENSILE TALES FROM THE REEF (3): SEAHORSING AROUND

It’s Friday at last. It’s springtime. A spirit of benign goodwill is evident in the vicinity of Rolling Harbour. Seahorses are irresistible. Don’t even try to pretend they don’t make you smile. Hippocampophobia is an affliction that, as yet, has never been diagnosed in a human being – for whom fear of beards, clowns and the number 5 (quintaphobia) are known medical conditions. Immerse yourself with these little creatures – and then have a good weekend.

All fantastic hippocampi photos: Adam Rees / Scuba Works

SAWFISH: UNIQUE LIVE BIRTH FOOTAGE ON ANDROS

February 22, 2017 by Rolling Harbour

SAWFISH: UNIQUE LIVE BIRTH FOOTAGE ON ANDROS

The word ‘awesome’ – a word of Biblical origin and medieval usage connoting an experience of wonderment with an element of dread* – lost its power once it became the common verbal currency for describing the offer of a beer, a photograph of a sulky cat, or a so-so pub band. Where to turn for something truly momentous? Oh, actually that might do nicely. Breathtaking, astounding, astonishing, awe-inspiring, staggering, extraordinary, stupendous, and spectacular are examples of synonyms that have retained at least some of their power. And perhaps ‘mind-blowing’, though it’s a bit substance-tinged. ‘Amazing’ has pretty much gone the way of awesome. Amazeballs and badass? Let’s not!

Ok. Having got that linguistic grump out of the way (index under ‘English Language, debasement of, modern usage in), here’s the real deal: a truly phenomenal short video of a smalltooth sawfish Pristis pectinata safely giving live birth in the wild to her 5 babies (which are called pups) on Andros during a FSU research trip. The pups emerge as small replicas of their parent, complete with their hedgetrimmer-style rostrums, ready to swim away. Fishes that carry their young and give birth to one or more developed juveniles in this way are called ovoviviparous.

The commentary is clear and informative, the research potential for this vulnerable species is considerable, and if you have a soul and a spare 3 minutes, you really should watch this!

This unique recorded event took place last December. The joint research trip to Andros by the FSU Coastal and Marine Lab and NOAA was led by Dr. Dean Grubbs. The purpose of the research was to discover evidence of any exchange between the sawfish population in the U.S. and Bahamas. You can find out more about the research and scientists at the FSUCML website. And if you want to get involved and take part in an expedition, click GET INTO THE FIELD

RELATED POSTS

RH SAWFISH PAGE – pics, facts and vids, including how the rostrum is used in feeding

GUITARFISH (WTF? 8)

* ‘Awful’ had the same meaning as awesome, historically – cf dreadful. It did not mean a bad film or a lousy restaurant.This recent photograph by Adam Rees of Scuba Works was taken in Florida waters. It is one of an astonishing school of 8 smalltooth sawfish, the largest group Adam has ever encountered.

Credits: Header, Grant Johnson @60poundbullet (Bimini), with many thanks; BNT / Buzz Cox (Grand Bahama); Adam Rees / Scuba Works

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.

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

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)

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)

PREHENSILE TALES FROM THE REEF (2): HIPPOCAMPI

October 25, 2016 by Rolling Harbour

PREHENSILE TALES FROM THE REEF (2): HIPPOCAMPI

It is a statistical fact that no one in the world – not even the meanest despot or cruellest tyrant – fails to love seahorses. It would be fair to add that in certain parts of the world, some people love them too much. In more than 65 countries. To the tune of an estimated 150 million a year that are used in the ‘traditional medicine’ trade. An attrition rate that is unsustainable in the long or even the medium term – with the bleak consequence that it won’t be long before people must look elsewhere for their source for Genital Tonic Pills.

Medicinal use – of empirically vague benefit to its enthusiasts – is joined by the aquarium trade in accounting for the removal of very large numbers of seahorses from their accustomed surroundings. At least these creatures live on (rather than being dried out alive), though research suggests that the survival rate of seahorses in captivity is low.

Do you sometimes hanker for a plastic brooch or paperweight with a tiny seahorse embalmed inside it? It would be good to resist the temptation to buy such things in seaside shops or online. Your little specimen will be one of a million or so souvenir seahorses sold each year, alongside seashells, starfish, sponges and (protected) corals.

As you contemplate your purchase, you may be reassured to find that the product is labelled ‘environmentally friendly’, ‘responsibly sourced’ or ‘from a sustainable source’. You can make up your own: ‘lovingly harvested from the bluest oceans’, maybe. In the words of the SEAHORSE TRUST:

“Nothing could be further from the truth; there is nothing sustainable about this exploitation of the seas. You can make change by not buying them. If there was no market there would be no trade.”

USES FOR SEAHORSES: MEDICINE OR (WITH SCORPIONS) STREET FOOD

SEAHORSES: PREHENSILE TALES FROM THE REEF

August 12, 2016 by Rolling Harbour

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s a year since I last posted about these amazing little creatures, seahorses. I featured a number of photos by Melinda Riger, a couple of videos, some useful facts about them, and for some reason some useless facts that I came across in researching the post. You can chase it down here: SEAHORSES 1

Adam Rees of SCUBA WORKS is another diver, like Melinda, who combines great underwater experience with wonderful photographic skills. This posts showcases some of Adam’s seahorse photography, and if it doesn’t want to make you explore the reefs, I can’t think what will…

Seahorse (Adam Rees / Scuba Works)

Seahorse Range Map Map: Seahorse range (Nat Geo)

Seahorse (Adam Rees / Scuba Works)

shlifecycle-e1313548153493

Seahorse (Adam Rees / Scuba Works)

Seahorse by Alex Konahin

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

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

July 7, 2016 by Rolling Harbour

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

Imagine that you are swimming along resplendent in your snorkelling 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…?’ 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) (© AMNH\D. 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, except final one ‘cralize wiki’; Hyperallergic for the historic image; Sia Big Fish for the video