COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS

January 19, 2022 by Rolling Harbour

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

The Cookiecutter shark Isistius brasiliensis (aka the less scary, more genial sounding ‘cigar shark’), might be an ideal candidate for a Room 101 nemesis.** These little beasts – a species of dogfish shark – are found in several mainly island-based areas dotted around the globe, including in Bahamas waters.

HOW COME THE NAME?

These sharky little b@st@rds (*scientific term*) attack marine mammals and fishes, attaching themselves by suction and gouging out perfect round plugs of skin and flesh, leaving what are sometimes called ‘crater wounds’. Then they eat them. Imagine getting hold of a really sharp domestic cookie cutter with circular rows of razor-sharp teeth, and grinding it hard into your thigh. There! That!

The size of an adult shark:16″ max

The term ‘cookiecutter’ is also a pejorative slang term, meaning mass-produced, lacking in originality, or boringly samey, as in cookiecutter cars or TV genres etc. The little critters under consideration here are anything but…

HORRIFYING COOKIECUTTER FACTS

Live in the depths, rise vertically in the day & dive back down at dusk
Undersides have light-emitting ‘photophores’ which emphasise…
…the dark collar which acts as a lure, resembling a small innocent fish
Bioluminescence lures prey & confuses predators (more on this below)
The glow is so strong it may last for some time after removal from water

Their lips are ‘suctorial’ = they attach tightly to their target
The jaws then gouge out the victim’s flesh in a remarkably neat circle
Omni-vicious: any medium to large ocean creature is vulnerable to attack
There are even occasional reports of humans being targeted

Here are two Blainville’s beaked whales that I photographed from the BMMRO research vessel. The top whale has a number of circular healed attack marks and a recent one. You can see how deep the gouged hole is. The other has well-healed scars.

Multi-toothed: top rows of small teeth, rows of larger teeth on the bottom
The lower teeth are the cutters, acting like a saw when locked on
See header image and below for full details

HOW EXACTLY DO THEY DO WHAT THEY DO?

I can explain it no better than the renowned authority Prof. W. K. P. Dear: “the suctorial lips ensure a tight seal. It then bites, using its narrow upper teeth as anchors while its razor sharp lower teeth slices into the prey. Finally, the shark twists and rotates its body to complete a circular cut, quite possibly aided by the initial forward momentum and subsequent struggles of its prey. The action of the lower teeth may also be assisted by back-and-forth vibrations of the jaw, a mechanism akin to that of an electric carving knife”.

ARE THESE SHARKS ‘PARASITES’, WOULD YOU SAY?

The behaviour of these sharks is an example of a symbiotic relationship between two species that is parasitic. This means essentially that one gains and the other suffers (eg humans & no-see-ums). This is distinct from commensalistic symbiosis, where one species gains and the other is unaffected (e.g. cattle egrets with cattle); and mutualistic symbiosis, where both gain (e.g. cleaner fish & groupers). So, in a word, yes.

An ‘ambush predator’: these little sharks ‘hover’ in the water column waiting…
They are capable of rapid movement to catch up & latch onto prey
They will eat a passing small fish, crustacean or even squid as a snack
Sometimes they operate in schools; there is safety in numbers
The schools are thought to increase the ‘lure’ effect of the dark collar

A beached whale that’s been heavily targeted

FUN FACT TO COUNTERACT THE BAD STUFF

In the late c20, more than 30 U.S. Navy submarines were forced back to base to repair damage caused by cookiecutter shark bites, either to the neoprene footings of sonar domes or to rubber-sheathed cables. The problems were solved by using fibreglass. Oceanographic equipment and telecommunications cables are also recorded as being damaged by these sharks.

Cookiecutter Shark – the real deal

MONSTERS OF THE DEEP

These great cards from the weirdly spelled WIERD ‘N’ WILD CREATURES provide excellent factual info. Their CCS card is no exception. You’ll find more details here about the effect of the bioluminescence and so on, written as clearly as I might hope to.

** “The worst thing in the world varies from individual to individual. It may be burial alive or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.” (George Orwell, 1984). Being in a tank with some cookiecutters might count.

Alright now… the wounds eventually heal

Credits: BMMRO – header image; beaked whale photos – Keith Salvesen / BMMRO; Te Ara NZ for the main jaw image; all small images with thanks to Wiki and respective photographers who took the time to upload them for all to enjoy & learn from; ‘wierdnwonderful creatures’ for the monster card; range map from Wiki

WTF? (WHAT’S THAT FISH?): THE FROGFISH

October 18, 2019 by Rolling Harbour

The Astoundingly 5* Strange Frogfish (Adam Rees / Scuba Works)

WTF? (WHAT’S THAT FISH?)

A COMPENDIUM OF SUBSURFACE WEIRDNESS

A SERIES OF 15 OF THE STRANGEST SEA CREATURES IN BAHAMAS WATERS

INTRODUCTION

WTF? stands for ‘What’s That Fish’? But it might also be your exclamation when you come across one of these creatures. The WTF? series highlights some of the unusual, curious, weird and downright extraordinary fishes that inhabit the waters of the northern Bahamas. Some represent local forms of a species found elsewhere in the world; others are in their own evolutionary cul-de-sac. Just as I think I have seen it all, so another oddity crops up somewhere that demands inclusion.

The WTF? series, put together over several years, is intended to be the most direct route to an underwater menagerie of piscine strangeness, with some great photos to whet your appetite to learn more about these fascinating denizens of the ocean.

1. THE FROGFISH

* CLICK ON THIS TITLE TO BE TRANSPORTED TO THE STRANGE WORLD OF THE FROGFISH *

Frogfish (Adam Rees, Scuba Works) Credits are given in the individual articles. Thanks to all those that have provide the photos, without which this type of illustrated, unscientifically scientific poke around in the ocean depths would not be possible.

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

September 13, 2018 by Rolling Harbour

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

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

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

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

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

DO THEY HAVE ANY OTHER TRICKS TO WATCH OUT FOR?

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

Concealed against coral

HOW DO THEY FEED?

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

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

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

ANYTHING ELSE WE NEED TO KNOW?

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

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

COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS

February 5, 2018 by Rolling Harbour

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

HOW COME THE NAME?

These sharky little b@st@rds (*technical term*) attack marine mammals and fishes, gouging out perfect round plugs of skin and flesh, leaving what are sometimes called ‘crater wounds’. Then they eat them. Imagine getting hold of a really sharp domestic cookie cutter with circular rows of razor-sharp teeth, and grinding it hard into your thigh. There! That!

The size of an adult shark:16″ max

HORRIFYING COOKIECUTTER FACTS

Live in the depths, rise vertically in the day & dive back down at dusk
Undersides have light-emitting ‘photophores’ which emphasise…
…the dark collar which acts as a lure, resembling a small innocent fish
Bioluminescence lures prey & confuses predators (more on this below)
The glow is so strong it may last for some time after removal from water

Their lips are ‘suctorial’ = they attach tightly to their target
The jaws then gouge out the victim’s flesh in a remarkably neat circle
Omni-vicious: any medium to large ocean creature is vulnerable to attack
There are even occasional reports of humans being targeted

Multi-toothed: top rows of small teeth, rows of larger teeth on the bottom
The lower teeth are the cutters, acting like a saw when locked on
See header image and below for full details

HOW EXACTLY DO THEY DO WHAT THEY DO?

ARE THESE SHARKS ‘PARASITES’, WOULD YOU SAY?

The behaviour of these sharks is an example of a symbiotic relationship between two species that is parasitic. This means essentially that one gains and the other suffers (e.g. no-see-ums!). This is distinct from commensalistic symbiosis, where one species gains and the other is unaffected (e.g. cattle egrets with cattle); and mutualistic symbiosis, where both gain (e.g. cleaner fish & groupers). So, in a word, yes.

An ‘ambush predator’: they ‘hover’ in the water column waiting…
They are capable of rapid movement to catch up & latch onto prey
They will eat a passing small fish, crustacean or even squid as a snack
Sometimes they operate in schools; there is safety in numbers
The schools are thought to increase the ‘lure’ effect of the dark collar

A beached whale that’s been heavily targeted

FUN FACT TO COUNTERACT THE BAD STUFF

Cookiecutter Shark – the real deal

MONSTERS OF THE DEEP

Alright now…

PS Apologies to anyone who bothered to wade through this, and stayed awake long enough to notice that formatting gremlins struck halfway through

WTF? (WHAT’S THAT FISH?) 11: STARGAZER FISH

September 6, 2016 by Rolling Harbour

WTF? (WHAT’S THAT FISH?) 11: STARGAZER FISH

It’s a real shocker! This fish is a serious contender. An A-list horror-fish. The WTF? series has featured some extraordinary, bizarre and frankly unbelievable fish species. Here’s one that might just blow them all out of the water. So to speak. Not only is this fish weird in a number of respects, but it is also dangerous. Behind its eyes it has a special ‘electric organ’ (a “Hammond”?**) that produces a shock when touched. Oh for a superpower like that, even if only to be used defensively.

“They’re the meanest things in creation,” fish scientist William Leo Smith, who owns a stargazer, told the New York Times. “I was so excited to get it. It’s the worst pet on earth.”

‘Fish out of water’. Note (but do not touch) the area behind its eyes… Northern_Stargazer (Canvasman21 wiki)

The Northern Stargazer Astroscopus guttatus whiles away the long lazy days lying mostly buried by sand, the stargazy eyes on top of its head picking out prey – mostly small fish – to ambush and stuff into its bizarre YKK zip-mouth. It can bury itself in seconds. An adult stargazer may grow to nearly 2-foot of concealed eating machine. They will stay put unless disturbed, confident that a false move by a creature – it could be you in your flippers – will mean it will be in for a shock.

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10 STARGAZER ATTRIBUTES TO ADMIRE (BESIDES THE ELECTRIC SHOCKS)

The strange mouth looks as it does because it is fringed to keep out sand
The head-top eyes can be made to protrude to allow a wider field of vision
It ambushes small fish and swallows them whole (see video below)
To lure prey, stargazers discharge seawater through their gills… (Reader: why?)
It causes the sand to move about – possible lunch is waiting for a fish further up the food chain
They are born with eyes on side of the head; they move to the top as they grow from the larval stage
They are content to be solitary, except in the Spring (for the usual reasons)
Apparently “little is known about the mating behaviours of these creatures”. A pity, I feel.
They have no scales, but they make up for that with an impressive 13 anal spines
Unimpressed? Well they also have venomous spines near their gills & above their pectoral fins

stargazer-fish.jpg.653x0_q80_crop-smart

WEIRD FISH – AND WHAT’S WITH THE WEIRD NAME?

I wondered that too. The Astroscopus part derives from the Greek, ‘astro’ (star) and Latin ‘scopus’, a conceptual noun combining watching and targeting – think ‘telescope’, or ‘far-target-watching’. The guttatus (L) part simply means spotted or speckled. A Homo guttatus may need mild medical attention.

Stargazer clip (Wideangl)

THOSE ELECTRIC SHOCKS – HOW BAD ARE THEY?

Well. I kinda knew you’d ask so I looked into it. According to the exceptionally cool ‘Monsters of the Deep’ (see credits), the stargazer shock is approximately 50 volts. The British Health and Safety Executive, whose job is normally to interfere with almost every aspect of daily life in the UK (“you are strongly advised not to drink from bottles marked ‘Rat Poison’ portraying a Skull & Crossbones motif, lest disappointment should result”) has assisted:

A voltage as low as 50 volts applied between two parts of the human body causes a current to flow that can block the electrical signals between the brain and the muscles. This may have a number of effects including: stopping the heart beating properly; preventing the person from breathing; causing muscle spasms.

The exact effect is dependent upon a large number of things including the size of the voltage, which parts of the body are involved, how damp the person is, and the length of time the current flows.

Sadly, you are quite unlikely to find a stargazer in Abaco waters, which lie slightly beyond their fairly limited western Atlantic range. But hop over to Floridian waters, move a bit north, and you might meet one.

**A musical instrument allusion

Credits: Adam Rees / Scuba Works; Canvasmas21 wiki; Nat Geo Kids; MONSTERS OF THE DEEP (cool underwater site to check out!); Casey Patton / FMNH; Mother Nature Network (inc for video); Wideangl (clip)

“ALIEN FROM THE DEEP”: ABACO’S SCALELESS BLACK DRAGONFISH

October 13, 2014 by Rolling Harbour

“ALIEN FROM THE DEEP”: ABACO’S SCALELESS BLACK DRAGONFISH

Prepared to be terrified. Beneath the placid turquoise waters of Abaco lurks a ruthless and implacable killer of hideous mien, armed with vicious teeth … Yes, as the music from Jaws begins to throb round your temples I bring you… THE SCALELESS BLACK DRAGONFISH, aka the Deep Sea Dragonfish or Viperfish (of which it is one type). Oh, and it’s about 8 inches/ 20 cms long.

The specimen shown here was found off Rocky Point, Abaco during a whale and dolphin research trip by the BMMRO. This is an area where typical low waters give way to the far deeper waters of an arm of the Great Bahama Canyon. It is an excellent place for whale watching, since one effect of the canyon is to provide plentiful food of the sort that cetaceans thrive on. The chances of you ever meeting a dragonfish are very slim indeed, since they live at depths up to 1500 metres.

~~MAP to be added after posting, to avoid FB’s deranged random ‘feature photo’ selection~~ The black star at the south end of Abaco (in the yellowish box) is where Rocky Point and Sandy Point are to be found.

Here is an account by BMMRO intern Luanettee Colebrooke who was lucky enough to be on the research vessel when this strange, vicious-looking creature was found. I have edited the material for present purposes, but I recommend reading the whole article which can be found on the BMMRO website HERE. You will get an excellent overview of a day’s research under the hot sun, and plenty about the collection of whale poop (a topic I have previously dwelt on HERE (“Familiar Feces“).

CREATURE by Luanettee’ Colebrooke, BMMRO intern, summer 2014

The crossing of this organism was by complete accident. It was something that none of us would have imagined finding floating along the surface of the water. For Dr Claridge, Jurique (another BMMRO summer intern from Cat Island) and I as Bahamians, who knew this creature even existed in our majestic waters? Who knew our waters were even that deep to hide this specimen? (I think Dr Claridge knew)

Our morning began as per the usual routine for a boat day. There are several research sites that we venture to regularly: Rocky Point for the coastal Bottlenose Dolphins, and an area about 2 miles south of Rocky Point for our very elusive and wary Blainville’s beaked whales, and the deep blue (a massive drop into waters that are 1500 metres deep) to listen for Sperm Whales.It is not that I do not believe that we have deep waters. The Tongue of the Ocean runs through the northern part of our country. My thought comes more from, ‘our waters are that deep’? To a point where light does not hit the bottom and organisms have to rely mainly on bioluminescence? It is a similar thought process I had when I saw a sperm whale for the first time. They are not small creatures of the sea. It is both an awe and scary thought that there are creatures out there we, as Bahamians, do not know exist in our waters.

Scaleless Black Dragonfish - BMMRO Abaco

“Our final activity of the day was tracking a sperm whale acoustically using a hydrophone…” There follows a graphic account of the technicalities of sperm whale poop collection and co-intern Jack’s “Faecal Dispersion Technique”. Then this: Jack stood up, Pringle in mouth and pointed to a black leather looking strap off of the port bow. “What is it?” Moving closer to the port, Jurique and I had our own thoughts. “It looks like a boxing glove strap,” he suggested. “More like an expensive underwater watch,” I mentioned. Dr. Claridge said, “It looks like a squid tentacle.” Jack added in, “More like the strap from a fin to me.” Our heads were turning with no closer answer. Taking it upon himself as the official sample collector, Jack popped back into the water to collect it. There were no sample pots large enough for it, so he had to use a large Ziplock bag to pick it up.

Letting out a surprised chorus when he got back on the boat, we wondered what the heck it was. It had a mouth and a weird white patch that at first, I thought was its eye. The ventral abdominal section seemed swollen as if it had expanded from the decreasing pressure rising from the sea. As we looked at it and took photos, we determined several characteristics of the deceased specimen without having to autopsy it. The first was that it had three rows of needle like teeth that turned inward. There was what we assumed to be an angler under its ‘chin’ that had a murky transparent color. Another deduction we came to was the white dots that ran along the body all the way to its tail could be bioluminescent in nature like an angler. The pectoral fins were small and thin like a tooth pick. The final detail we took note of was the silver patch underneath its eyes.It was a type of angler fish we hypothesized. And it somehow ended up on the surface. There were several questions we voiced to each other: if it is a deep angler fish, how did it end up here? Where did it come from? Was it stunned by the sperm whale’s echolocation and pulled upwards as it surfaced? Later that night as we went through our faecal samples, photo IDs and data entry, the search began for what exactly this organism was. Jack did some image trickery and overlapped the photos with an alien from Alien. Scaleless Black Dragonfish c/w Alien - BMMRO Abaco

Scaleless Black Dragonfish c/w Alien - BMMRO Abaco

I personally thought it looked more like Venom from Spiderman. As he did that, I took it upon myself to begin the search by looking up the most prominent feature: the angler on the anterior ventral side of the fish. By using this characteristic, I was able to narrow the organism down to a Scaleless Black Dragonfish by using several online scientific key identification guides and forums. The species we are still unsure about. The mystery continues…

This creature is one of a number of dragonfish species found worldwide. This one might to be one of the genus Melanostomias (says he, hesitantly…). Like many deep sea creatures, its customary depths are pitch black, or nearly so; and so it is equipped with its own light source (bioluminescence), including the item dangling down from its lower jaw, called a barbel. The fish’s glow and no doubt the gleam of the barbel swaying around in the water act as a lure to attract prey that swim up to investigate and then.. snap! Those teeth start to do their work.

Scaleless black dragonfish (Melanostomias biseriatus) (imagesource.com)

I’ll end with an amazing short (2:28) video posted in early 2014 by ‘Indoona’. The accompanying description is the most authoritative account of the species and its little ways that I have come across, complete with useful links. I include it before the video, noting only that the creature featured is a Pacific one from off the coast of California, and therefore not identical to the Abaco one.

THE DEEP SEA DRAGONFISH OR VIPER FISH is an awesome looking creature from the middle depths of the ocean (this one comes from 600 metres or about 1000 feet deep). Also called the scaleless dragonfish, they are ferocious predators, with extremely large teeth compared to their body size. And they have one of nature’s most amazing tricks to give them the edge over their prey (more below).

There are several different species of dragonfish (one estimate is 67 species – all from the fish family known as Family Stomidae) and they are quite difficult to tell apart but this one is from the pacific depths of California and is likely Tactostoma macropus, the longfin dragonfish. Idiacanthus antrostomus is an Atlantic species that looks very similar – at least I think that’s the case correct me if I’m wrong.

They hunt with a bioluminescent barbel or lure. It is not glowing here but under the different lighting regimes I used – some of the darker images – you can see how much the lure stands out.

Sadly fish like this do not survive long on the surface, mainly because of temperature differences and mechanical damage in the net rather than pressure problems I think. It was caught in a cod-end trawl and filmed in a special tank (a kreisal aquarium). But is great to be able to share another wonder of the oceans on YouTube.

And their amazing trick? Unlike most other deep sea creatures which are sensitive to blue light – the dragonfish also produces a red light beam (see the organ to the rear of the eye) – it is also very sensitive to red light. Although red light does not travel very far underwater it allows them to see when other animals cannot and to sneak up on their prey – especially shrimps that glow in the red light. For more detail see: http://www.science-frontiers.com/sf10… and the work of Ron Douglas and Julian Partridge,http://blog.wellcomecollection.org/ta… (these images were filmed with the help of Julian and Ron). Oh and this dragon is not big – about 20 cm or just under a foot!

[youtube https://www.youtube.com/watch?v=i6cIoj7c2FI]

Credits: Luanettee Colebrooke, ‘Jack’ & BMMRO (to whom thanks as ever), imagesource.com, Indoona , and 2 sites I came across during my investigations – seasky.org & strangesounds.org

If you can’t get enough of dragonfish, check out this Tumblr site for dozens of images including photos, drawings, cartoons, and enough strange dragonfish-based characters to weird you out utterly… HERE