IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?


Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?

The waters of Abaco teem with myriads of fish that depend on the coral reefs for shelter and safety, for breeding, for growing up in, and for nourishment. Sea fans (or gorgonians, to use the technical name) are animals too. They may look like plants and stay rooted to the spot, but like anemones these ‘soft corals’ are creatures of the reef and essential indicators of its health.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

At the moment it can still be said that the static (‘sessile’) members of the Abaco reef community are relatively unscathed by the impact of (and I don’t want to get into any arguments here) whatever causes mass bleaching and the death of reefs elsewhere in the world.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)  Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

The purple sea fan Gorgonia ventalina (classified by Linnaeus in 1785) is one of the most common species of sea fan, and a spectacular one at that. The main branches are linked by a lattice of smaller branches. Below the ‘skin’ is a skeleton made of calcite compounded with a form of collagen. 

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Sea fans are filter-feeders, and have polyps with eight tiny tentacles that catch plankton as it drifts past. They develop so that their orientation is across the prevailing current. This maximises the water passing by and consequently the supply of food as the fans gently wave in the flow.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)  Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Gorgonians have a chemical defense mechanism that protects against potential troublemakers. The main effect is to make themselves unpleasant to nibble or uproot.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One species impervious to this deterrent is the fascinating FLAMINGO TONGUE SNAIL (more of which quite soon). Other ‘safe’ species include the fireworm and BUTTERFLYFISHES.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One benefit of sea fans to mankind is that their defensive chemicals have been discovered to provide the basis for drug research and development. It’s tempting to say that by way of gratitude, we pollute the waters they need for their very existence. So, consider it said…

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)    Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

All the photos featured are by courtesy of Capt. Keith and Melinda Rogers of the well-known local scuba dive and snorkel centre DIVE ABACO, located in central Marsh Harbour. As prime enablers of reef exploration in Abaco waters, it can truly be said that they too have plenty of fans.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Credits: Keith and Melinda Rogers; Dive Abaco @DiveAbaco, Marsh Harbour, The Bahamas ** The answer to the questions in the Title is… it’s both!

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

PILOT WHALES: “DIVIDED BY A COMMON SEA”


Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

PILOT WHALES: “DIVIDED BY A COMMON SEA”

You know the thing about Britain and the US being ‘two Nations divided by a common language’? Among the many august people credited with first coming up with this remark, the leading contenders are Oscar Wilde, George Bernard Shaw and Winston Churchill. Generally, Wilde seems to be considered the winning author**. Whichever, the saying is intended to be lightly and amusingly rude, probably to both nations.

Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

Well, pilot whales are in a similar position. They are found on both sides of the Atlantic (and many other places of course). As acoustic analysis of the sounds made by marine mammals becomes increasingly sophisticated, the evidence suggests that a pilot whale in The Canary Islands saying “Hey guys, meal approaching 11.00 o’clock, moving right, 30 feet” will use different sounds from its counterpart in the Bahamas.

A pilot whale with a recent injury to its jaw. Chief suspect: a COOKIECUTTER SHARK?Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

Short-finned pilot whales (Globicephala macrorynchus) are also known as blackfish or potheads (though some may reserve this last term for – ahem – higher species). As with MELON-HEADED WHALES, they are in fact a species of large dolphin. They can grow to nearly 20′ long and weigh accordingly.

Pilot whales live in large pods of 50 or more. These are so-called ‘matrilineal’ groups, meaning that they consist of 2 or even 3 generations of related females. When the sea is calm, they sometimes adopt a behaviour known as ‘logging’, in which they will spend a long time – maybe hours – lying on the surface in tight groups.

Pilot Whales, Abaco Bahamas (BMMRO / Rolling Harbour)

In The Bahamas, pilot whales are seen year-round but are more common during the spring and summer months. Some are resident, but Bahama pilot whales appear to have large ranging patterns. Pilot whales tagged in The Bahamas have travelled as far north as North Carolina suggesting they are part of a population located in the US southeast .

HOW DO RESEARCHERS RECOGNISE EACH ANIMAL?

The first place to look is the dorsal fin. There are (at least) two reasons for this. First, it’s the part of the dolphin / whale that is most visible through binoculars; secondly, it is the part that tends to acquire nicks, ragged edges, and scar patterns that are unique to that animal. When a new cetacean is sighted, it is logged and assigned an ID. This will usually be kept simple and scientific: “look, there’s AL16 again” and so on; how unlike birds, where banders assign names such as Felicia Fancybottom, Bahama Mama and Harry Potter.  

If you look at #2 above, notice the distinctive hooked dorsal fin of the right-hand pilot of the trio. An easy ID for future sightings. And see below for nicks and scarring.

Pilot Whales - dorsal fin ID, Abaco Bahamas (BMMRO / Rolling Harbour)

MEANWHILE, 3643 MILES EAST ACROSS THE ATLANTIC

Last Autumn my niece and her family went to La Gomera, a small volcanic island in the Canaries. They all went on a whale / dolphin watching trip and were delighted to encounter a group of pilot whales. My great nephew, not yet a teenager, had an iphone with him and in the circumstances of standing on a moving platform photographing creatures swimming fast through the water, he did a very good job. A couple of them even have a bonus shearwater.

Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN) Pilot Whales, La Gomera, Canary Isles (Rolling Harbour / YN)

The west and east Atlantic pilot whales shown here are almost exactly on the same latitude

I’m not particularly bothered by my lack of photographic eptitude, but even I feel that my own shot of a pilot whale  in the Sea of Abaco rates high in the list of epic fails

The identity of the photographer is protected under the Official Secrets Act 1989

** ‘We have really everything in common with America nowadays except, of course, language’ Oscar Wilde The Canterville Ghost (1887)

Photo Credits: 1 – 5, BMMRO / Rolling Harbour; 6 – 10, my naturalist nephew Yarin; 11, name withheld by order of the management; 12, Marina Nolte / Wiki. General thanks: Diane, Charlotte, BMMRO

Pilot Whale (Marina Nolte / Wiki)

WTF? (WHAT’S THAT FISH?) 17: YELLOWHEAD JAWFISH


Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

WTF? (WHAT’S THAT FISH?) 17: YELLOWHEAD JAWFISH

It’s been a little time since I added to the WTF? series, in which some of the more outlandish reef denizens come under close scrutiny. Jawfishes (Opistognathidae) come into this category, not least because of their interesting ways with their eggs. Also, they tend to stick upright out of the substrate, which is not especially fishy behaviour.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

More than 50 species of jawfish are found around the world. In the Bahamas, you are most likely to encounter the Yellowhead (or Yellow-headed) variety. And if you think they look slightly… primitive, that’s because they are. In fact, their forebears (forefishes?) originated in prehistoric times, specifically the Miocene era (a lot of million years ago, I didn’t count exactly).

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

These rather extraordinary little fish superficially resemble certain types of BLENNY. Their modus operandi is to burrow down into sandy, gravelly or other loose substrate. They do so by cramming their mouths with sand and spitting it out to one side. By this means they form a tunnel of sorts in which they can live, and from which they can emerge, or half-emerge and take a look around them. As they do so, they hoover up passing food, mostly plankton and suchlike.

Yellowhead Jawfish (Virginia Cooper / Grand Bahama Scuba)

If something looks threatening while they are feeding or having a look around, they can simply duck down into their burrow for safety. They guard their patch against rivals, and behave ‘territorially’ in the jawfish community. One method is to ingest and and then eject sand or gravel at a would-be intruder.

Yellowhead Jawfish (Michael Wolf Wiki))

YES, BUT WHERE IS THE REAL ‘WTF?’ FACTOR HERE?

Good question. With a good and original answer. These little creatures are so-called MOUTHBROODERS‘, meaning that they carry their eggs in their mouths. Depending on the species, females, males or even both parents (don’t try this at home) will do this at or after fertilisation. In effect the eggs are safely incubated until they hatch as fry. Then they are on their own.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

ARE THERE ANY DRAWBACKS TO THIS UNUSUAL GESTATION METHOD?

Apart from accidentally swallowing the occasional potential junior, the eggs need aeration from time to time. This is achieved by expelling the eggs from the mouth, and quickly sucking them back in again. Try this very short video to see this rather improbable behaviour in action. It’s only 8 seconds blink and you’ll miss the action. The eggs hatch into fry in 8 – 10 days, after which both parents can relax. Until the next time.

Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)
Photo Credits: all images from Melinda Riger / Grand Bahama Scuba except (4) Virginia Cooper / GBS; (5) Michael Wolf / Wikimedia; video, Alan Keller. Research: magpie picking, not excluding yet not limited to Wiki…
Yellowhead Jawfish (Melinda Riger / Grand Bahama Scuba)

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)

FORAYS WITH MORAYS (6): WELL SPOTTED…


Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

FORAYS WITH MORAYS (6): WELL SPOTTED…

I was always taught ‘keep your mind open and your mouth closed’. Bad advice. Such bad advice. The worst. So many reasons to be exactly the opposite in these troubled times…

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

Spotted Moray eels Gymnothorax moringa, however, seem to have their own rules to live by. They appear to be open-minded and fairly sensible creatures around the reef. They tend to keep themselves to themselves, hanging out unassumingly in holes and crevices in the coral.

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

They do tend to stick their necks out a bit, but unless provoked (see below) they seem to be reasonably amiable (except maybe to the small fish and crustaceans that make up their diet).

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

They do keep their mouths open a lot, though. And as you can see, they have sharp-looking teeth that you mightn’t want too near to you. I say that because their bite can be dangerous and should be avoided. To start with, the teeth are slightly backward-facing, so that when they bite there is a ‘pull-back’ effect when you react (not unlike a barb on a fish hook). They are not aggressive as such, but they know how to deal with unwanted interference in their lives…

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

Apart from the unpleasant bite and associated pain that moray eels can inflict in defence, they are also poisonous (as opposed to venomous). Specifically they can release toxins into the wound; and in some species their skin contains toxins as well**. Serious infection may result.

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

CAN YOU GIVE THE POISONOUS / VENOMOUS DISTINCTION AGAIN

I could, but ace natural history cartoonist Rosemary Mosco makes a better job than I can:Toxic: poison v venom cartoon (Rosemary Mosco)

**Before I leave the topic, maybe I ought to mention one bit of research I have just come across at Dove Med, from which I take away the message that you definitely don’t want to annoy a moray eel or get bitten by one. Ever. They are fine and interesting denizens of the reef, to be admired from a respectful distance…

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

Photo credits: all amazing photos courtesy of Melinda Riger, Grand Bahama Scuba; cute yet educative cartoon by Rosemary Mosco. Check out her website HERE – and birders, she v good on your specialist subject…

Spotted Moray Eel (©Melinda Riger / Grand Bahama Scuba)

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN


Hawksbill Turtle Bahamas (Melinda Riger / G B Scuba)

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN

Pliny the Elder (CE 23–79) was one of the earliest naturalists, besides being a philosopher, author and military commander. He wrote Naturalis Historia (Natural History), a wide-ranging work that became a model for later scholarly works, including forms of Encyclopedia. And, as he so nearly wrote, ‘si non amas testudines, vacua anima tua est’ (he that loves not sea turtles, has an empty mind)*

Hawksbill turtle grazing while a French angelfish looks onHawksbill Turtle with French Angelfish, Bahamas (Melinda Riger / G B Scuba)

There can be few better ways to start the New Year than with some gorgeous Hawksbill Turtles  Eretmochelys imbricata, plus a sprinkling of turtle facts to give 2019 a good push into orbit. Fortunately still available in Bahamas waters, the continued existence of Hawksbills is under serious threat. Make the most of your opportunities.

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

  • Guesstimates of the world Hawksbill Turtle population suggest that there are 5 main groups in the oceans, with few enough individuals – especially breeding females – to warrant an IUCN listing of the species as critically endangered
  • I doubt that many will forget that the next IUCN category is… extinct (≠ ‘fun fact’)
  • The largest Hawksbill colony in the world nests on an island in Queensland Australia
  • Turtles leave the sea to lay eggs in a hole dug on the beach, before returning to the sea.
  • The eggs hatch after c60 days… the turtlings emerge and are then on their own
  • Hawksbills are omnivorous, mainly eating sponges (& immune from sponge toxins)
  • They also eat sea anemones, mollusks, and jellyfish
  • Their grazing lifestyle is an important component of a healthy coral reef ecosystem

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

  • Though their shells are hard, Hawksbills are prey for sharks, crocodiles, octopuses and the biggest predator of all, humans“.
  • Despite international Hawkbill protection and conservation measures, they continue to be illegally hunted – including, in some places, for food.
  • Their lovely shells – tortoiseshell – are illegally traded for use for ornaments and jewellery
  • Japan makes its own rules (as with whales) for traditional & no doubt research purposes
  • ‘Tortoiseshell’ is the illegal item most frequently confiscated by custom officials
  • Reef and beach degradation, development, light pollution (confuses the baby turtles trying to paddle to the sea), ocean pollution / marine debris, and illegal practices are among the greatest dangers to the survival of the species. All are caused, directly or indirectly, by you and indeed me

Hawksbill T ©Melinda Riger + G B Scuba copy.jpg

Credits: wonderful photos by Melinda Riger / Grand Bahama Scuba (1, 2, 5) & Adam Rees / Scuba Works (3, 4, 6); Widecast; Nature Conservancy; OneKind Planet

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

* Do not believe this – I invented it. The quote that props up the pretentious stuff, that is – all the rest is true…

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)