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 (4): THE GOLDENTAIL


Goldentail Moray Eel (Melinda Riger / G B Scuba)

FORAYS WITH MORAYS (4): 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

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…”

BAHAMAS REEF FISH (43): CUBERA SNAPPER


BAHAMAS REEF FISH (43): CUBERA SNAPPER

The cubera snapper (Lutjanus cyanopterus) is the largest snapper species. Adults may grow to 5′ long but they average around 3′ long and weigh 40 lbs or so (the record apparently stands at a massive 126 lbs). These are game fish, and they are a commercially important species. They are also IUCN listed as vulnerable, perhaps for that very reason. 

10 CUBERA SNAPPER SNAPPY  FACTS

  • The largest of a large number of snapper species in the western Atlantic
  • Feed on fish, shrimps & crabs, with large strong teeth (see pics) and jaws
  • Among their (few) predators are sharks, barracuda, and moray eels
  • Edible, but beware of the danger of CIGUATERA poisoning
  • In summer months, spawning is governed by lunar cycles
  • Cuberas form huge spawning masses (to 10k) in offshore shallows
  • Sadly the resulting eggs and larvae are rich pickings for predators…
  • Youngsters live in sea grass or mangroves for protection
  • Cuberas are game fish with commercial importance
  • IUCN listed as vulnerable – largely courtesy of mankind (see »)

RANGE FINDER

Cubera Snapper Range Map (wiki)

CONSERVATION MATTERS

Overfishing is one of the greatest threats to the species. Those young fish that are not predated naturally and grow to adulthood are targets for fishermen. There’s no prissy ‘catch & release’, as with bonefish. At spawning time, as the fish instinctively (and predictably) mass as the moon dictates, so do the human predators. The spawning sites are where the best protection can be given, to ensure the annual reproductive cycle is uninterrupted. If not, ‘vulnerable’ will soon give way to ‘endangered’…

I’d been going to pull apart a long recipe for the “wonderfully sweet white meat ” of this fish for the tastiest morsels of info, then (not being a cook) I quickly tired of the idea. Sorry to disappoint. 

Credits: Melinda Riger for the wonderful photos; range map from wiki; magpie research pickings, including (but not limited to ) Nat Geo

GRAYSBY (GROUPER): BAHAMAS REEF FISH (42)


Graysby (grouper) - Melinda Riger / Grand Bahama Scuba

GRAYSBY (GROUPER): BAHAMAS REEF FISH (42)

The Graysby Cephalopholis cruentata is a small, spotty grouper, which grows to a maximum of around 16 inches. These rather unassuming and solitary fish have a preference for coral reefs, where they can blend in with their surroundings on ledges and in caves and crevices during the day. At night, they become active – that’s when they feed on feed on small fish, crabs and shrimps. 

Graysby (grouper) - Melinda Riger / Grand Bahama ScubaGraysby (grouper) - Melinda Riger / Grand Bahama Scuba

The graysby has variable colouring in a range from light brown to pale gray, with all-over spots that may be red, orange or brownish. Often, they have 3 to 5 contrasting spots on their backs, along the base of the dorsal fin, as below:

Graysby (grouper) - Melinda Riger / Grand Bahama ScubaGraysby (grouper) - Melinda Riger / Grand Bahama Scuba

The long erectile dorsal fin comprises both spines and ‘rays’ – spines at the front, rays at the back. Like this:

The spots of a graysby can change in colour (at least to a limited extent), becoming either paler or darker. I imagine this is a protective feature to enable the fish to blend in more easily with its reef surroundings. 

Graysby (grouper) - Melinda Riger / Grand Bahama Scuba

Signalling to turn right…

I wondered if they are edible. I believe so – but then I also read that the larger adults carry the risk of ciguatera and raised mercury levels. So I’ll give it a miss thanks.

Photo & other credits: all photographs by Melinda Riger / Grand Bahama Scuba; aqua.org; SAMFC (drawing)

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)