PEACOCK FLOUNDER: BAHAMAS REEF FISH (21)


  Peacock Flounder ©Melinda Riger @ GB Scuba

PEACOCK FLOUNDER: BAHAMAS REEF FISH (21)

PEACOCK FLOUNDER or PLATE FISH Bothus lunatus

I have briefly featured this fish before in the context of its extraordinary camouflage abilities; and also its interesting ocular arrangements. Time to give it another swim around, I think, with some additional photos that I have collected.

Peacock Flounder

Bothus lunatus is the Atlantic / Caribbean version of a species also found in the Pacific and Indian oceans. Adults may grow up to 18 inches long. The species is a ‘lefteye’ flounder, with both eyes on its left (top) side & its right side underneath.  However a baby flounder looks & swims like normal fish, with bilateral eyes. As it grows, the right eye gradually ‘moves’ round to the topside, and it becomes a flatfish.

Peacock Flounder

A flounder’s eyes can move independently of each other. One may look forwards, the other backwardsPeacock Flounder Eye ©Melinda Riger @ G B Scuba

‘NOW YOU SEE IT…’ CAMO-FISH

The Peacock Flounder has extraordinary  colour-changing powers, and can rapidly vary its background colour to make it closely resemble that of its surroundings. This enables it camouflage itself as it lies on the seabed. It can change coloration completely in between two to eight seconds.  

Four frames of the same fish taken a few minutes apart showing the ability of flounders to change colors to match the surroundings (Wiki)Peacock Flounder Brocken Inaglory

Check out these imitative patterns in Bahamas waters…Peacock Flounder (f) ©Melinda Riger @ Grand Bahama Scuba

Flower_flounder_in_Kona_wiki

There are two advantages to the ability to camouflage (‘cryptic coloration). One is obviously to avoid detection by predators. The other is to enable the flounder to ambush its meals. They feed primarily on small fishes, crabs and shrimps, lying concealed on the seabed and grabbing any unwary prey that ventures too close. They will even partially bury themselves in the sand, leaving just their eye-stalks keeping watch…Peacock Flounder ©Melinda Riger @ Grand Bahama Scuba

HOW CAN THEY POSSIBLY CHANGE COLOUR SO QUICKLY?

Scientists are still puzzling this out. In a conch shell, it seems the flounder can coordinate its amazing all-round vision with its hormones, instantly releasing certain pigments to its skin cells and suppressing other pigments to make the colour match. Not convinced? Then watch this short video and prepare to be impressed. 

Fred Riger of Grand Bahama Scuba, who kindly keeps a benign eye on my reef fish posts (he’s the expert), adds a third excellent reason for coloration changes: sex… “the male peacock flounder can, and does greatly intensify his colors, presumably to declare territory and attract females to his person. When doing this the males will also signal with the left pectoral fin, sticking it straight up and waving it around.” Maybe that is what is going on in the photo below – intensified, non-camouflage colours, and a raised fin…Peacock Flounder ©Melinda Riger@ G B Scuba

Credits: Melinda Riger of Grand Bahama Scuba for almost all photos; wiki for 2 illustrative images

MAKING A SPLASH: SPERM WHALES & MANATEES IN ABACO WATERS


Sperm Whale, Abaco Bahamas (BMMRO)

MAKING A SPLASH: SPERM WHALES & MANATEES IN ABACO WATERS

After a quiet spell on the cetacean and sirenian front, there is exciting news to report. First, the BMMRO encountered two sperm whales just off Sandy Point.  I don’t know how close to the shore they actually were, but it was very friendly of them to come so near to the BMMRO HQ.Sperm Whale, Sandy Point, Abaco BMMRO3

When whales are sighted from the research vessel, one of the tasks is to collect feces. This job is often undertaken by interns, and is a good way to learn that serious research may well involve unattractive work… They practise with… er… coffee grounds and a net. For more on this important yet unappealing aspect of whale research, CLICK NICE TO SEE FAMILIAR FECES. Another essential part of any sighting is to take fluke photos to enable ID.  Every whale has different and distinctive patterning to the fluke, including general wear and tear. As a photo archive is built up, the researchers are able to recognise a particular whale and cross-reference it with previous sightings.

Sperm Whale, Sandy Point, Abaco BMMRO2Sperm Whale, Sandy Point, Abaco BMMRO1

The third task of a sighting is to record clicks made by an individual whale. This enables an estimate of the whale’s size to be made, and again a sound archive is gradually built up from which comparisons can be made.

Sperm Whale, Sandy Point, Abaco BMMRO4

A NEW MANATEE VISITS MARSH HABOUR

FRIENDS OF THE ENVIRONMENT has just reported the sighting of a new manatee at the head of Marsh Harbour harbour. I’m not aware of any other sightings in the last couple of days, but as they say,  “Please keep your eyes out and drive carefully! Contact Bahamas Marine Mammal Research Organization with any further sighting reports by calling 357-6666. You can also share photos with them on Facebook. Also, please do not feed the manatee. They are able to find their own food and anything else may make them unhealthy”.

This is Abaco’s third recent manatee. First there was GEORGIE, who as far as I know is still comfortably settled in the Cherokee area. Then RANDY arrived earlier this and got to within about a few miles of Georgie… High hopes of a meeting – and ‘friendship, maybe more’ – were dashed when Randy turned round and headed back to Castaway Cay. Let’s hope this newcomer stays around. I wonder what he – or she – will be named? My suggestion is Abby or Abi, which I think is unisex…

10846213_10152589661493178_5080839733543438859_n10849995_10152589661598178_1824081022417510310_n

Just as with the whale flukes, the tail of a manatee is an important means of identification. The new manatee’s tail has its own distinctive edge pattern, which will enable its future recognition. Here is an image of Randy’s tail, with its unique notch. 

Randy the Abaco Manatee - tail notch

Credits: BMMRO & FOTE with thanks as ever for use permissions

mantsw~1

NASSAU GROUPER: VULNERABLE, ENDANGERED… & NOW PROTECTED


Nassau Grouper ©Melinda Riger @ GB Scuba copy

NASSAU GROUPER: VULNERABLE, ENDANGERED… & NOW PROTECTED

The Nassau grouper Epinephelus striatus is one of a number of Caribbean grouper species found generally in the Northern Bahamas and specifically in Abaco waters. Others include the Black, Tiger, and Yellowfin groupers, the Red Hind,and the Graysby. The Nassau grouper is special, however, not least because (unlike the others) it is on the IUCN Red List as an Endangered Species and is also a US National Marine Fisheries Service Species of Concern. It is considered the most important of the groupers for commercial fishing in the Caribbean, and the IUCN listing data suggests that a population decline of 60% occurred over the last three generations (27-30 years), a startling rate. The current population size is estimated at >10,000 mature individuals.

Nassau Grouper ©Melinda Riger @ G B Scuba copy 2

The Nassau Grouper is a creature of the coral reefs in the Caribbean and adjacent seas, though it can also be found in deep water. It feeds in the daytime on small fish and small crustaceans such as shrimps, crabs and lobsters. It lurks in caves and recesses in the reef, sucking in the prey that passes unsuspecting by. The coloration of an individual fish may vary considerably with conditions, and it can adapt its colour to its surroundings as camouflage.  

Tiger grouper meets Nassau grouperNassau & Tiger Grouper ©Melinda Riger @ Grand Bahama Scuba  copy

Spawning takes place in December and January as the seawater cools, always at full moon, and always in the same place. In the moonlight, huge numbers of the grouper gather together to mate in a mass spawning aggregation. This may continue for several days. However, the species is slow breeder, which is why overfishing is particularly damaging to the population as the depleted stock cannot readily be replaced.

3846_aquaimages Wiki

CONSERVATION ISSUES

There are other besides factors commercial overfishing that make the Nassau grouper so vulnerable, including fishing during the breeding season; taking undersized fish; pollution and reef decline; habitat loss; and invasive species. The spawning areas are especially vulnerable to exploitation. In the Bahamas, as elsewhere,  the government has now instituted a closed fishing season for the Nassau grouper. Here is the BREEF  flyer, just circulated – and in fact the reason for this post, which reminded me that I had planned to write about this fish! 10382222_10152869346685953_7443797899832698038_o

THREATS

The Bahamas National Trust sums up the multiple threats in this uncompromising way:

Nassau grouper is eaten by barracudas, lizard fish, dolphins, sharks and other large predators of the reef community. But the predators that have the biggest impact on the grouper population are humansPeople are fishing groupers before they can grow to maturity and reproduce. Sex change may also cause a problem. In undisturbed areas there are usually equal numbers of male and females. In heavily fished areas there are often three or more times more females than males. This means many eggs will not be fertilized during spawning. Other threats include, habitat destruction, coral breakage from divers, siltation from construction, runoff from logging and agriculture, dredging, sewage, oil spills and other contaminants that harm coral reefs where Nassau Groupers live.

grouperEpinephelus_striatus_2

There’s an extent to which a country can be judged on its attitude to wildlife from the stamps it chooses to issue. It’s something to do with appreciation and promotion of the country’s natural resources. For example, North Korea rates nil in this respect, with stamps involving scary weaponry, flags, marching and eerily glowing leaders – not a single sparrow to be seen.  By fortunate contrast the Bahamas and its Postal Service score very highly in celebrating the diversity of the wildlife of the islands. The Nassau Grouper was first featured on Bahamas stamps as long ago as 1971, some 25 years before the IUCN Red Listing, and probably before the sharp decline in population numbers had even begun.

bahamas-1971-nassau-grouper-sg-363-fine-used-19448-p

In 2012 the Bahamas Postal Service released ‘a new definitive 16 stamp series’ depicting the marine life of The Bahamas. The Nassau has been promoted from 5c in 1971 to 70c in 2012. That’s inflation for you.

bahamas-marine-life-stamps2

Finally in 2013 BREEF’s 20 years of marine conservation was commemorated with a distinguished and colourful set of 8 stamps, noting in their release: ‘Two of the new stamps feature the Nassau Grouper, a now endangered species that has experienced severe population decline throughout the region… BREEF is well known as an advocate for an annual closed season for the iconic Nassau Grouper during its winter breeding period. The push for the closed season was based on scientific evidence of population collapses throughout the region due to overfishing. BREEF is calling on the government to implement a fixed closed season for the Nassau Grouper in order to protect the species and the fishing industry. The closed season traditionally runs during the spawning season from December 1st until February 28th, to allow the fish to reproduce.  BREEF is calling urgently for the announcement of this year’s Nassau Grouper closed season….’ And so it came to pass… Not only is the Nassau grouper now worth 2 x 65c; it is strictly protected for 3 months during its breeding season. Maybe philately even had a hand in getting somewhere…

BREEF_Comemorative_stamps_PastedGraphic-3

Nassau Grouper (Rick Smit wiki)

Credits: Melinda Riger, Rick Smit, Open Source, BNT, BREEF, Wikimedia, Bahamas Postal Service

FLAMINGO TONGUE SNAILS: ALL YOU NEED TO KNOW


Cyphoma_gibbosum Clark Anderson - Aquaimages

FLAMINGO TONGUE SNAILS: ALL YOU NEED TO KNOW

I wrote about FLAMINGO TONGUE SNAILS Cyphoma gibbous more than two years ago. They have not changed noticeably since then but this site has – in scope, available material and audience. So I am revisiting these small marine gastropod molluscs, which are related to cowries. The live animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the ‘mantle’. The shell itself is usually pale and characterised by  a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and the wider western Atlantic. Whether alive or dead, they are gratifyingly easy to identify.

FLAMINGO TONGUE SNAIL ON A PURPLE ROPE SPONGEFlamingo Tongue on purple rope sponge ©Melinda Riger @ GB Scuba copy

FEEDING ON A CORAL STEM

This snail is snacking on a coral stem, leaving a feeding track behind it. The structural shell ridge is clearly visible beneath the distinctively marked live tissue of these creatures.

Flamingo Tongue LASZLO ILYES Cyphoma_gibbosum_(living)_2

The flamingo tongue feeds by browsing on soft corals. Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore the snail’s feeding preference is generally not harmful to the coral.

Flamingo_Tongue_Snail_on_Soft_Coral_LASZLO ILYES

The principal purpose of the mantle of  tissue over the shell is as the creature’s breathing apparatus.  The tissue absorbs oxygen and releases carbon dioxide. As I have seen it described (unkindly?) “it’s basically their lungs, stretched out over their rather boring-looking shell”. 

Flamingo Tongue, Abaco (Char Albury)

This snail species, once common, is becoming rarer. The natural predators include Hogfish, Pufferfish and Spiny Lobsters, though the spotted mantle provides some defence by being rather unpalatable. Gorgonian corals contain natural toxins and instead of secreting these, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many species.

It comes as little surprise to learn that man is now considered to be the greatest menace to these little  creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the shell of the animal, collect up a whole bunch from the reef, and in due course are left with… “boring-looking shells” (see photos below). Don’t be a collector; be a protector…
Flamingo Tongue, Abaco (Char Albury)

These photos are of flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. You decide!

Flamingo Tongue Snail Shell, Keith Salvesen AbacoFlamingo Tongue Snail Shell, Keith Salvesen AbacoFlamingo Tongue Snail Shell, Keith Salvesen Abaco

Finally, a couple of videos. The first is rather charmingly titled ‘FLAMINGO TONGUES DOING…. SOMETHING’. Any (printable but amusing) suggestions via the Comment box are welcome. The second punchily summarises this post in 30 seconds. Maybe that’s all that was needed!

Image Credits: Clark Anderson, Melinda Riger, Laszlo Ilyes, Charmaine Albury, RH

Doh! Reading through this after posting I can’t remove from my mind the likeness of Homer Simpson on the snail in Melissa’s photo (2). I had to  check it out and… it’s uncanny!

Homer Simpson Flamingo Tongue copy images

TURTLEY AMAZING: HAWKSBILL TURTLES IN THE BAHAMAS


Hawksbill Turtle © Melinda Riger @ G B Scuba

TURTLEY AMAZING: HAWKSBILL TURTLES IN THE BAHAMAS

The Bahamas has breeding populations of 5 of the world’s 7 sea turtle species – Green, Loggerhead, Hawksbill, Leatherback and Kemp’s Ridley turtles (the other two are Olive Ridley – occasionally found in the Bahamas – and Flatback turtles). All are endangered. There’s no getting away from the fact that Man and Man’s activities are now the primary threats. The IUCN ratings below make for sad reading. To see some of the problems, check out THREATS TO SEA TURTLES

Admire the photos here of Hawksbill Turtles Eretmochelys imbricata while you can – the species is IUCN red-listed and I can’t improve on this explanatory display…Hawksbill Turtle Eretmochelys imbricata (IUCN Red List)

HAWKSBILL TURTLE GALLERY

(thanks as ever to Melinda Riger of Grand Bahama Scuba, but for whom etc)Hawksbill Turtle ©Melinda Riger @ G B Scuba Hawksbill Turtle ©Melinda Riger @ G B Scuba copy Hawksbill  Turtle ©Melinda Riger @ Grand Bahama Scuba copyHawksbill Turtle ©Melinda Riger @ GB Scuba copy

I did ask myself whether including this shot might show a lack of sensitivity for the essential dignity of a fine species, infringing its Testudinal rights. But overall, I feel the public interest is best  served by showing it. Anyway, it has plainly discovered something very tasty to get stuck into, so it won’t be unduly bothered. The pair of French Angelfish aren’t going to get a look-in…Hawksbill Turtle ©Melinda Riger @ G B Scuba copy 3

 The SEA TURTLE CONSERVANCY has produced an outstanding series of posters similar to the LOXAHATCHEE posters about corals, conchs, sea grass, bonefish etc. Here is their Hawksbill one, with illustrations by artist DAWN WITHERINGTON. Click the link to reach her website and see her excellent scientific drawings and a lot more besides. This excellent poster contains pretty much all the details you need to hold your own in any hawksbill-related conversation. You can enlarge it by doing that thing with 2 fingers on your track pad thingy.

HawksbillLifeHistoryPoster-STC-DWitherington

I rather like this video from Andros, with the turtle’s gentle tolerance while being approached by a photographer until at last  it decides to move slowly off. The music’s a bit annoying though – it doesn’t really fit the scene IMO. 

Credits: IUCN, Melinda for the fab photos, Sea Turtle Conservancy

‘WTF?’ IN BAHAMAS WATERS (3) : LETTUCE SEA SLUG


Lettuce Sea Slug ©Melinda Riger @ Grand Bahama Scuba copy

  ‘WTF?’ IN BAHAMAS WATERS (3): LETTUCE SEA SLUG

The ‘WTF’ series so far has covered Bahamas reef fish on the bizarre end of the unusual-to-completely-weird appearance spectrum. And it has stood, of course, for ‘What’s That Fish?’. Today, it doesn’t. The feature creature isn’t a fish at all; it looks like a plant; it is in fact a SACOGLOSSAN - specifically the Lettuce Sea Slug Elysia crispata

The head end is on the left…Lettuce Sea Slug ©Melinda Riger @ G B Scuba copy

The name ‘sacoglossan’ literally means ‘sap-sucker’ (the sapsucker bird has a different latin name, however). And the slug’s frilly edges supposedly resemble certain types of curly lettuce. I’ve no idea where the ‘crispata’ comes from, but I am sure it doesn’t relate to crisp lettuce. These are creatures of shallow, clear waters such as the sub-tropical reefs of the Bahamas.

Lettuce_Sea_Slug_LASZLO ILYES

 ‘SOLAR POWERED SLUGS’

This isn’t a technical forum and too much science hurts my head. This species primarily lives off algae. However I give you the word KLEPTOPLASTY to drop into your conversation. In a sentence, algae is eaten but only partially digested; certain elements are stored to produce photosynthesis by which light is converted to energy and the slug can live without food. But baffle your neighbour at dinner, why not, by summarising the process as “chloroplast symbiosis”. Meanwhile, I’m fetching a beer.

Lettuce Sea Slug ©Melinda Riger @ GB Scuba copy

My research suggests that very little is known about the mating behaviour of these slugs. The pair shown below may be exploring the possibilities, or at least trying to work out which end is which. One is easy to tell, but the other? Time to make our excuses and leave…

Elysia_crispata_(Lettuce_Sea_Slug_pair) Nick Hobgood

HOW FAST, EXACTLY, DOES A LETTUCE SEA SLUG MOVE?

This rather beautiful video from ‘CORAL MORPHOLOGIC’ will reveal all. You’ll soon see that progress is very slow. I recommend watching the first 30 seconds and you’ll get the idea. If you choose to persist, you will see the slug sort of turn a corner to the left.

Credits: Melinda @ Grand Bahama Scuba, Laszlo Ilyes, Nick Hobgood, Coral Morphologic, Wiki

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


Scaleless Black Dragonfish - Header - BMMRO Abaco

“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.

BAHAMAS SEA DEPTH MAP (NEAQ)

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“).

Scaleless Black Dragonfish - BMMRO Abaco
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 AbacoScaleless 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.
Scaleless Black Dragonfish - BMMRO AbacoLetting 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 AbacoI 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…Scaleless Black Dragonfish - BMMRO Abaco
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.
                                                                       scaleless-black-dragonfish-mini-jpg          scaleless-black-dragonfish-mini-jpg          scaleless-black-dragonfish-mini-jpg

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!

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

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