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)

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)

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)

BAHAMAS REEF FISH (48): SCHOOLMASTER SNAPPER


Schoolmaster Snapper (Melinda Riger @ G B Scuba)

BAHAMAS REEF FISH (48): SCHOOLMASTER SNAPPER

November 1st already, and the first time I am prepared to consider the possibility of the onset of Christmas, with its attendant joys yet complications… Meanwhile, I thought I might have run out of types of reef fish to feature in this series long before I got to 50. Yet here we are, two short of that target, with a species of snapper I haven’t even mentioned before. I am (frankly) a rather feeble swimmer, and do not possess a viable underwater camera. So there’s no way I could show these denizens of the not-especially-deep without heavy reliance on others, in particular the outstanding photos of diver Melinda Riger of Grand Bahama Scuba; and the memorable ones from Adam Rees of Scuba Works that include some of the more obscure species that appear in my WTF? (What’s That Fish) series. 

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

The schoolmaster snapper (Lutjanus apodus) lives among the coral reefs and mangroves of the Caribbean and further north to the northern Bahamas and Florida. Generally they are quite small, not much more than 12- 18 inches. They tend to hang out in ‘schools’, which several sources suggest as the reason they got their common name. But schoolmasters don’t really move around in large groups, do they? It’s school pupils that do that, but ‘Pupil Snapper’ wouldn’t cut it as a fish name I guess.

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

10 SCHOOLMASTER SNAPPER FACTS TO PONDER

  • One pair of upper teeth are so large they protrude when the fish shuts its mouth
  • Their side scales are so arranged that diamond shapes are produced
  • There’s plenty to learn about their fin arrangements, but not necessarily to remember
  • Their jaws don’t open very wide, so their prey tends to be quite small
  • Unlike fish that change sex as they grow, these ones retain their birth gender for life
  • When they spawn they produce their gametes simultaneously, and swim away
  • The fertilised eggs sink to the bottom, where they have to take their chances
  • Though small, they are good to eat and are fished for recreation and commercially
  • Regionally there are specific regulations as to catch length & limits, hook type, bait etc
  • Like all snappers and many other fish species, these fish are associated with ciguatera

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

RECIPES

For those who enjoy cooking (whatever that is), you probably know exactly how you like to cook your snappers. For anyone else, here’s a site that proposes several different ways to cook them, with helpful tips. These seem to apply to all snapper species, most of which are available free in the Bahamas. http://www.allfishingbuy.com/Fish-Recipes/Snapper-Recepies.htm

My favourite schoolmaster snapper photo of those featured hereSchoolmaster Snapper (Melinda Riger @ G B Scuba)

POSSIBLE MEDICAL BENEFITS FROM EATING SNAPPERS

These are alleged to include (except when fried): protection against certain types of stroke, reduction of heart arrhythmia, and defence against certain types of cancer. Don’t take my word for it, though. And definitely don’t rely on a snapper-based diet regime. I think the most that can safely be said is that eating snapper will do you no harm (except when fried) and may conceivably have a marginal benefit on health along with a balanced diet, exercise, minimal alcohol intake and all the routines that we strictly adhere to for a healthy life. In our dreams, anyway.

Schoolmaster Snapper (Albert Kok)

Credits: All great pics by Melinda Riger / GB Scuba except #6 Albert Kok; range map, Wiki. Magpie pickings.

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

 

BLACK DURGON: A TRIGGERFISH OF DISTINCTION


Black Durgon Triggerfish (Melinda Riger / Grand Bahama Scuba)

BLACK DURGON: A TRIGGERFISH OF DISTINCTION

The Black Durgon (Black Triggerfish) seems to be a fairly rare triggerfish in Bahamas waters. I say that not because I know, but because there is very little mention of them in a Bahamas context. In fact, the (not especially profound) research I have done suggests it is not (originally?) really native to the Bahamas region at all. Correction of this impression welcome!

Black Durgon Triggerfish (Melinda Riger / Grand Bahama Scuba)

These fish have the ability to change colour, according to their surroundings. Mostly, they seem completely black. However they have intricate blue markings to the head, and regular patterning on their flanks that resembles the sort of thing one idly doodles during a long and less then attention-holding phone call (or the ‘hold music’) – see Header Image. They also have dramatic pale stripes where their fins join the body.

Black Durgon Triggerfish (Getty Images)

These fish have a varied diet that includes small fish, squid and shrimps, with side-helpings of algae, zooplankton and marine plants. And…

FUN FACT (REALLY!)

The Black Durgon has been studied, of course. One piece of research discovered that they… erm… ingested the feces and vomit of a species of dolphin. Other reef fish in the area did so too, but the Black Durgon was much the keenest on this distinctive  diet. So these are ‘offal-eating’ fish… and welcome to it. Here’s a short video to take your mind off it all…

I’d be interested to hear from anyone who has encountered these fish in Abaco waters. I ought to look further into their prevalence. Maybe they just don’t get much publicity. They need a new agent.

Black Durgon Triggerfish (Melinda Riger / Grand Bahama Scuba)Credits: Photos by Melinda Riger / Grand Bahama Scuba except #3, Getty Images; Kwik-Viddy, Cassandra-Tel; inadequate research, Author

FORAYS WITH MORAYS (5): THE GOLDENTAIL


Goldentail Moray Eel (Melinda Riger / G B Scuba)

FORAYS WITH MORAYS (5): THE GOLDENTAIL

The Goldentail Moray Eel Gymnothorax miliaris is one of the half-dozen moray species found in Bahamas waters. Adults range in length from about 1.5 to 2.5 feet, and they are creatures of the reefs and rocks of the western Atlantic. As far as I can make out, the goldentails are rather less common than green or spotted morays, the two main eel species of the Bahamas.

Goldentail Moray Eel (Melinda Riger / G B Scuba)

Like their moray cousins, goldentails likes to keep themselves to themselves, and lead largely solitary lives. That said, sometimes they have been observed hunting in a group. They live in holes, clefts, and caverns which they leave both during the day and at night to hunt for prey along the reefs, aided by an acute sense of smell. Their diet is mainly of crustaceans, mollusks, and small fishes. 

goldentail-moray-eel-istock-getty-images-2

ARE GOLDENTAILS DANGEROUS?

Like many other eels, goldentails secrete a protective mucus that contains a toxin, making them unattractive prey for large predators such a groupers and barracudas. They are also associated with ciguatera poisoning, the active ingredients of which are found in the mucus coating. They are sometimes found in aquariums – the associated sites give a warning of painful bites, because they have backwards-pointing teeth (aka prey traps) – see header image for a clear view of this.

Goldentail Moray Eel (Melinda Riger / G B Scuba)
 
CAN YOU EAT THESE FISH?

Well I wondered that too, so I checked. The answer seems to be yes, if you real really want to. Comments on forums include:

  • “Yes they are edible, I just ate one few weeks ago. Some parts are little bony and skinning it is a bitch. But the meat is very soft and white, delicious. Deep fry works”. 
  • “After eating our moray eel something changed. The next morning, we were decidedly feeling ill. I won’t get into the details, but let’s just say that “gastrointestinal effects”
  • “…symptoms (of ciguatera) include gastronomic effects, and neurological effects which include headaches, numbness, paresthesia, muscle ache, and even hallucinations”.
  • “Before you can eat one you have to kill it. They are amazingly hard to kill. I would skip it.”
  • “I would rather eat a shoe”

So I’ll be moving straight on to the next course, please. Or just a Kalik would do, thanks.

goldentail-moray-eel-istock-getty-images-3

RELATED POSTS

SPOTTED MORAY EELS

GREEN MORAY EELS

goldentail-moray-eel-istock-getty-images-1.

Credits: Melinda Riger / Grand Bahama Scuba (1, 2, 4); iStock / Getty Images (3, 5, 6)

 

 

 

 

BAHAMAS REEF FISH (45) THREESPOT DAMSELFISH


Threespot Damselfish (Melinda Riger / GB Scuba)

BAHAMAS REEF FISH (45) THREESPOT DAMSELFISH

The threespot damselfish Stegastes planifrons is one of several damselfish types found in the Bahamas and more generally in the western Atlantic. As with so many reef species, there is a marked difference in coloration between juveniles (bright yellow) and darker-hued adults (above).

Threespot Damselfish (Melinda Riger / GB Scuba)Threespot Damselfish (Melinda Riger / GB Scuba)

These are bony little creatures, equipped with both spines and ‘soft rays’ on some of their fins. This perhaps make them unappealing to potential predators; and maybe the very brightness and ‘hi-viz’ of the juveniles is aposematic, a coloration thats acts as a warning or repellent to potential predators.

Threespot Damselfish (Melinda Riger / GB Scuba)

On the reef it seems threespots favour staghorn coral as a daytime base. Their diet is mainly seaweed, with small molluscs, gastropods and worms for variety. At night they retire to crevices and caves.

Threespot Damselfish (Melinda Riger / GB Scuba)

Adults are, for such small fish, vigorously protective of their territories. They will chase and nip intruders into their domains, even far larger creatures (up to and including humans).

Threespot Damselfish (Melinda Riger / GB Scuba)

A breeding pair will both be involved in egg care. Once the female has laid her eggs, they adhere to the lower reef and seabed. The male guards them and rather sweetly fans them with his fins to keep them oxygenated. And then another generation hatches and the threespot life cycle repeats.

Threespot Damselfish (Melinda Riger / GB Scuba)

Credits: All fantastic photos by Melinda Riger / Grand Bahama Scuba