The Black Grouper is a large fish of the reefs found in the western Atlantic, particularly in the waters of Florida, Bahamas, Caribbean and the Gulf of Mexico. It is a solitary species that mostly prefers the shallow waters around coral reefs.
Formerly plentiful, these groupers (like other grouper species) have moved from an IUCN listing of ‘Least Concern’ to ‘Near-Threatened’. They have the twin disadvantages of being fished for sport and fished for food. As demand for grouper on the menu rises, so does its vulnerability. The species is described as a ‘slow breeder’, so a depleting population has less chance of sustaining numbers.
An adult black grouper’s diet consists of small fish and squid. Juveniles feed primarily on crustaceans. However, certain tiny reef fish are important to the species as ‘cleaners’. You can read about their significance by clicking CLEANING STATIONSHere are examples of two black groupers receiving attention at the same cleaning station. Both also seem to be giving a ride toREMORAS.
Note that this fish has an embedded hook and is trailing a line – one that ‘got away’
Despite the name, black groupers are not all black. They have many shades from dark to olive-coloured to pale. I believe the two photos below are of a grouper known as Arthur, a favourite with divers and definitely off the menu…
The tiny bright blue fish in the photo above are Blue Chromis, a regular accompaniment on any snorkel or dive on a reef. I like the colourful little Fairy Basslet in the next photo
Now that the NASSAU GROUPER has been awarded a closed season to help maintain numbers, it will be interesting to see if the winter fishing ban is extended to the Black Grouper…
MAPPING ABACO: READ A NOVEL, TALK RUBBISH OR DISAPPEAR
I am probably the last person to twig the topological significance of Abaco’s location in the world. An email tipping me off about a TV programme led me to investigate further. There turn out to be 3 ways in which Abaco’s position in the Atlantic Ocean is of special interest. Two are geographic fact; and one is located in the grey area between myth and putative evidence-based supposition (if such a nebulous concept exists…). If everyone knew this already, sorry for being so late into the game. But you get some nice maps to look at, gratis, like the wonderful van Keulen map of 1728 above. About the only marked location on Abaco is ‘Hole Rok’ (now ‘GAP ROK’). For a history of Hole-in-the-Wall in historic maps, click HERE
1. THE DISAPPEARING TRICK?
Until the recent email, I hadn’t taken on board that Abaco is within the Bermuda Triangle. The island and its cays are contained snugly into the 60º tip of the western angle of an equilateral triangle based on Bermuda, Miami and Puerto Rico. The NOAA map below could not be clearer: Abaco is squarely within the triangle, if that is geometrically possible.
I wrestled with whether to write an earnest discourse along the lines “Towards a Greater Understanding of Triangle Phenomenology”. Then I thought, Nah! If it’s a myth, what’s the point in examining its credibility. If it’s all true, I would’t want to worry you more than I already have by mentioning it… So you can do the hard graft if you wish by checking out the links below. Or you can just move on to section 2. Or relax in the sun, go fishing, find some nice birds, or have a Kalik or 3.
THE WIKI ANGLE Excellent potted overview dealing with supposed position, the main ‘unexplained disappearances’, and the possible causes of these – both natural and supernatural. Frankly, this should do it for all but the most persistent, who probably are more widely informed already.
SCIENCE CHANNEL The top ten Bermuda Triangle theories. Note: may not include your own pet theory of aliens from Planet Tharkron with their Pukotic Missile Rays
HISTORY.COMComes complete with spooky-music video presentation. NB blurb nails its colours to the mast by using words like ‘Mythical’ and ‘Fanciful’ so if you are a believer you won’t want to go here, I suspect.
TEN WEIRD FACTSAn informative video for those who want a bit more sensation.
2. WHAT A LOAD OF RUBBISH
Rowing through the Great Atlantic Garbage Patch (sandiego.surfrider)
Abaco also finds itself at the western edge of the Northern Atlantic Gyre. Strictly speaking the Gyre comprises a combination of four main currents: the Gulf Stream in the west, the North Atlantic Current in the north, the Canary Current in the east, and the Atlantic North Equatorial Current in the south. It is not synonymous with the infamous North Atlantic Garbage Patch, which is contained within the geographical boundaries of the Gyre. The top image gives a broad-brush idea of the central area of concentration of the Garbage Patch within the Gyre. Abaco looks to be well clear of trouble. But don’t be too optimistic.
North Atlantic Garbage Patch (12Degreesoffreedom)
Looking at various sources, there is some variation in the precise boundaries of the Gyre, though Abaco is plainly within it. Q: is it safely beyond the edges of the plastic peril? A: as any resident will know, the naturally pristine beaches tell a tale of constant plastic and other debris brought in on the high tide almost daily. The incidence depends to an extent on weather and wind direction, but the overall picture is of a relentless intrusion of rubbish on golden and white sand expanses. There is an extent to which what the tide giveth, the tide taketh away; and of course many beaches are scrupulously kept clean. NB I’m not trying to propagate anti-visitor publicity – many people will have experienced the same situation elsewhere.
North Atlantic Gyre Garbage Patch (wired.com)
The research map above shows that, although the garbage hotspots and warmspots are well away from Abaco, the ever-widening circulating soup of plastic, rubber and metal has reached the island. Abaco is in the pale blue zone. Yellow is not that far off. Imagine what the orange or red areas must be like. This sort of thing:
In some places the junk stacks up to form islands with hills
Texas has become a standard ‘unit’ for large area comparisons. I notice that several sources describe the main area of the NA Garbage Patch in terms of Texas. But how big is that (BIG!)? To get an idea, I created a map overlaying Texas on an area centred on the Bahamas. So, Texas is this big…
I’ve got more about some very specific rubbish to discuss another time, so I’ll leave you with the most interesting piece of marine debris to wash up on the Delphi Beach, a 12 ft ROCKET FAIRING from the Mars ‘Curiosity’ launch! Click link for more details.
3. A NOVEL PLACE TO BE?
The Sargasso Sea is named for theSARGASSUMseaweed found in large concentrations in the area. Columbus was the first person to sail right across the Sea, in 1492 (well, he and the crews of his 3 ships Niña, Pinta, and Santa Maria). He noted the large areas of seaweed that his expedition’s ships had to plough through. Eventually he made landfall on San Salvador, Bahamas.
This fine Krümmel map from 1891 shows the extent of the sea, and you’ll see that its western fringes reach the ocean side of Abaco. Have you seen the seaweed pictured below the map? That’s Sargassum.
Sargasso See Map – Krummel -1891
A close-up of Sargassum – maybe it washes up on a beach near you…
EIGHT FACTS ABOUT THE SARGASSO SEA TO IMPRESS YOUR FRIENDS
Jean Rhys’s famous 1966 novel ‘The Wide Sargasso Sea’ is actually set in Jamaica (nb the Sea is mentioned!)
The Sargasso is the only ‘Sea’ to have no land boundary, being entirely in the Atlantic Ocean
It is vital to mass migrations of eels, where they lay their eggs
Young loggerhead turtles are believed to head for the Sea for seaweed protection while they grow
Much of the debris trapped in the NA Garbage Patch is in the Sargasso, and is non-biodegradable plastic
The Sea is protected by Commission established in 2014 involving at present 5 countries, including (unbelievably) Monaco, the second smallest country in the world at 0.75 sq miles. Green Turtle Cay is about twice the area!
Cultural references include the track “Wide Sargasso Sea” on Stevie Nick’s “In Your Dreams” (2011)
There are loads of other literary & musical references but I lost the will to pursue them when I saw the inclusion of ‘Dungeons & Dragons’
If you want to find out more about Jean Rhys’s novel, read it or clickHERE
MUSICAL DIGRESSION
While writing this post I have had a song thrumming annoyingly inside my head. It’s ‘Bermuda Triangle’, with its coyly rhyming ‘look at it from my angle’. Now it’ll be inside your head too! I couldn’t remember who it sang it. Rupert Holmes? No, that was the egregious “Escape (The Piña Colada Song)” (1979). Ah yes. Barry Manilow. Bazza Mazza. The Bazzman. As you’ve finished with the maps etc, here’s a musical memory with a counterbalance of the Stevie Nicks song mentioned earlier…
Those cover the Triangle and the Sargasso; what of the Garbage? Try some Fresh Garbage from Spirit…
OPTIONAL MUSICAL NOTES Randy California’s fingerpicked intro to ‘TAURUS‘ is remarkably similar to the later, far more famous guitar work of Jimmy Page’s intro to ‘STAIRWAY TO HEAVEN‘. And Spirit happened to tour with the early Led Zep. Legal action was commenced last year for copyright infringement, as yet unresolved… You be the Judge!
Credits: As credited above; open source; NOAA; mail.colonial; telegraph.co.uk; Sandy Walker;Bogdan Giușcă, Youtube self-credited; Wiki; Random Researches and Magpie Map & Fact pickings
Last year held hopes of a joyous reunion – and indeed union – in Abaco waters between young manatees Randy and Georgie. He had taken the trip from the Berry Is., around the top of Abaco and down the east coast as far at Little Harbour. She lives in Cherokee. Tantalisingly close. But then Randy retraced his steps as far as Gorda Cay and hopes for the production of Abaco’s first manatee calf (at least, in living / recorded memory) turned to seagrass mulch. The poignant story and some great manatee close-up photos (including a ‘selfie’ of sorts on a Go-Pro) can be foundHERE
But manatees do breed elsewhere in the Bahamas, in particular the Berry Is. They also seem to favour the north end of Eleuthera, and have been seen on Andros and NP. True, the absence of significant freshwater sources in the Bahamas – an essential part of their diet – doesn’t make for an ideal habitat, but manatees do pair off and Bahamas calves are born. In summer 2012, there were four resident West Indian Manatees (Trichechus manatus) living in Great Harbour Cay, Berry Is. The adult female, Gina, had been there for 3 years – she originated from Florida. She had reportedly had 3 or 4 calves and was caring for her latest, a female calf called JJ, born in the late winter of 2011.
Adult female manatees are sexually mature at 6-10 years of age and have a gestation period of up to 13 months. The first two years of a calf’s life is spent with its mother. During this time they are taught where to find food, fresh water, warmth and shelter. Generally, after two years the calf is weaned and separates from its mother (see header image of Gina and JJ during that process)
Nursing a growing JJ
Now there is more good news for Gina, who has been under regular observation by the BMMRO. At the turn of the year, Gina was re-tagged in Harbour Island, Eleuthera. As reported, “she looks well, was very calm and is very pregnant… If the tag comes off and is found, please call the number on the tag to let us know – we are now monitoring her movements via the internet”.
Gina’s shows her best side
Coming atcher…
Tell-tale signs (to experts, anyway) of advanced pregnancy
I will post any further news about Gina as it arises. Meanwhile, for more information about West Indian manatees, you can visit the MANATEE PAGE. There are several links there to specific manatee stories, especially about Rita and her adventurous daughter GEORGIE, Abaco’s current favourite (indeed, only) resident manatee… Both Links need an update, I notice – they don’t cover Georgie’s subsequent return to Abaco and her contented settling down again in Cherokee where she seems happy as a… sirenian.
Credits: All photos and primary fount of Bahamas manatee knowledge: BMMRO; Magpie Pickings
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.
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.
A flounder’s eyes can move independently of each other. One may look forwards, the other backwards
‘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)
Check out these imitative patterns in Bahamas waters…
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…
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 on a plate – Kim Rody Art
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
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.
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, CLICKNICE 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.
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.
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! ContactBahamas Marine Mammal Research Organizationwith 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 RANDYarrived 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…
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.
Credits: BMMRO & FOTE with thanks as ever for use permissions
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 theIUCN Red Listas an Endangered Species and is also a USNational Marine Fisheries ServiceSpecies 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.
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 grouper
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.
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!
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 humans. People 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.
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 itsPostal 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.
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.
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…
Credits: Melinda Riger, Rick Smit, Open Source, BNT, BREEF, Wikimedia, Bahamas Postal Service
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 SPONGE
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.
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.
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”.
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…
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!
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!
Doh! Reading through this after posting I can’t remove from my mind the likeness of Homer Simpson on the snail in Melinda’s photo (2). I had to check it out and… it’s uncanny!
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 outTHREATS 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 GALLERY
(thanks as ever to Melinda Riger of Grand Bahama Scuba, but for whom etc)
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…
TheSEA TURTLE CONSERVANCYhas 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.
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
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…
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.
‘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.
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…
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
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“).
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.
“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. 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.
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!
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
WTF? (WHAT’S THAT FISH?) 2: STRANGE BAHAMAS REEF FISH
WTF 1 concerned the REMORA, the upside-down looking fish with the trainer-sole sucker on its head with which it attaches itself to sharks and other large undersea creatures. If you’ve ever seen a picture of a shark with one or more grey passengers hitching a ride, those are these.
WTF 2 features some creatures found in the reef waters of the Bahamas that make you wonder just how and why they are as they are. They look unnecessarily complicated, and the design is somewhat outlandish. See what you think of these…
BURRFISH
SLIPPER LOBSTER
SCORPIONFISH (& header image) camouflaged against coral
COWFISH
TRUNKFISH
PORCUPINE FISH
“Watch this…”
“Ta Daaaaaa”
AIRPLANEFISH*
*Well, it’s really airplane wreckage. Besides a few other planes and a variety of ships that can be explored underwater, there are also two locomotives in Abaco waters that “fell off” a ship while being transported. Now recreate in your mind the subsequent conversation with an insurance company…
APOLOGIES Header image repeated to sort out FB visuals problem that’s driving me nuts
Credits: Melinda Riger, Grand Bahama Scuba;Virginia Cooper; itsnature.org
I’m feeling distinctly crabby right now. In a skilled move that would impress the Bahamas utility providers, the UK’s very own much-vaunted BT selected us for the privilege of being unplugged from the grid last week. From the time of reporting the problem, it has taken them 6 days to plug us back in. It’s a little reminder of the far more persistent Abaco experience! No landline, no wifi, no email for almost a week. To begin with, it was a light relief. After nearly a week, not funny anymore. Here are some nice crabs in conchs to celebrate getting back online while reflecting my crabby mood.Find out more about Hermit Crabs – in particular crab racing at Delphi and the intricate rules – here:WACKY RACES AT DELPHI
‘SPOTTED IN ABACO WATERS’: PANTROPICAL SPOTTED DOLPHINS
The BMMRO has posted several reports of dolphin and whale activity around the coast of Abaco during August, with some outstanding photos to accompany them. I had been going to post rather generally about this until a couple of days ago, when an unusual dolphin species for the region was… er… spotted and some memorable images taken.
These are PANTROPICAL SPOTTED DOLPHINSStenella attenuata, whose range encircles the globe but at a lower latitude than the far more frequently encountered resident ATLANTIC SPOTTED DOLPHINS Stenella frontalis. Here are comparative range maps. The rarity of the Pantropical species in the Bahamas is indicated in the BMMRO report of a stranding in 2011 – see below.
The pantropical image below is from the BBC archive and not taken in the Bahamas. I’ve included it for illustrative purposes due to the close-up underwater view of the dolphin.
This wonderful underwater video of pantropicals is by Jake Levenson, shot from a polecam. Although it is 6 minutes long, I highly recommend it for (a) the stunning views of these creatures at very close quarters (b) the excellent audio quality – you can clearly hear the dolphins communicating with ‘sonar’ clicks and squeaks, and (c) the strange sense of peace you may feel when you have watched it.
[youtube http://youtu.be/-hXTYe58g34]
PANTROPICAL SPOTTED DOLPHIN STRANDING 2011
In May 2011 a dead dolphin was found on the sandbank at Casaurina Point, Abaco. BMMRO’s scientists established that it was a sub-adult male pantropical spotted dolphin with a stomach full of squid beaks, a known prey for the species. A full necropsy was conducted on the animal and samples were taken for scientific testing to determine the cause of death. At the time the BMMRO reported the find in their quarterly Newsletter:
Pantropical spotted dolphins are commonly found in off-shore waters, although they can be found close to Abaco’s coastline due to the close proximity of deep waters. They can occur in large group sizes of up to 100 animals. Adult males and females reach up to 2.6 m (8.5 ft) and 2.4m (7.9 ft) in length, respectively. Since our efforts began in 1991, BMMRO has records of only 28 sightings of pantropical spotted dolphins in The Bahamas(my rubric), although their cousin species, Atlantic spotted dolphin, is a common resident. This is the first recorded stranding of this species in The Bahamas.”
‘TREAT WITH PATIENCE…’ – NURSE SHARKS IN THE BAHAMAS
The scientific name for the nurse shark sounds like something Bilbo Baggins might have said to summon elves to his rescue: Ginglymostoma cirratum. Actually the name is a mix of Greek and Latin and means “curled, hinged mouth” to describe this shark’s somewhat puckered appearance. The origin of the name “nurse shark” is unclear. It may come from the sucking sound they make when hunting for prey in the sand, which vaguely resembles that of a nursing baby. Or it may derive from an archaic word, nusse, meaning cat shark. The most likely theory though is that the name comes from the Old English word for sea-floor shark: hurse.
Nurse sharks are slow-moving bottom-dwellers and are, for the most part, harmless to humans. However, they can be huge—up to 14 feet (4.3 meters)—and have very strong jaws filled with thousands of tiny, serrated teeth, and will bite defensively if stepped on or bothered by divers who assume they’re docile.[There are recorded instances of injuries caused to divers who have tried to pull nurse sharks by the tail. And serve them right, I say. Treat them with patience – and respect!]
Notice that the nurse shark in the above photo, and in the header image, is being attended by REMORAS. Click the link to find out more about the strange relationship these ‘weird suckers’ have with larger marine creatures.
They use their strong jaws to crush and eat shellfish and even coral, but prefer to dine on fish, shrimp, and squid. [And also stingrays, apparently. They have been observed resting on the bottom with their bodies supported on their fins, possibly providing a false shelter for crustaceans which they then ambush and eat.] They are gray-brown and have distinctive tail fins that can be up to one-fourth their total length. Unlike most other sharks, nurses are smooth to the touch.
Nurse sharks are found in the warm, shallow waters of the western Atlantic and eastern Pacific oceans. They are abundant throughout their range and have no special conservation status, although the closeness of their habit to human activities is putting pressure on the species.
Nurse sharks are nocturnal and will often rest on the sea floor during the day in groups of up to 40 sharks, sometimes piled on top of each other.
FAST FACTS
Type: Fish
Diet: Carnivore
Size: 7.5 to 9.75 ft (2.2 to 3 m)
Weight: 200 to 330 lbs (90 to 150 kg)
Size relative to a 6-ft (2-m) man:
Credits: All photos Melinda Riger, Grand Bahama Scuba; range map and text mostly NATIONAL GEOGRAPHIC filled out with other pickings
‘ELEGANTLY WEIRD’ – SPOTTED DRUMFISH JUVENILES: BAHAMAS REEF FISH 20
I’ve posted before about the rather extraordinarySPOTTED DRUMFISH, one of those reef fish which in juvenile form is very different from the adult. This species was first up in the Bahamas Reef Fish series – click above link. Here are a few recent images, courtesy of Melinda Riger. The first three show the juvenile form (note the piscine photobomb in the first one). The last shows a group of adults hanging out on the reef with (I think) some soldierfish. You can see how the juvenile drumfish becomes the adult, but those little stripy bullet-heads with their two long elegantly trailing appendages differ considerably from the rather solid-looking spotty / stripy adults with their dramatic punko-rockabilly quiffs.
CETACEAN SENSATION: SPERM WHALES & DOLPHINS ON ABACO
July has been ‘Whale Camp’ month for the BMMRO, when a small group of lucky youngsters get to spend time out at sea searching for whales and dolphins, and learning the intricacies of data recording and research. One target was the sperm whale, a species that may be found off the coasts of South Abaco. This is a favoured place because the deep trench of the Great Bahama Canyon throws up the food these whales need (see map below).
After some time spent searching, the BMMRO reported “the sperm whales are back! We found a single animal yesterday, and finally in the evening found the rest of the group, 10+ animals including 3 mother-calf pairs, and dolphins at Rocky Point!” Here are some of the photos from the trip.
This map of the northern Bahamas shows the V-shaped tails of the Great Bahama Canyon, and explains why the east coast and (in particular) the shallower south-west coast between Hole-in-the-Wall and Rocky Point is so attractive to feeding whale species.
The dolphins were quite prolific in July, in particular bottlenose and spotted dolphins. These photos were mostly taken while the search for sperm whales was going on: the BMMRO posted“lots of dolphins up at Gorda Cay yesterday… still not hearing any sperm whales in the area, has been a couple of weeks without sign of them so they should be showing up again soon…”As they obligingly did!
Today is the first day of the crawfish season and Facebook Abaco has been crawling with crawfish for a couple of days in feverish anticipation. So I decided to stick with whales and dolphins instead because there are enough crawfish images out there to keep anyone happy. However I did particularly like this offering today from Albury’s Ferry Services, always a byword for tastefulness and decorum. I’ve borrowed their picture (they borrow mine sometimes) – I wondered if it need a little more exposure, then decided there was probably quite enough already….
RED REEF RESIDENTS: A RUFOUS ROUND-UP IN THE BAHAMAS
It’s sunny and very hot. Time to take another dive with Melinda to see what is going on under water around the reefs. Here are some residents, a somewhat loose description since some of the denizens featured are not especially active. But they are alive, so they qualify by my wide rules. And please may we not get into a discussion about where precisely red and orange overlap. It’s a grey area. And it’s too hot to argue about it… Let’s start with three types of GROUPER that may be spotted in the northern Bahamas. In fact, they are always spotted. One of my favourite pictures is the Graysby – it’s such a great expression, and he really rocks the spots!
GRAYSBY
TIGER GROUPER AT A CLEANING STATION with Peterson Cleaning Shrimps & a GobyRED HIND
BLACKBAR SOLDIERFISH
HOGFISH
SQUIRRELFISH
But red fish are not the only red reef residents. Here are some that won’t swim away from you as you swim towards them to admire them…
Few people know that, by international law, it is unlawful to fail to be fascinated by Octopuses… Octopi… Octopodes… Octopotomi… Whatever. For a learned dissertation on the correct plural form for these creatures – bear with me, there are strict rules that apply here – you’ll find out the right way atTHE PLURAL OF OCTOPUS. I won’t go into it all now, because it’s time to showcase some more wonderful underwater photography by Melinda Riger of Grand Bahama Scuba. Strictly, these are not Abacos Octos, but they share the same reef system and are therefore close cousins. Of such tenuous links are blog posts formed.
My favourite octopus photo
Settling down to a take-away
The all-seeing eye…
On the move… so long suckers!
Octopus InkAll photos: Melinda Riger
The Rare Scottish Tartan Octopus
SAD POST SCRIPT: As a Scot out of Norway (did you ever?) my father learnt to play the bagpipes. Indeed had a set. They lived in a cellar I wasn’t allowed into. The bag was allegedly preserved in treacle (don’t ask). I still have the ‘Chanter’ (a single pipe practice instrument), the sound of which is akin to trying to strangle one cat with another cat. I was fobbed off with that. Then one day as a treat the cellar was unlocked and a large wooden box was dragged out. The bagpipes! The lid was opened and… OMG! the bag had rotted away completely, the pipes looked pathetic and very disappointing, and the whole thing stank of nameless dead creatures… I can’t hear the sound of the pipes to this day without finding it (a) stirring yet (b) enough after a short time and (c ) a reminder of a broken dream… The end.
‘TAKEN TO THE CLEANERS’: REEF FISH & CLEANING STATIONS
A cleaning station is a place where fish and and other aquatic life congregate to be cleaned. This involves the removal of parasites both externally and internally, and is be performed by various creatures including, on the coral reefs of the Bahamas, cleaner shrimps and various species of cleaning fish such as wrasses and gobies. The process conveniently benefits both the cleaned and the cleaner.
Tiger Grouper being cleaned by Cleaner Shrimps
Blue Parrotfish being cleaned (or tickled, from its expression) by a Cleaner Shrimp
Black Grouper being cleaned by gobies – note the ones in its mouth
Black Grouper at a Cleaning Station with gobies. Note the hook and line…
Tiger Grouper being cleaned by Gobies
Gobies checking a hand for parasites….
When a fish approaches a cleaning station it will open its mouth wide or position its body in such a way as to signal that it needs cleaning. The cleaner fish will then remove and eat the parasites from the skin, even swimming into the mouth and gills of the fish being cleaned.
“Clean me!” An amazing view of a Tiger Grouper at a CleaningStation with its gills wide open
Grouper at a cleaning station over a sponge
Remora clinging to a shark. For more on this unusual symbiotic relationship, click HERE
All photos: Melinda Riger of Grand Bahama Scuba, with thanks as ever
AMAZING WHALE, DOLPHIN & MANATEE PHOTOS FROM ABACO
TheBMMRO(Bahamas Marine Mammal Research Organisation) had a great June for sightings of cetaceans and sirenians. Here is a sample of their wonderful photos from recent research expeditions (with thanks as ever for use permission).
RANDY THE WEST INDIAN MANATEE
After the recent excitement of Abaco’s manatee GEORGIEhaving returned to Cherokee after another of her epic journeys, another West Indian manatee has arrived at Sandy Point (conveniently the location of the BMMRO HQ). Sirenians and cetaceans are generally recognised from particular patterns to flukes or fins. The second image shows the notch in Randy’s tail that confirms ID.
BOTTLENOSE DOLPHINS
SPOTTED DOLPHINS
BLAINVILLE’S BEAKED WHALES
TWO COMPLETE FLUKES (THIS IMAGE & HEADER)
(note minor damage to the edges, from which ID of an individual can be made)
SPERM WHALE & DIVER
Compare the diver’s fins in the foreground with the (partial) length of a huge sperm whale…
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