Imagine that you are swimming along resplendent in your snorkeling gear (me) – or in scuba gear for the advanced swimmer (you). There, below you, camouflaged against the sea bottom is a fish. A strange-shaped brown sort of creature with odd side fins. As it progresses over the gravelly sand, your immediate reaction is ‘What the f…?’ Its fins seem to be turning into… wings. Like this:
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.
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
Here’s a short video of a flying gurnard on the move, from ‘Sia Big Fish’
Credits: All main images Adam Rees / Scuba Works with many thanks as ever, except final one ‘cralize wiki’; Hyperallergic for the historic image; Sia Big Fish for the video
FAIRY BASSLET (‘MIND YOUR GRAMMA’): BAHAMAS REEF FISH (33)
The Fairy Basslet is a tiny brightly-coloured fish with a pretentious alternative name. It is otherwise known as the Royal Gramma (Gramma loreto). These fish are found in the coral reefs of the (sub)tropical western Atlantic. They are also found in aquariums anywhere you like, being small, bright, placid and generally good-natured.
Conveniently, the basslet is unlikely to be confused with any other species. Its striking two-tone colour scheme of purple and yellow is hard to miss. The purple front half (which is presumably where the ‘royal’ comes from, being a regal or imperial colour) may also be violet or even blue in some fish and / or in some light conditions. Another identification pointer is a black spot on the dorsal fin.
You’ll notice that the basslet above appears to be upside down. Which is because it is – this isn’t an inadvertent photo-flip. These little fish tend to orientate themselves to be parallel with the closest surface. This leads to them happily swimming upside down, or aligning vertically. As one article I read says severely, “this behaviour is not to be mistaken for illness”.
Fairy basslets / royal grammas are also CLEANER FISH. They pick parasites and dead skin off larger fish that visit so-called cleaning stations to be attended to by tiny fish and cleaner shrimps. The basslets also their customer’s gills and even their teeth. The deal is that, in return, the large fish do not eat the cleaners, even the snack-sized ones rootling around inside their mouths.
MUTUALISM
The relationship is a good example of mutualism, a type of symbiotic relationship where both species involved benefit from their interactions. Think also of cattle egrets and cows.
WHAT ABOUT BREEDING?
I really can’t improve on this rather touching description from Wiki:
“The male will build the nest among rocks using pieces of algae.The male will then lead the female to the nest, where she will deposit 20-100 eggs in the nest. During the breeding period, this behaviour is repeated almost every day for a month or longer. The eggs are equipped with small protuberances over the surface with tiny threads extending from them which hold onto the algae of the nest and keep the eggs in place. The eggs will hatch in five to seven days, normally in the evening…”
HOW COME THE NAME ‘GRAMMA LORETO’?
This official name became a brainworm with me after I started this post. I had to check it out. The ‘Gramma’ part simply denotes a member of the genus of fishes in the family Grammatidae.
The Loreto part is more mysterious. It is an an ancient town in Italy; and the name of several British schools, including – almost too good to be true – a school called Loreto Grammar. But it was also the name of Señorita Loreto Martínez, who caught the ‘type specimen’ while fishing in the bay at Matanzas, Cuba.
MISC
I failed to be able to resist finding out whether any country of the world has a purple and yellow flag. The answer is, no. However I am delighted to be able to report that the flag of the Independent Party of Uruguay is basslet-coloured.
Credits: all fantastic photos by Melinda Riger of Grand Bahama Scuba; magpie pickings of an unacademic sort for facts and speculation
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
Pederson’s Shrimps Ancylomenes pedersoni(also known locally as Peterson’s shrimps), are one of several species of cleaner shrimp found in The Bahamas, and more generally in the Caribbean seas. The species was named in 1958 by a multifaceted medico-oceanologist-zoologist Fenner A. Chace. He seems to have specialised in shrimps, finding distinct and differing species and naming them (not unreasonably) after himself (chacei); or colleagues and people he knew / admired; and in one case his wife. Mr Pederson was among the lucky ones.
This tiny transparent creature with its vivid blue / purple markings and straggling pale antennae is unmistakeable, and helpfully cannot be confused with any other locally found shrimp species. Here’s an idea of its size, compared with a human finger and a blue parrotfish (on its flank).
WHERE DO THESE SHRIMPS LIVE?
Their preferred home is… and it’s certainly a left field choice among sea creatures… in amongst the stinging tentacles of certain sea anemones. Not only do they not get stung, but of course they are well-protected by the defensive pain that their hosts can inflict. They are usually found singly or in pairs, but sometimes a whole colony may inhabit the same anemone.
SO EXPLAIN HOW THEY DON’T GET STUNG
Ok. The shrimps gradually build up a kind of resistance by pressing their bodies and antennae against the tentacles of the host anemone for increasing lengths of time, until they become immune. It’s like one of those kids’ electric buzzer / rheostat machines. Or a TENS machine (for those who know about backache).
IS THERE A DOWNSIDE TO ALL THIS?
Yes indeed. If a shrimp moves away from its host for a few days, it has to start the process of immunisation all over again. So presumably they tend to stay home-lovin’.
Home sweet home for the Pederson shrimps
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…
YELLOWTAIL (REDFIN) PARROTFISH: BAHAMAS REEF FISH (54)
The yellowtail parrotfish (sometimes known as a redfin) is one of around half-a-dozen kinds of parrotfish found among the coral reefs of the Bahamas, and sometimes in seagrass areas. There are many other related species worldwide (about 80). Parrotfish are among the most important fishes on the reef because they play a major role inBIOEROSION , a vital process for the health of the reef.
A. FEEDING & BEACH BUILDING
Their dental arrangements – a mouthful of meshing teeth – form the characteristic ‘beak’
Primarily herbivores but also snack on small creatures, organisms, or even molluscs
As they feed on their favourite algae, their teeth grind up the coral which they ingest
They digest the coral & excrete it as sand, becoming a component of your favourite beach
The teeth grow continuously, replacing ones worn away by grinding coral as they graze
They are a vital species in preventing algae from choking coral: essential reef cleaners
B. PARROTFISH: PERSONAL INFORMATION
Some secrete a protective mucous cocoon to sleep in or as concealment from predators
Mucous also helps to heal damage, repel parasites, & protect them from UV light
As they develop from the juvenile stage, most species change colour significantly
In some species, juveniles change colour temporarily for protective purposes
These are “sequential hermaphrodites”, turning from female to male (‘protogyny’)
Single males tend to have several lady friends, and aggressively defend their love rights
Parrotfish arePELAGIC SPAWNERS. Females release many tiny buoyant eggs into the water
The eggs float freely then eventually sink to the coral until they hatch
Unlike almost all other fishes, they use their pectoral fins to propel themselves
Feeding behaviour / dietary requirements make them (thankfully) unsuitable for aquariums (or aquaria, if you prefer)
WHAT WAS THAT ABOUT CHANGING SEX?
Parrotfish may undergo sex reversal in which developing female fish become males
Parrotfish born male remain male throughout their lives (“primary males”)
Female-born fish may change sex & colour to become male (“secondary males”)
Secondary males are fertile and generally mate with a single female
Females that stay female live in harems protected by a dominant “supermale” BUT…
…if the supermale dies, the largest female in the group changes sex to become male…
…AND amazingly adopts the coloration of the supermale (best ‘astounding fact’ of all)
ARE PARROTFISH EDIBLE? JUST ASKING…
Parrotfish skin is very tough but their flesh is soft and degenerates quickly
Some species (eg blue parrotfish) carry ciguatera toxins – to be avoided
They are not considered a fishing target in Bahamas, nor a food-fish
Parrotfish are eaten elsewhere in the world however, for example Jamaica (cooked)
In Hawaii they are eaten raw – at one time they were reserved for royalty
Credits: Melinda Rogers / Dive Abaco for her great illustrative images. All photographs were taken on the reefs of Abaco; Florida Museum to cross-check facts; VIDEO – Angari Foundation
The creole wrasse Clepticus parrae is a small wrasse species, with adult males reaching about 12 inches long. During its life, the fish will change colour significantly. A juvenile is almost completely violet-purple. As it matures, it becomes paler and develops patches of yellow on the rear part of its body.
Creole wrasse are found throughout the tropical and subtropical waters of the western Atlantic, from Florida south to Brazil. The habitat includes Bermuda, the Caribbean Sea, and the Gulf of Mexico. Their conservation status is LCLeast Concern.
These are social fish that live in groups around coral reefs. They are usually found in shallow water, but – perhaps surprisingly for such small creatures – they have also been found as deep as 100m.
The groups of wrasse feed on plankton, small jellyfish, pelagicTUNICATES, and invertebrate larvae. They are active in groups by day, but at night they separate and each fish finds its own safe crevice in the reef to sleep.
ANYTHING ELSE WE NEED TO KNOW?
Yes indeed. Their intriguing breeding regime – how unlike our own dear species. The creole wrasse is aprotogynous hermaphrodite. The largest fish in a group is a dominant breeding male, while smaller fish remain female. If the dominant male dies, the largest female changes sex. Mature males congregate atleksto breed, at which they display and are approached by females before mating with them. These leks are reminiscent of certain clubs and bars in the less reputable parts of some towns and cities. Or so I am told.
It’s been a while since I included a Rolling Harbour musical diversion. However, the colour of this small fish nudged my memory back to 1968 and DP’s debut album (line-up Mk 1 of several hundred, or so it seems now). Hence the post title. Anyone who remembers this ‘wasn’t there’. Anyone who doesn’t remember it obviously wasn’t there either…
FUN FACT: an early appraisal of the Purp’s music includes the description “a slow and pompous din, somewhere between bad Tchaikovsky and a B-52 taking off on a bombing run”
I don’t think this guy thinks much of that. And quite right too
All wrasse photos from Melinda’s archive; DP cover borrowed from Am@z@n; MP3 moi
The ‘WTF?’ series started with relatively conventional species eg REMORAS and became progressively more bizarre. In due course, having covered the excellently strange BATFISH it was time to ramp up the stakes: with many thanks to scuba expert Adam Rees for use permission for his terrific photos, I present… the FROGFISH.
The frogfish is a kind of anglerfish found in almost all tropical and subtropical oceans and seas. There are about 50 different species worldwide, covering an astonishing range of strange appearances. They generally live on the sea floor around coral or rock reefs. In size they vary from tiny to about 15 inches long – although ‘long’ is a flexible concept because they are to an extent shape-changers in height and width.
FROGFISH SUPERPOWERS YOU MAY WISH TO HAVE
INVISIBILITY CLOAK . Frogfish are masters of disguise and camouflage. This enables them to catch their prey with minimal effort and also to avoid predators. Their camouflage methods – broadly known as ‘aggressive mimicry’ – include
Ability to change colour for days or even weeks to mimic their surroundings
Getting covered in algae and other organic matter that matches their habitat or
Looking inherently like a plump rock or in some cases, plant
Fear for the life of the spider crab…
IRRESISTIBLE ATTRACTION
A sort of frontal dorsal fin called an illicium to which is attached a
Lure called an esca which may mimic a worm, shrimp or small fish etc and which is
Retractable in many species and
Regenerates if it gets mislaid
The ‘dollop of cream’ thing is the esca. Note the characteristic large mouth
BUOYANCY CONTROL & SHAPE-SHIFTING
Most frogfish have a ‘gas bladder’ to control their buoyancy.
Some species can change shape or even inflate themselves by sucking in quantities of water in a so-called defensive ‘threat display’.
HOW DO FROGFISH REPRODUCE?
Although not conventionally attractive creatures, frogfish clearly manage to reproduce. Little is known about the techniques in the wild, but one is probably ‘with care’, especially for a male frogfish who may not survive for long if he hangs around after fertilisation has taken place. It has been noted that females tend to select far smaller males to fertilise their huge numbers of eggs, perhaps for that very reason.
Spot the esca…
FROGFISH FEEDING SKILLS – GOOD OR BAD?
When deploying the lure, potential prey that comes too close to that wide mouth stands no chance. A frogfish will strike in a fraction of a second. Frogfishes have voracious appetites for crustaceans, other fish, and even each other. I can do no better than borrow this vivid description of a feeding frogfish:
“When potential prey is first spotted, the frogfish follows it with its eyes. Then, when it approaches within roughly seven body-lengths, the frogfish begins to move its illicium in such a way that the esca mimics the motions of the animal it resembles. As the prey approaches, the frogfish slowly moves to prepare for its attack; sometimes this involves approaching the prey or “stalking” while sometimes it is simply adjusting its mouth angle. The catch itself is made by the sudden opening of the jaws, which enlarges the volume of the mouth cavity up to twelve-fold, pulling the prey into the mouth along with water. The attack can be as fast as 6 milliseconds. The water flows out through the gills, while the prey is swallowed and the oesophagus closed with a special muscle to keep the victim from escaping. In addition to expanding their mouths, frogfish can also expand their stomachs to swallow animals up to twice their size.“
HOW DO FROGFISHES GET AROUND? SWIM? WALK? CRAWL?
Frogfishes do not in fact move around a great deal. Using their camo advantages, they prefer to lie on the sea floor and wait for prey to come to them. As mentioned in the quote above, they may slowly approach prey using their pectoral and pelvic fins to “walk” along the sea bottom. They can swim using their tail fin (or in some species by simple ‘jet propulsion’ by forcing water out of their gills) but rarely do so – they don’t feed on the move, and they are adapted to the sea floor environment where they food is readily available. However their “walking” ability is limited to short distances.
DO FROGFISH HAVE OTHER COLOUR SCHEMES?
Indeed they do. In stark contrast to the camo species, some frogfishes are hi-lighter bright. Here are two of my favourite photos by Adam that show this clearly. I’ve no idea if these are a male and female. I suspect they are different species. I think the brown one is a striated frogfish and the other is… a yellow frogfish. Some people keep these creatures in aquaria, but apparently it is impossible to sex them, and they have to be kept on their own for everyone’s peace of mind…
FROGFISH INFOGRAPHICS
FROGFISH VIDEOS
These two videos, from Lester Knutsen and Daan Van Wijk respectively, show some of the characteristics I have written about above. Both are short and both are fascinating.
Credits: All main photos, Adam Rees of Scuba Works with many thanks; wiki for ‘spot the esca’, red quote & basic info; videos Lester Knutsen & Daan Van Wijk; Jens Petersen /wiki; Teresa Zubi for website & gifs; infographics, authors u/k
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.
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)
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.
** 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)
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 ofBLENNY. 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.
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…
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…
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)
“Deck the Reefs with Worms Like Christmas Trees… Fal-La-La-etc-etc ” is a traditional Carol familiar to all. Well, most. Ok, some, then. Oh right – maybe with different words? Anyway, now is the perfect time to take a look at these remarkable subsurface symbols of seasonal good cheer (nb they are wonderful animals not gorgeous plants).
10 CHRISTMAS TREE WORM FACTS TO PONDER
The 2 colourful spirals are not the worm, but complex structures for feeding & respiration
The spirals act as specialised mouth extensions for ‘filter-feeding’
Prey is trapped by the feathery tentacles & guided by cilia (microscopic hairs) to the mouth
The tentacle things are radioles and act as gills for breathing as well as prey traps
There is little evidence that prey slide down the spiral to their doom, like on a helter-skelter
The actual worm lives in a sort of segmented tube, with extremely limited mobility skills
It contains digestive, circulatory & nervous systems – and a brain in the middle of it all
The worm also has a tiny drainage tube (I think I have this right) for excretion etc
They embed themselves into heads of coral such as brain coral. And stay there
And yes, the Christmas trees are retractable… (see below for some action)
HOW DO THE WORMS… YOU KNOW… ERM… REPRODUCE?
This is a delicate area. They are very discreet, but as far as I can make out they eject gametes from their what-I-said-above. There are mummy and daddy worms, and their respective gametes (eggs and spermatozoa) drift in the current and into each other to complete the union. The fertilised eggs develop into larvae, which settle onto coral and burrow into it as their parents did, build their protective tubes, and the process begins again.
YOU DON’T REALLY UNDERSTAND THESE CREATURES, DO YOU?
I won’t lie. I found it hard to work out how the CTWs function in practice. There are plenty of resources showing them in their full glory, but that only takes one so far. Then I came across a short video that shows it all brilliantly simply (except for the reproduction part).
The worms, in their coral burrows, hoist their pairs of ‘trees’. You can easily see small particles – zooplankton – drifting in the water, and the radioles swaying to catch potential food. Suddenly it all makes sense (except the repro bit – I haven’t found footage of that). Next: the New Year Worm (there is no Easter worm).
A WHOLE FESTIVAL OF CHRISTMAS TREE WORMS
Credits: Melinda Riger (Grand Bahama Scuba); Nick Hobgood; Betty Wills; Video by ‘Super Sea Monkey’; Reef Collage by RH; MarineBio; Wikibits & Magpie Pickings
HappyChristmas toallthosewho putupwithRHwithsuchfortitude over many years
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 poorSteve 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…
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
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
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:
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.
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
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
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…
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
There’s no doubt about it, barracudas have a particularly unwelcoming look to them. They exude menace. There’s something about the torpedo shape, the primitive head, and the uncomfortably snaggle-toothed grin-with-underbite that suggests a creature not to be underestimated.
And that smiley mouth – rather scornful and derisive, is it not? A powerful creature in its element, where you are the intruder… and it sees it like that too. An adult barracuda may grow to nearly 6 foot long. Your are only temporarily of its world, and (it observes) you are keeping your distance.
The dental arrangements of a ‘cuda are a wonder in themselves. The teeth are razor sharp; an orthodontist’s nightmare because they are all different sizes and grow at different angles. Some are conventionally set in the jaws, but some actually grow from the roof of the mouth. There are ‘normal’ sized teeth interspersed with wicked-looking fangs that randomly grow facing forwards, backwards and sideways.
WHY THE UNTIDY MOUTH FURNITURE?
The name Barracuda is thought to derive from the Spanish word barraco meaning (in one of its senses) “overlapping teeth”. The jaws that contain the teeth are strong, and the underbite adds to the effectiveness of ‘cuda predation. Prey is highly unlikely to escape once caught. When the jaws snap shut, the sharp angled teeth – particularly the back-facing ones (cf fishhook barbs) prevent the victim from pulling away. Then the munching and shredding can begin inside what is essentially a perfectly equipped multi-bladed mincing machine.
I featured the extraordinary, colour-transforming PEACOCK FLOUNDER Bothus lunatus a while back as part of a Bahamas Reef Fish series. These really are remarkable creatures, and I have decided to return to them mainly because of the wonderful illustrative photos I was able to incorporate. There are plenty of flounder facts too, but if you just enjoy the pictures and skip the blurb I’ll understand.
ROVING EYES
In the fish shown here, you’ll see that – surprisingly – both eyes are on the upper-side of the fish, above the rather grumpy mouth, whereas the head is horizontal to the ocean floor. Oddest of all, juveniles are constructed conventionally with bilateral eyes, and look like ‘normal’ fish rather than flatfish.
As the fish matures, in some magic way the mechanics of which I can only guess at**, the right eye grows round to the topside and the flounder transforms from a ‘vertical’ fish to a flatfish. For this reason, the PF is known as a ‘left-eye’ flounder. Maybe in other flounder species in the world – the southern hemisphere maybe? – the eye that moves round to the upper-side is the left eye.
The eyes of this fish have another special trick up their sleeves (so to speak). They operate completely independently. Thus the creature can look left and right, or forwards and backwards, simultaneously. It’s an excellent system for detecting predators coming from any angle. It’s a superpower we might all benefit from.
DO THEY HAVE ANY OTHER TRICKS WE SHOULD KNOW ABOUT?
Yes they do indeed. If you have been admiring the fish shown so far, you’ll have noticed that the colour of each one differs from the others. In addition to the predator-protection that the eyes provide, the peacock flounder can make itself (near) invisible. They can rapidly change colour to match their surroundings. There are 3 reasons for this: to avoid / confuse predators; to conceal themselves on the sea-floor to catch passing prey; and, as dive expert Fred Riger has pointed out, “the male peacock flounder can, and does greatly intensify his colours to declare territory and attract females. When doing this the males will also signal with the left pectoral fin, sticking it straight up and waving it around.”
The same fish, photographed over several minutes as it moves over the ocean floor
Matching the background happens as the fish swims, and in a few seconds. When they rest on the sea-floor, the camouflage may even become total. In #4 above you can just about make out the eyes. The whole effect is known as ‘cryptic coloration’ or CRYPSIS. In contrast, the image below shows just how adaptable the transformation can be. Note how the fish can even mimic the pinkish tinge of the sand perfectly. If threatened, the fish will bury itself in the sand, with just its eyes showing.
HOW DO THEY MANAGE TO CHANGE COLOUR IN SECONDS?
It’s complicated! A simple answer is: a mix of hormones, pigment-cells and vision, all coordinating rapidly. The colour change works in two ways: pigments are selectively released to the skin cells; and other pigments can be selectively suppressed. An analogy might be image manipulation using variations in brightness, saturation etc. Not convinced? Then watch this short video and prepare to be impressed. Astonished, even.
WHAT IF A FLOUNDER CAN’T SEE CLEARLY FOR SOME REASON?
As with many (all?) superpowers, there is usually some kryptonite-style flaw. A flounder with a damaged eye, or one temporarily covered (by sand, for example) will have difficulty in changing colour – possibly at all, or at any rate with the swiftness it needs to have.
THESE SIDEWAYS FISH – HOW DO THEY… YOU KNOW…?
Take a look at the fish above with its top fin raised. It’s a ‘ready’ signal in a harem. Male flounders have a defined and defended territory within which live up to 6 females – a so-called ‘harem.’ I can do no better than borrow the description of the rituals from an article derived from scientific papers byKonstantinou, 1994; Miller, et al., 1991in the websiteanimaldiversity.org/…ounts/Bothus_lunatusTo which I can only add, ’15 seconds, eh?’
“Mating activities usually begin just before dusk. At this time, a male and a female approach each other with the ocular pectoral fin erect. The two fish arch their backs and touch snouts. After this interaction the female swims away, and the male sometimes follows, approaching the female again from the left side. At this point the male pectoral fin is erect and the female pectoral fin moves up and down, possibly signalling willingness to mate. The male then positions himself underneath the female and mating begins. This process consists of a mating rise, during which the female and male rise in the water column together. On average, these rises last about 15 seconds. At the highest point of this rise, usually around 2 m above the substrate, gametes from both fish are simultaneously released, producing a cloud of sperm and eggs. Once the couple returns from the rise, the male “checks” to make sure mating was successful, and the pair separates quickly, swimming away from each other in opposite directions. Not all mating rises are successful, and the process of “checking” is thus important. The exact purpose of the mating rise in these flounders unknown; possible reasons for rising include better dispersal of gametes and predator avoidance.”
Peacock Flounder – Kim Rody Art
**This may in fact have been through sheer laziness
Credits: Melinda Riger & Virginia Cooper / Grand Bahama Scuba; Melinda Rogers / Dive Abaco; Adam Rees / Scuba Works; Kim Rody; animaldiversity.org; magpie pickings and other credits in the text
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.
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 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)
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
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.
** 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)
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
ROLLING HARBOUR ABACO 
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