CORAL SUNSHINE: PICTURE PERFECT ABACO (9)


CORAL SUNSHINE: PICTURE PERFECT ABACO (9)

coral-in-sunlight-melinda-rogers-dive-abaco

Off the east coast of Abaco lies one of the longest barrier reefs in the world. Some authorities suggest it is the third longest, but the exact ranking of the top dozen coral barriers is a matter for considerable debate. None of the lists I have just checked agree, except that the Great Barrier Reef is the outright winner. I suspect that the problem lies in the loosely generalised description of ‘barrier reef’ and in variations of the appropriate criteria for determining length (it may also depend on who is doing the measuring, of course).

Melinda Rogers of Dive Abaco took this bright sunlit ‘Coralscape’ in the Fowl Cays National Park. It’s a place I have tentatively snorkelled around with great pleasure, despite being in the top dozen most useless swimmers in the world (my appalling underwater videos were disqualified from the rankings for being… rank).

BAHAMAS REEF FISH (51): BLACK MARGATE


Black Margate (Melinda Riger / Grand Bahama Scuba)

BAHAMAS REEF FISH (51): BLACK MARGATE

The black margate (Anisotremus surinamensis) is a type of GRUNT (see also PORKFISH) found among the reefs and rocks of (mostly) the western Atlantic seaboard, from Florida as far south as Brazil. They are relatively ‘shallow’ fish and they prefer to be close to place where they can live safely and avoid the predators that lurk in open or deep water.

Black Margate (Melinda Riger / Grand Bahama Scuba)

Margates are not usually very large, mostly growing to between 18″ and 30″, although they can grow larger. Thanks to the awesomeness of Wiki and other reliable sources I can confidently report that “…the maximum recorded weight for this species is 5.8 kg (13 lb)“.

Black Margate (Melinda Riger / Grand Bahama Scuba)

MAY WE HAVE THE TRADITIONAL 10 FUN FACTS PLEASE?

  • Local names include burriquete (Sp) and zapatero or burros (Mex)
  • There are 10 margate species world wide, including 2 Pacific versions
  • Their heads slope down to a notably thick lipped mouth in which they have strong teeth
  • Margates have erectile spines, presumably for defence (I’ve not tested that)
  • They like to shelter in caves and crevices, on ledges, and in wrecks (see pics)
  • Margates are ‘solitary fish’ or hang out in small groups
  • They are night-feeders on a diet of crustaceans, mollusks, smaller fish & urchins
  • Sadly for them, they are valued by commercial fisheries using baited drift fishing…
  • …and also targeted by anglers during the spawning season when they shoal (?unfair)
  • … and also caught as aquarium fish, adding to stock depletion

Black Margate (Melinda Riger / Grand Bahama Scuba)

RELATED SPECIES

PORKFISH

Credits: all photos, Melinda Riger / Grand Bahama Scuba; research from magpie pickings and in particular the interesting mexicanfish.com

Black Margate (Melinda Riger / Grand Bahama Scuba)

BAHAMAS REEF FISH (50): TOBACCO BASSLET


Tobacco Basslet (Serranus tabacarius) Bahamas (Melinda Riger / GB Scuba)

BAHAMAS REEF FISH (50): TOBACCO BASSLET

Welcome to #50 in the Bahamas Reef Fish series. I chose this fish to honour the landmark before thinking about its features. Grumpy. Also, associated with a narcotic and dangerous drug. And a fish one probably wouldn’t bother to smoke (even if one could get it to light underwater). In the Bahamas you’ll find these little fish around the coral reefs where they play their part as reef denizens, which includes being prey to larger species. If one looks them up online, however, the overwhelming impression from the websites and images available is that they exist largely for the benefit of the aquarium industry.

Tobacco Basslet (Serranus tabacarius) Bahamas (Melinda Riger / GB Scuba)

Tobacco basslets (Serranus tabacarius) – more commonly just called tobacco fish or tobaccofish – are related to the HARLEQUIN BASS(LET), a species that was most unfairly included as #9 in my parallel WTF? series among all the seriously weird sea creatures that feature in that category. A wrong I must right one day.

Tobacco Basslet (Serranus tabacarius) Bahamas (Melinda Riger / GB Scuba)

Tobacco fish are considered to be hardy, unaggressive (except towards the tiny fishes and crustaceans they feed on) but apparently they need quite a large tank to hold them. The ocean might be suitably large for the purpose. Especially as it seems that in an aquarium there needs to be a cover on top: “these fish are expert jumpers…“, as one source puts it…

BESIDES THE BAHAMAS & AQUARIUMS WHERE ELSE DO THEY LIVE?

TOBACCO BASSLET RANGE MAP

APART FROM THE HIGH JUMP THING, ANY OTHER TRICKS?

Yes indeed. The Tobacco Basslet is hermaphroditic, like all other members of its genus.

DON’T LEAVE IT AT THAT… HOW DO THEY, YOU KNOW?

I didn’t want you to ask. All their FB pages say “It’s complicated“, but here’s a rough idea…

  • All individuals start life as simultaneous hermaphrodites (with sex organs of both sexes)
  • The largest fish lose their female functions and become active sperm-producing males
  • Each male leads a group of hermaphrodites and protects them from other males 
  • This gives them exclusive rights to the female parts of members of their ‘harem’
  • Sometimes hermies may use their male bits to join in & release sperm – ‘streaking’
  • There are rarer mating strategies… Oh heck, please look at the abstract of a scientific paper for details. I had to! And all because you, gentle reader, asked that question.

With some relief, here is very short video. It probably doesn’t accurately show how Tobacco fish might behave on a Bahamian reef. In captivity, from the look of it, they get pushed around by bigger fish. But maybe, if their co-residents are carefully selected, the bonus is that they don’t risk getting eaten.

OPTIONAL MUSICAL INTERLUDE

There are no songs ever that mention tobacco fish or tobacco basslets (though lots involve bass). And more oddly, apart from a couple of old blues songs the only truly mainstream song about tobacco by name (as opposed to content) is Tobacco Road, a song as frequently and thoroughly covered as an aquarium tank containing jumpy tobacco fish.

Rare photos from the actual sea captured by Melinda Riger of Grand Bahama Scuba; Science Direct plus magpie pickings; Captive Aquatic Ecosytems (video)

I didn’t enjoy this article about me very much. I am NOT grumpy.Tobacco Basslet (Serranus tabacarius) Bahamas (Melinda Riger / GB Scuba)

PURPLE VASE SPONGES: BAHAMAS REEF ORNAMENTS


Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

PURPLE VASE SPONGES: BAHAMAS REEF ORNAMENTS

The Purple Vase is an unmistakeable sponge, a colourful reef creature (for they are animals, of course) that stands even out amongst the bright corals that surround it. And like corals, sponges are vulnerable to all the usual threats (mainly human-generated).

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

Catch them while you can in the clear waters of the Bahamas while stocks last. I say this because as study after study concludes, the prospects of reef-mageddon get closer each year. When the corals die off, so in all probability will the sponges and anemones…

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

After such a depressing intro, let’s move on to take a positive look at the purple vase sponge. As with all sponges, once a newborn sponge is wafted by the current to a place on the reef, it takes root there throughout its life. There, these attractive sponges exist by filtering the water that surrounds them, separating out plankton to feed on. Static filter-feeders, if you will.

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

You’ll notice that in some of the photographs, the sponges have guests. These are BRITTLE STARS, and they are often found on – and indeed in – purple vases. This is a form of symbiotic relationship known as commensalism, in which one species benefits and the other is neither benefitted nor harmed. The brittle star gains a shelter and a safe base for feeding; the vase gets a harmless companion. Small fishes benefit from the vases in a similar way.

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

Besides the impact of damaging human interventions (which may be permanent), extreme weather events also affect reef life and the static inhabitants adversely. Storms and hurricanes can cause localised havoc, but the damage is not necessarily permanent. The reef can in time repopulate naturally and flourish again. Humans can even promote this recovery. The photograph above shows a purple vase sponge that was detached from the reef by Hurricane Matthew in October 2016. Melinda Riger in effect replanted it on the reef and it reattached itself and grew. In due course it even acquired its brittle star occupant. 

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

*JIMI AND ‘PURPLE VASE’ – A VOLUNTARY MUSICAL DIGRESSION

In an interview with NME Hendrix is reported to have said that Purple Haze “was about a dream I had that I was walking under the sea.” Originally the song was intended to be ‘Purple Vase’, and reflect the psychedelic experience of life on a coral reef. Realising he was getting bogged down by sub-aquatic imagery (he was a non-swimmer), he toked for a while and then ‘Purple Haze’ emerged almost fully formed. He was always far happier kissing the sky than wandering about under the waves. Most covers of the song are pale imitations of the original, but here’s a rather unusual take that succeeds by trying a different approach…

Credits: Melinda Riger / Grand Bahama Scuba for all great photos; magpie pickings for bits and pieces, with a shout-out to ‘Critter Squad’ for its informative site aimed at kids. And amateur grown-ups can benefit too… commensalism in humans; Friend ‘n’ Fellow audio

Purple Vase Sponge, Bahamas (Melinda Riger / G B Scuba)

FLORAL CORAL: REEF GARDENS IN THE BAHAMAS


Reef Corals, Bahamas (Melinda Riger / G B Scuba)

FLORAL CORAL: REEF GARDENS IN THE BAHAMAS

Like many of the blues musicians who covered Robert Johnson’s originals, we got ramblin’ on our minds. Specifically to ‘Delphi East’ in Ireland, thus stupidly exchanging 82F sunshine in southern UK for 46F rain in the Emerald Isle. Good for the fishing, if nothing else… So (always remembering that corals are actually creatures and not plants) here’s a bouquet of coral to be going on with until we next meet with wifi!

Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)Reef Corals, Bahamas (Melinda Riger / G B Scuba)

OPTIONAL MUSICAL RAMBLING

Robert Johnson’s output – a meagre 29 songs in all – formed the bedrock for later bluesmen and the blues / rock crossovers that followed. They mined Johnson’s talent and formed their own new material from it. Here’s the original – you’ve probably heard it or variations of it with different names, a thousand times – some good, some bad, most so-so. 

Entire coral pot pourri by Melinda Riger / Grand Bahama Scuba

BAHAMAS REEF FISH (44): PORKFISH


Porkfish (Grunt), Bahamas - Melinda Riger / Grand Bahama Scuba

BAHAMAS REEF FISH (44): PORKFISH

Behold the porkfish Anisotremus virginicus, the slightly unattractively named representative of the (arguably) even less attractively named grunt species. These small, bright-coloured reef dwellers are rarely more than 12 inches long. They are mainly nocturnal fish, feeding on small crustaceans, mollusks and so on. Juveniles have been observed acting as cleaners to larger species, feeding on parasites – an example of mutualism between species, in which both sides benefit from the arrangement.

Porkfish (Grunt), Bahamas - Melinda Riger / Grand Bahama Scuba

WHY IS A ‘PORKFISH’ A ‘GRUNT’

The terminology seems to be somewhat confused by local usages, but in general terms all porkfish are grunts; but not vice versa. Yet I notice that the term ‘porkfish’ is used to describe other types of grunt. A good rule of thumb is the the Atlantic Porkfish is the only grunt with two black vertical bars and yellow stripes… Note that grunts differ from their cousins the snappers by having a different dental arrangement – no canine teeth.

Porkfish (Grunt), Bahamas - Melinda Riger / Grand Bahama Scuba

AND WHY ‘GRUNT’ ANYWAY? DO THEY SOUND LIKE PIGS?

Well, perhaps a bit. All grunts, including porkfish, are capable of producing grunt-like sounds from some kind of grinding of their back teeth that is too technical to go into here**. The sound is associated with ‘situations of duress and danger’ – such as being caught and unhooked…

Porkfish (Grunt), Bahamas - Melinda Riger / Grand Bahama Scuba

DO YOU HAPPEN TO HAVE A RECORDING?

As it so happens I do. This is taken from a rather longer Youtube video in which a grunt was caught, unhooked and returned.You’ll hear a couple of grunts as the fish was unhooked, and some (perhaps understandable) hilarity on the boat. I guess you had to be there.

Porkfish are gregarious, and also mix with other speciesPorkfish (Grunt), Bahamas - Melinda Riger / Grand Bahama Scuba

ARE PORKFISH EDIBLE?

Like most if not all grunts, they are, with the proviso that there is some association with ciguatera. I’ve never knowingly eaten one myself, but I gather that “grits and grunts” is a popular culinary combo in some places. For those that might want to know more, a quick look at a couple of threads reveals the following:

  • They taste great, a bit like ham
  • Their white meat cooks very well
  • They taste better than black margates (another grunt species)
  • Eat them in enchilado or breaded fillets
  • ‘Big-ass head’ on them so not much if you filet
  • If you scale and cook whole you get a better yield on them
  • When fishing for supper, ‘shoot ’em up and hold off for the bigger ones’

Porkfish (Grunt) - Brian Gratwicke (wiki)

Credits: all great photos by Melinda Riger /  Grand Bahama Scuba, except the last by Brian Gratwicke (wiki); soundbite from Youtube video 2010 by peachyree; research from seaworld.org; britannica.com and the usual suspects…

** Subtle code for “I haven’t really understood it…”

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


Arrow Crab (Melinda Riger / Grand Bahama Scuba)

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

It’s been a while since the last in the WTF? series, which is dedicated to the wilder, less conventionally fish-shaped side of reef life – those creatures that you may come across, blink into your face-mask,  and silently mouth the words ‘What’s That Fish?’ (that’s what it looks like you are saying, anyway).

Arrow Crab (Adam Rees)

Let’s meet some Arrow Crabs Stenorhynchus seticornis, one of the very few creatures surely to have a triangular body plus a huge pointy nose (rostrum), supported on long skinny legs. To which add, they wear tiny blue gloves on their two front claws.

Arrow Crab (Melinda Riger / Grand Bahama Scuba)

These crabs are coral reef dwellers and mostly stay concealed during the day. Their body is protected by a carapace, and the rostrum has serrated edges like a tiny rasp or file. I haven’t found a definitive reason for this gadget, but I suspect it is more for probing than for piercing or fighting.

Arrow Crab (Melinda Riger / Grand Bahama Scuba)

There’s a considerable colour variation among these crabs, as these images show. The body may even have blue iridescent lines (#2, above). And those claws may be any of 50 shades of blue…

Arrow Crab (Melinda Riger / Grand Bahama Scuba)

Arrow crabs are most active at night. They eat feather-duster worms (illus.) and similar invertebrates such as bristle worms.

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

Arrow Crab Meal

Like certain types of shrimp, they also have a symbiotic relationship with anemones, whereby they make use of an anemone to benefit from the food it captures – and possibly for cover too. They are protected from anemone stings, whereas some of their predators are not.

This was the place where I was going to tell you about the arrow crab’s private life, but, well… “it’s complicated”. Briefly it is: male passes sperm-filled capsule to female; she uses it in some way whereby it fertilises her eggs; she then ‘broods’ the eggs in one of her ‘swimming legs’; the eggs hatch into larvae and swim off to eat plankton; each one then grows & moults, repeating the process until it has reached adult form. On balance, humans have arguably perfected a preferable method.

Arrow Crab (Nick Hobgood / Wiki)

Arrow Crabs are apparently popular aquarium creatures, although they sound to me rather a disagreeable challenge. They can move quickly on those long legs, and it seems as if they inclined to be aggressive to other inhabitants of the tank. As far as I can make out, it’s best not to put 2 of them together: they certainly won’t be doing the sperm capsule thing described earlier… 

Arrow Crab (Adam Rees)

Master of Disguise

Photo credits: Melinda Riger / G B Scuba (1, 3, 4, 5, 6); Adam Rees / Scuba Works (2, 8, 9); Nick Hopgood,Wiki (7); Chuck Elliot – video

Arrow Crab (Adam Rees)

CHRISTMAS TREE WORMS: SEASONAL SPIROBRANCHES


Christmas Tree Worm (Melinda Riger / Grand Bahama Scuba)

CHRISTMAS TREE WORMS: SEASONAL SPIROBRANCHES

music-notes-clip-art-png-musicDeck the Reefs with Worms Like Christmas Trees… Fal-La-La-etc-etc ” is a traditional Carol familiar to all. Well, most. Ok, some, then. Oh right – maybe with different words? Anyway, now is the perfect time to take another look at these remarkable subsurface symbols of seasonal good cheer (nb they are animals not plants).

christmas-tree-worm-melinda-riger-g-b-scuba

10 CHRISTMAS TREE WORM FACTS TO PONDER

  • The 2 colourful spirals are not the worm, but complex structures for feeding & respiration
  • The spirals act as specialised mouth extensions for ‘filter-feeding’
  • Prey is trapped by the feathery tentacles & guided by cilia (microscopic hairs) to the mouth
  • The tentacle things are radioles and act as gills for breathing as well as prey traps
  • It is not believed that prey slide down the spiral to their doom, like on a helter-skelter

Christmas Tree Worm (Neil Hobgood Wiki)Christmas Tree Worm (Melinda Riger / Grand Bahama Scuba)

  • The actual worm lives in a sort of segmented tube, with extremely limited mobility skills
  • It contains digestive, circulatory & nervous systems – and a brain in the middle of it all
  • The worm also has a tiny drainage tube (I think I have this right) for excretion etc
  • They embed themselves into heads of coral such as brain coral. And stay there
  • And yes, the Christmas trees are retractable… (see below for some action)

spirobranchus_giganteus_orange_christmas_tree_worm-nick-hobgood-wiki

HOW DO THE WORMS… YOU KNOW…  ERM… REPRODUCE?

This is a delicate area. They don’t tend to talk about it much, but as far as I can make out they eject gametes from their what-I-said-above. There are mummy and daddy worms, and their respective gametes (eggs and spermatozoa) drift in the current and presumably into each other to complete the union. The fertilised eggs develop into larvae, which settle onto coral and burrow into it, build their protective tubes and the process begins again.

christmas_tree_worm-nick-hobgood-wiki

YOU DON’T REALLY UNDERSTAND THESE CREATURES, DO YOU?

I won’t lie. I found it hard to work out how the CTWs function in practice. There are plenty of resources showing them in their full glory, but that only takes one so far. Then I came across a short video that shows it all brilliantly simply (except for the reproduction part).

The worms, in their coral burrows, hoist their pairs of ‘trees’. You can easily see small particles – possibly zooplankton – drifting in the water, and the radioles swaying to catch potential food. Suddenly it all makes sense (except the repro bit – I haven’t found footage of that).  Next: the New Year Worm (there is no Easter worm).

A WHOLE FESTIVAL OF CHRISTMAS TREE WORMSChristmas Tree Worms (Neil Hobgood Wiki)

Credits: Melinda Riger (G B Scuba); Nick Hobgood; Betty Wills; Video by ‘Super Sea Monkey’;Reef Collage by RH; MarineBio; Wikibits & Magpie Pickings

Happy Christmas to all those who put up with RH with such fortitude
blue_christmas_tree_worm-betty-wills-wiki

‘RAISE AWARENESS’: SPOTTED EAGLE RAYS


Spotted Eagle Rays, Abaco, Bahamas (Gabrielle Manni)

Spotted Eagle Rays – Abaco, Bahamas

‘RAISE AWARENESS’: SPOTTED EAGLE RAYS

Mention of rays may conjure up thoughts of the familiar southern stingrays that populate the bright shallows and colourful reefs of the Bahamas. But there are other ray species out there gracefully patrolling the coral reefs – and one of these species is the spotted eagle ray (Aetobatus narinari).

Spotted Eagle Rays, Abaco, Bahamas (Catherine / Tara Pyfrom)

These fish (for that is what they are) are not uncommon. In fact they are found in tropical oceans worldwide (though there is a taxonomic distinction between the Atlantic version and the Pacific / Indo-Pacific ones). Note the concentration in the Caribbean sea.

Spotted Eagle Rays, Grand Bahama, Bahamas (Melinda Riger / GB Scuba)

Spotted eagle rays obviously have spots, but they are not notably eagle-like to look at. In fact, their snouts resemble a duck’s bill, and in some place they are less glamorously known as the duckbill ray. The ‘eagle’ part relates to the way in which they use their wings and appear to be soaring as they glide effortlessly through the water (see videos below).

Spotted Eagle Rays (Lazlo-photos Wiki)

Despite their global presence, these rays are categorised as ‘near-threatened’ on the IUCN Red List. Aside from vulnerability to predators including many types of shark, the rays may be caught as bycatch. In some areas they suffer entanglement in shark nets. And unsurprisingly there is a trade for them for large commercial aquariums. For the Atlantic species, Florida has taken a lead by banning fishing for, landing, buying or trading in spotted eagle rays. 

Spotted Eagle Rays, Abaco, Bahamas (Gabrielle Manni)

10 ESSENTIAL FACTS ABOUT SPOTTED EAGLE RAYS

  • They have 2 – 6 venomous barbed spines at the base of the tail
  • Adults are among the largest rays, with a 10 ft wingspan
  • They can leap clear of the water, and may do this more than once at a time
  • Occasionally they land in boats, to the consternation of all concerned
  • Their main diet is small fish and crustaceans, & sometimes octopuses
  • Their broad snouts are used to dig food out of the seabed as they forage
  • The rays are basically shy but may be curious of divers & snorkellers
  • They suffer from parasites, both externally and in their gills
  • Ray sex is quite physical, yet actual mating is brief (up to 90 secs…)
  • The female hatches her eggs internally, then her ‘pups’ are born live a year later

SPOTTED EAGLE RAY PUP

                          

Spotted Eagle Ray (John Norton Wiki)

 VIDEO SHOWCASE
These 3 short videos demonstrate the grace and beauty of spotted eagle rays as they glide elegantly around the reefs. The first (50s) was taken off Grand Bahama by Fred Riger (Melinda’s husband, for those who follow the underwater forays hereabouts); then one by Stephen Dickey (2:12) ; and finally one from Wildscreen Arkive (2:00).

WEIRD CREATURE CORNER

I have a lot of time for these cards produced by ‘Weird ‘n’ Wild Creatures’. In their unique style they are simple, educative and often give information nuggets not found elsewhere. The link is to their 4th series, Monsters of the Deep.

 

Photo credits: Gabrielle Manni (1), (5); Catherine & Tara Pyfrom (2); Melinda Riger / Grand Bahama Scuba (3); Lazlo-photos Wiki (4); Wiki (baby ray thumbnails); John Norton Wiki (6); Jacob Robertson Wiki (7); Weird ‘n’ Wild Creatures – card images. Videos as credited in text.

Spotted Eagle Ray, TCI (Jacob Robertson, Wiki)

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN


Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN

Hawksbills on their own, nosing around the colourful coral reefs of the Bahamas, are a beautiful sight. I don’t want to overdo the religious tendency of the title, but they are indeed wonderful to behold. Add FRENCH ANGELFISH and a QUEEN ANGELFISH and it’s as close to perfection as a reef scene gets. Click on the links above for more pictures and details about the two angelfish species seen here with the turtle. As ever, Melinda Riger was ready with her camera to capture these great images.

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

This astonishing photo was of course achieved by carefully balancing a GoPro on the turtle’s back, wrapping duct tape around it, and pressing ‘go’ (camera and turtle simultaneously). **

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

** This is not true. It’s just a cleverly shot turtle’s-eye view as it forages on the reef

This short video shot by Melinda’s husband Fred of a turtle ‘loving’ the camera is one of those wildlife events that cannot be predicted… but when it happens, it’s frankly a bit of a scoop.

OPTIONAL MUSICAL DIGRESSION

As I was writing this, an earworm started up and grew insidiously in both ears and then inside my head… the dread words “Elenore, gee I think you’re swell”. Followed by “so happy together…”. And then “she’d rather be with me…” Yes, I’ve now got TURTLES in my head, the (?long-and-hitherto-forgotten) band from the second half of the 60’s, with their cheery anodyne soppy-poppy love songs. And dammit, they’ve stuck… Here’s a reminder for those whose memory I have jogged. For anyone under, say, 75, step away from this area. Nothing to hear here.

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

Credits: Grand Bahama Scuba: all photos – Melinda Riger & video – Fred Riger; Turtle music – someone else’s music collection, not mine, honestly… (oh dear another lie I am afraid – cred gone)

ONE GOOD INTERN DESERVES ANOTHER (Part 1)


Coral reef research, Australia (Oscar Ward)

ONE GOOD INTERN DESERVES ANOTHER (Part 1)

Four years ago a young English friend of ours, Oscar Ward, was lucky enough to be offered an internship with the Bahamas Marine Mammal Research Organisation (BMMRO). At the time, he was post-school, and waiting to start a degree course in marine biology at university. He had no practical experience at all, so he had to progress from the menial tasks (scraping barnacles off the bottom of the research boat) to the more adventurous (whale poop-scooping) to the scholarly (collection and analysis of samples and data, including audio file matching of whale calls for identification). The need for hard work, concentration and accuracy were made clear from the outset… and as you will see, Oscar’s short internship has stood him in very good stead during his university course.

Oscar weekending at Gilpin Point – self-sufficientBMMRO Internship - weekend off (Oscar Ward)

From a promising start on Abaco, and with 2 year’s study behind him, Oscar is currently spending the 3rd year of his 4-year course in Australia, working with The Australian Institute of Marine Science. He has been involved in a number of complex projects focussed on corals and reef life – as we all know, a matter of huge concern – and the projections for the future of the reef systems in a time of warming seas and raised acid levels. Oscar also assists PhD students, for example examining the damaging effects of parasitic worms on coral; and the effect of changing light conditions on corals.

Nurse Sharks, Great Barrier Reef (Oscar Ward)

Much of Oscar’s time has been spent doing fieldwork. Often he is at sea, monitoring and collecting samples in the Southern Great Barrier Reef, diving two or three times a day. This work is often carried out in restricted or preservation zones, and with ever-present manta rays, sharks and sea turtles around him.

Manta Ray, Great Barrier Reef (Oscar Ward)

Right now Oscar is involved with the investigations into the recent bleaching events, work that is at the forefront of serious concern for the GBR and far beyond. I have recently corresponded with him – he has definitely not forgotten that his grounding for the fieldwork and studies that he is engaged in – and very likely his career – came from his time on Abaco and the lessons he learned during his time with the BMMRO at Sandy Point.  (In part 2: another good intern, currently at Sandy Point)

Coral reef research, Australia (Oscar Ward)

All photos: Oscar Ward (the header image is taken from a research vessel – no idea how, maybe a drone with fish-eye lens?)

CHRISTMAS TREE WORMS: FABULOUSLY FESTIVE


christmas-tree-worms-adam-rees-scuba-works-copy

CHRISTMAS TREE WORMS: FABULOUSLY FESTIVE

music-notes-clip-art-png-music“Deck the Reefs with Worms Like Christmas Trees… Fal-La-La-etc-etc ” is a traditional Carol familiar to all. Well, most. Ok, some, then. Oh right – maybe with different words. Anyway, now is as good time as any to take a look at these remarkable plants creatures and subsurface symbols of good cheer.

christmas-tree-worm-melinda-riger-g-b-scuba

10 CHRISTMAS TREE WORM FACTS TO PONDER

  • The 2 colourful spirals are not the worm, but complex structures for feeding & respiration
  • The spirals act as specialised mouth extensions for ‘filter-feeding’
  • Prey is trapped by the feathery tentacles & guided by cilia (microscopic hairs) to the mouth
  • The tentacle things are radioles and act as gills for breathing as well as prey traps
  • It is not believed that prey slide down the spiral to their doom, like on a helter-skelter

christmas-tree-worms-melinda-riger-g-b-scuba

  • The actual worm lives in a sort of segmented tube, with extremely limited mobility skills
  • It contains digestive, circulatory & nervous systems – and a brain in the middle of it all
  • The worm also has a tiny drainage tube (I think I have this right) for excretion etc
  • They embed themselves into heads of coral such as brain coral. And stay there
  • And yes, the Christmas trees are retractable…

spirobranchus_giganteus_orange_christmas_tree_worm-nick-hobgood-wiki

HOW DO THE WORMS… YOU KNOW…  ER… REPRODUCE?

This is a delicate area. They don’t tend to talk about it much, but as far as I can make out they eject gametes from their what-I-said-above. There are mummy and daddy CTWs, and their respective gametes (eggs and spermatozoa) drift in the current and presumably into each other to complete the union. The fertilised eggs develop into larvae, which settle onto coral and burrow into it, build their protective tubes and the process begins again.

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LOOK, YOU DON’T REALLY UNDERSTAND THESE CREATURES, DO YOU?

I won’t lie. I found it hard to work out how the CTWs function in practice. There are plenty of resources showing them in their full glory, but that only takes one so far. Then I came across a short video that shows it all brilliantly simply (except for the reproduction part). So maybe I should have just posted this first and saved you (and me) some trouble…

The worm, invisible in its coral burrow, hoists its pair of trees. You can easily see small particles – possibly zooplankton – drifting in the water, and the radioles swaying to catch potential food. Bingo. It all makes sense! Next: the New Year Worm

Credits: Melinda Riger (G B Scuba); Adam Rees (Scuba Works); Nick Hobgood; Betty Wills; Absolutely Wild Visuals; MarineBio; Wikibits & Magpie Pickings

blue_christmas_tree_worm-betty-wills-wiki

FLORAL CORAL: BEAUTIFUL BAHAMIAN REEF LIFE


coral-soft-corals-melinda-riger-g-b-scuba

FLORAL CORAL: BEAUTIFUL BAHAMIAN REEF LIFE

This post needs no commentary from me, nor my larky intrusions. These wonderful images from Melinda Riger speak for themselves. You’ll see a wide variety of soft and hard corals in the images below (prize** for the full list). If these superb photos don’t want to make you want to grab a snorkel, mask and flippers, then… well, that would be a very great shame.

coral-melinda-riger-g-b-scubacoral-melinda-riger-gb-scubacoral-reef-2-melinda-riger-g-b-scubafire-coral-melinda-riger-gb-scubapillar-coral-melinda-riger-gb-scubablushing-star-coralpurple-sea-fan-melinda-riger-g-b-scubapurple-sea-fan-melinda-riger-g-b-scuba-copy

**the prize is the usual legendary bottle of Kalik. Or do I mean mythical?

All wonderful photos by Melinda Riger, Grand Bahama Scuba. All corals also available in a wide range of colours in Abaco waters. See them there on the third largest barrier reef in the world (and in rather better nick that the greatest, by all accounts).

SILVERSIDES: BAHAMAS REEF FISH (32)


silversides-school-melinda-riger-g-b-scuba

SILVERSIDES: BAHAMAS REEF FISH (32)

I have no idea if there is a collective noun for a large group of silversides. ‘Frenzy’ would cover it, but that is reminiscent of ‘feeding freezing’ which has a specialist meaning – and anyway, silversides are crazy even when they aren’t feeding. 24/7/12/365 as far as I can make out. I think ‘a panic of silversides’ might be the answer. They are just… all over the place at high speed. Sometimes swirling around pointlessly, other times moving in unison and suddenly all changing direction simultaneously, like a single creature made of tiny shards of silver.

silversides-school-melinda-riger-g-b-scuba-copyfish-frenzy-melinda-riger-gbs

There are quite a few silverside species around the world. The ones in the Bahamas are Atlantic silversides (Menidia menidia), also known in the north east of the United States as ‘spearing’. They seem to exist for two purposes. The main one is to be breakfast, lunch or dinner for larger fish, sea birds and shore birds. The other is for their usefulness in scientific research because of their sensitivity to environmental changes. 

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In one sense they are easy prey for predators. A determined fish will always manage a snack by swimming into the middle of a panic and (probably) simply by opening its mouth wide. On the other hand, their sheer numbers coupled with the speed and randomness of movement mean that a single may find a degree of safety in numbers. It’s hard for a predator to target any individual fish in the general melee and confusion. Silversides also favour seagrass beds, which give some shelter and protection – and a reasonably safe place to spawn. Or, as some of these photos show, they will hang around wrecks or squeeze into rocky spaces in the reef.

silversides-melinda-riger-g-b-scuba-copysilversides-melinda-riger-g-b-scuba

A panic of silversides apparently pouring like a waterfall down through a gap in the reefsilversides-waterfall-abaco-kay-politano

WHAT DOES A STATIONARY ATLANTIC SILVERSIDE LOOK LIKE?

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Some time ago we used to go to the reef at Fowl Cay Marine Preserve with Kay Politano, and I would snorkel with a small and very basic lo-res underwater camera. I was hampered by being a disgracefully feeble swimmer; by not having snorkelled for a length of time calculable in decades; and by being a complete novice at underwater photography.  Despite these not inconsiderable disadvantages I managed to cobble together a few short movies on my computer (I was new to that too). Here’s one that nearly works, in that it gives an idea of what happens if you ‘swim with silversides’. I know you scuba guys all swim with sharks, but cut me some slack here please…

Photo Credits: Main photos Melinda Riger of Grand Bahama Scuba; Silverside Waterfall by Kay Politano; motionless silversides by FISHBASE.ORGMusic: Goldon Giltrap, ‘Fast Approaching’

MAKE FRIENDS WITH ANEMONE (2): SPECTACULAR REEF LIFE


Corkscrew Anenome = Peterson Cleaner Shrimps ©Melinda Riger @G B Scuba copy

Corkscrew Anemone with Peterson Cleaner Shrimps

MAKE FRIENDS WITH ANEMONE (2):  SPECTACULAR REEF LIFE

Going snorkelling? Planning a scuba day on the reef? You’ll see wonderful fish and amazing coral for sure. But sometimes the beauty of other life on the reef can be overlooked. Check out the anemone in the header image, with the camouflaged cleaner shrimps playing around it. You wouldn’t want to miss a sight like that. The many and varied forms and colours of anemone on the reefs of the Bahamas make up a vital component of a spectacular underwater world.

Giant Anenome ©Melinda Riger @ G B Scuba copyGiant Anemone ©Melinda Riger @ G B Scuba copy 4Anemone Melinda Riger @ G B ScubaAnemone on Rope ©Melinda Riger @ G B ScubaAnemone ©Melinda Riger @ Grand Bahama ScubaAnemone (Giant) ©Melinda Riger @GBS copyAnemone ©Melinda Riger @ GB Scuba

ADDED NOV 2016 Capt. Rick Guest adds this interesting material (& thanks for correcting my erroneous reference to anemones as ‘plants’. My bad. They are of course animals!):

“Anemones are living animals of the invertebrate type. Basically living corals without skeletons. All have stinging cells of several varieties to sting or entangle their prey such as small fish, or various invertebrates. A few can even, painfully, penetrate human dermal layers. Most host varieties of cleaner shrimps,and snapping shrimps that can stun their own prey. Some Dromidia crabs even pull some species of anemone off the reef, and attach them to their carapace (their back) apparently for camouflage, and perhaps protection”.

All photos: Melinda Riger of Grand Bahama Scuba, with thanks

BLUE CHROMIS: BAHAMAS REEF FISH (29)


Blue Chromis & Coral ©Melinda Riger @ GB Scuba

BLUE CHROMIS: BAHAMAS REEF FISH (29)

The little blue chromis Chromis cyanea will be instantly familiar to any snorkeler or scuba diver on the coral reefs of the Bahamas. These ever-present small fish – 6 inches long at most – are remarkable for their iridescent deep blue colour that flashes as they dart in and out of the coral and anemones of the reef.

Blue Chromis ©Melinda Riger @ G B Scuba

Although at first sight  this chromis species – one of many – looks blue all over, adults have a black dorsal stripe and black edging to their fins. They make colourful additions to aquariums, though to my mind they look far more attractive nosing about the reefs foraging for the zooplankton upon which they feed (see header image for details…)

Blue Chromis ©Melinda Riger @ GB Scuba

The blue chromis was the second fish species I encountered on my first ever reef dive, at Fowl Cay Marine Preserve with Kay Politano. The first fish was the endearingly inquisitive sergeant major with its smart black and yellow stripes which came right up to my googles to eyeball me. I loved that, even though my pitiful swimming technique meant that I had plenty of other distractions, not least remembering to breathe. Air, that is, rather than water.

Blue Chromis ©Melinda Riger @ GB Scuba

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SO JUST HOW BIG ARE THESE FISH, COMPARED, SAY, TO A BLUE TANG?

Blue Tang with blue chromis in its wakeBlue Tang with Blue Chromis © Melinda Riger @GB Scuba copy

All photos Melinda Riger of Grand Bahama Scube, except the penultimate by James St John, taken in San Salvador

 

WTF? (WHAT’S THAT FISH) (6): THE SAND DIVER


Sand Divers Bahamas ©Melinda Riger @ G B Scuba

WTF? (WHAT’S THAT FISH) (6): THE SAND DIVER

Time for another in the WTF? series, featuring weird (begging their pardons) or not very fish-like fish. The Sand Diver Synodus intermedius is a type of lizardfish found in subtropical waters and often around coral reefs. They can grow up to about 18 inches long and a prime specimen might weigh a couple of pounds. The markings are quite variable but one common characteristic seems to be a tendency to look somewhat down in the mouth; and to possess jaws full of tiny sharp teeth.

Sand Diver - ©Melinda Riger @ GB Scuba

Sand divers have two rows of teeth on their upper jaw and three rows on their lower jaw. Not content with that, they also have rows of teeth on the palate and tongue. Were they 50 times the size, they would be truly awesome.

Sand Diver ©Melinda Riger @ G B Scuba

The rather primitive appearance of the sand diver is explicable from fossils, which show that their forbears  were active in the Jurassic / Cretacean periods.

Sand Diver ©Melinda Riger @ GB Scuba

HOW DO THEY GET THEIR NAME?

Sand divers often bury themselves in the sand with only their head showing. They are so-called ‘ambush predators’, and burial is one method they use. Another is simply to lie on the sandy bottom, or on reef surfaces and wait for passing prey. Their colouring provides very good camouflage.Sand Diver Fish

WHAT’S ON A SAND DIVER MENU?

A good mix of small reef fishes. Bar jacks, blue chromis, wrasses, fairy basslets, small grunts and so forth. At their own level they are quite fearsome predators.

Sand Diver © Melinda Riger @ Grand Bahama Scuba

ARE THEY ON THE HUMAN MENU?

Well, I knew someone would ask that, so I carried out a search. The answer seems to be no. I have found nothing to suggest that they are edible, or that anyone has tried (or if they have, survived to tell the tale). Incidentally, the best way to find out if something is edible by humans is to search for a recipe. There are no sand diver recipes.

STOP PRESS Jason Knight has drawn my attention to a comment in WhatsThatFish.com (no relation) by one ‘Jenny’, who commends Sand Divers as food (“they cook up just as good as hogfish!”). So yes, they are edible and there is one recipe… 

Sand Diver ©Fred Riger @ G B Scuba

All photos: Melinda Riger of Grand Bahama Scuba

BAHAMAS REEF CORAL: A COLOURFUL GALLERY


Orange Cup Coral ©Melinda Riger @ G B Scuba copy

BAHAMAS REEF CORAL:  A COLOURFUL GALLERY

The reefs of the northern Bahamas, as elsewhere in the world, are affected by two significant factors: climate change and pollution. Stepping carefully over the sharp pointy rocks of controversy, I’ve avoided the term ‘global warming’ and any associated implication that humans (oh, and methane from cows) are largely to blame for the first factor; but on any view, ocean pollution is the responsibility of mankind (and not even the cows). 

That said, an exploration of the reefs of Abaco or Grand Bahama will reveal not just the astounding variety of mobile marine life but also the plentiful and colourful static marine life – for example the beautiful and Christmassy orange cup coral in the header image. Here are some more corals from the reefs, with a mix of sponges added in. 

Giant Star Coral & Rope Sponge ©Melinda Riger @ GB Scuba copyCorals ©Melinda Riger @ G B Scuba copy 2Corals ©Melinda Riger @ GB Scuba copySea Fans & other corals ©Melinda Riger @ Grand Bahama Scuba copy

This rather intriguing photo shows a hermit crab’s conch home that presumably the occupant grew out of and left behind in the delicate coral branches as it went search of a more spacious shell dwelling.Coral & conch ex crab home 1380179_645156602172399_300806994_n copy

Credits: All these wonderful photos are by Melinda Riger of Grand Bahama Scuba; tendentious reef health observations are mine own…

MAKE FRIENDS WITH ANEMONE: BAHAMAS REEF LIFE


Anemone (Giant) ©Melinda Riger @GBS copy

MAKE FRIENDS WITH ANEMONE: BAHAMAS REEF LIFE

The giant anemone is found in the shallow reefs and lagoons of the Caribbean and western Atlantic. These are, of course, animals and not plants, with many tentacles that surround their mouth. They attach themselves to rock or in rock crevices, mooring themselves securely against the swell of the waves.  

Giant anemone with ‘Speckles’, a spotted moray eelGiant Anemone & Speckles ©Melinda Riger @ G B Scuba copy

ARE THEY USEFUL?

One important feature of a healthy anemone population is the shelter they give to certain small fish and cleaner shrimp species. They act as bases for FISH CLEANING activities, a vital role in the undersea community.

Giant Anemone ©Melinda Riger @ G B Scuba copy

HOW DO THEY HAVE… ERM… SEX?

The sex lives of anemones seems particularly complicated (as they would doubtless think about humans). Cutting to the chase, reproduction involves the synchronous spawning of eggs and sperm, with fertilisation occurring in the surrounding water. The fertilised eggs become larval and spread in the water column, which increases their chances of survival. They settle on the BENTHOS, where they develop a “pedal leg” (rather in the manner of a gastropod) which in due course they will use to move from A to… A plus a very short distance.

Giant Anemone ©Melinda Riger @ G B Scuba copy 4

These anemones come in many colours. The tentacles often have tips of various hues, and are the only free-floating part of the animal. The body is safely attached to the rock. 

The giant anemone has primitive defensive mechanisms. It needs them, because it crawls so slowly that successful escape by moving is unlikely. Instead they reduce their size by drawing their tentacles into, or as close as possible to, their gastric cavity. They make room for this by forcing most of the water out. This reduces their overall size and of course removes – or at least diminishes – the ”50 colourful tentacles waving around” predator-magnet problem. But also…
Giant Anemone ©Melinda Riger @ G B Scuba copy 7
…they have a trump card. The tips of the giant anemones’ tentacles are packed with cells that contain a toxin. When stimulated, the cells (‘nemocysts’) “explode out of the capsule, impaling the attacker”. The toxin is then discharged, causing extreme pain and paralysis. How cool is that? It’s the superpower we’d all like to have! Or is that just me?
This is also how an anemone feeds, by quickly paralyzing its prey with the ‘toxic tentacles of doom’. The prey is moved to the mouth and swallowed whole…
Giant Anemone ©Melinda Riger @ G B Scuba copy 6
Credits: Melinda Riger of Grand Bahama Scuba, with thanks as always

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

Peacock Flounder on a plate – Kim Rody Art983829_10154948988290716_6633206689277673329_n

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