ENDANGERED SPECIES, ABACO (3): NASSAU GROUPER


Nassau Grouper (Melinda Riger / G B Scuba)

ENDANGERED SPECIES, ABACO (3): NASSAU GROUPER

The Nassau grouper Epinephelus striatus is one of a number of grouper species found in Bahamian waters. Of these, only the Nassau grouper is on the IUCN Red List, as Critically Endangered. When I last wrote about them they were in the lesser category ‘Threatened’.

Nassau Grouper (Melinda Riger / G B Scuba

In order to sustain a viable population, it is vital to maintain numbers and preferably to increase them year on year. Once it became clear that year-round commercial overfishing was a prime component of the steep decline in the population, a 3-month closed season during the breeding period was imposed. This has ensured that at the most critical time in the lifecycle of the species, the groupers are left alone to breed in peace and to perpetuate their species.

Nassau Grouper (Melinda Riger / G B Scuba)

The closed season operates from December to February to maximise the chances of breeding success. As with some other fish species, reproduction occurs around the full moon. The fish gather at spawning sites and the process is at its height around sunset.

Nassau Grouper (Melinda Rogers / Dive Abaco)

10 CONVENIENTLY COLLECTED NASSAU GROUPER FACTS

  • An adult can grow to more than a metre long, and weigh 25 kg
  • They tend to be solitary daytime feeders, eating small fish & crustaceans
  • Their large mouths are use to ‘inhale’ or suck in prey
  • The colouring of an individual can vary from red to brown
  • These fish have little black spots around the eyes (I’ve no idea why).
  • Their habitat is in the vicinity of coral reefs, from shallows to 100 m deep
  • Spawning mainly occurs in Dec & Jan during a full moon
  • Large numbers gather in a single location to mate in a mass spawning
  • These groupers are slow breeders, which compounds the overfishing problem
  • They are easy mass targets at spawning time; hence the need for a closed season

Nassau Grouper (Melinda Riger / G B Scuba)

A Nassau Grouper glumly contemplates the possibility of extinctionNassau Grouper (Melinda Riger / G B Scuba)

RELATED POSTS

BLACK GROUPER

TIGER GROUPER

RED HIND

CLEANING STATIONS

Nassau Grouper (Melinda Rogers / Dive Abaco)

Credits: Melinda Riger / Grand Bahamas Scuba (1, 2, 3, 5, 6); Melinda Rogers / Dive Abaco (4, 7)

GROUPER AT THE CLEANERS: PICTURE PERFECT BAHAMAS (5)


GROUPER AT A CLEANING STATION: PICTURE PERFECT BAHAMAS (5)

BLACK GROUPER AT A CLEANING STATION (Melinda Riger @ G B Scuba)

This black grouper (‘Arnold’) is at a so-called CLEANING STATION, being groomed by gobies. The process is an example of species symbiosis known as MUTUALISM. This is a transaction between individuals of two species that is mutually beneficial. Here, the primary creature pauses at a locally familiar cleaning station and allows itself to be expertly cleaned by tiny fishes such as gobies and wrasses to remove parasites, dead skin and so forth. This nurture even includes, as here, inside the mouth and gills. The gobies benefit by feeding on the proceeds of their endeavours removed from the host (or ‘client’ as one might say). And of course, in return for their favours a collateral benefit is that they can feed freely without being eaten by a potential predator. 

Credit: Melinda Riger / Grand Bahama Scuba

WRY ‘CUDA & SARDONIC SMILES, ABACO BAHAMAS


Barracuda, Abaco Bahamas (Melinda Rogers / Dive Abaco)

WRY ‘CUDA & SARDONIC SMILES, ABACO BAHAMAS

There’s no doubt about it, barracudas have a particularly unwelcoming look to them. They exude menace. There’s something about the torpedo shape, the primitive head, and the uncomfortably snaggle-toothed grin-with-underbite that suggests a creature not to be underestimated.

Barracuda, Abaco Bahamas (Melinda Rogers / Dive Abaco)

And that smiley mouth – rather scornful and derisive, is it not? A powerful creature in its element, where you are the intruder… and it sees it like that too. An adult barracuda may grow to nearly 6 foot long. Your are only temporarily of its world, and (it observes) you are keeping your distance.

Barracuda, Bahamas (Melinda Riger / G B Scuba)

The dental arrangements of a ‘cuda are a wonder in themselves. The teeth are razor sharp; an orthodontist’s nightmare because they are all different sizes and grow at different angles. Some are conventionally set in the jaws, but some actually grow from the roof of the mouth. There are ‘normal’ sized teeth interspersed with wicked-looking fangs that randomly grow facing forwards, backwards and sideways.

Barracuda, Abaco Bahamas (Melinda Rogers / Dive Abaco)

WHY THE UNTIDY MOUTH FURNITURE?Barracuda, Abaco Bahamas (Melinda Rogers / Dive Abaco)

The name Barracuda is thought to derive from the Spanish word barraco meaning (in one of its senses) “overlapping teeth”. The jaws that contain the teeth are strong, and the underbite adds to the effectiveness of ‘cuda predation. Prey is highly unlikely to escape once caught.  When the jaws snap shut, the sharp angled teeth – particularly the back-facing ones (cf fishhook barbs) prevent the victim from pulling away. Then the munching and shredding can begin inside what is essentially a perfectly equipped multi-bladed mincing machine.

Credits: Melinda Rogers / Dive Abaco except #3 & #8  Melinda Riger / Grand Bahama Scuba

Here’s looking at you…

EEL-SPOTTING: FORAYS WITH MORAYS (7)


Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

EEL-SPOTTING: FORAYS WITH MORAYS (7)

MORAY EELS are plentiful around the reefs of the Bahamas. Some species, anyway. The ones you are most likely to encounter are green morays, and the spotted morays shown here. Less common are chain and golden-tail morays and, rarer still I suspect (because I have only  one image in the archive…) is the ‘purple-mouth’.  

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

Despite their moderately intimidating appearance – an adult may grow to 1.5 meters or more, with sharp teeth at the front end – these eels are not especially aggressive unless provoked. Best to assume that all humans will behave respectfully around them and remember that people are the intruders in the eels’ domain. 

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

Morays tend to be loners of the reefs, but they do gather in groups from time to time. And as shown below, they will also hunt with other species, for example this tiger grouper.

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

Sharp-eyed, sharp-toothed

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

Looks friendly enough…

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

A long and surprisingly large body, generally concealed in the crevices of the reef

Spotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

Credits: Melinda Riger / Grand Bahama Scuba

Lurkin’ GoodSpotted Moray Eel, Bahamas (Melinda Riger / G B Scuba)

BAHAMAS REEF LIFE (1): FRENCH ANGELFISH


French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

BAHAMAS REEF LIFE (1): FRENCH ANGELFISH

The massive destruction and dislocation caused on both Abaco and Grand Bahama by Hurricane Dorian is well-documented. The regeneration of both islands is making unsteady progress towards a stability that still seems many months away. In many locations it is still ‘two steps forward, one step back’. It remains a moot point whether ‘normality’, as it was just over 2 months ago, will ever be quite the same again.

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

We know how things are on land. As far as Abaco is concerned, few people can say how the coral reefs have been affected by the massive storms. Boats that were not flung ashore were sunk instead. Marinas and their infrastructure all but disappeared. 

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

Dive Shops, like so many thriving businesses in MH, have been reduced to rubble by this cruellest of extreme tropical storms. For the time being at least, they are damaged beyond use. I have seen no reports about the conditions in – for example – Fowl Cays National Park, a coral and reef-life rich marine preserve that was directly in the hurricane’s path. It may be weeks before an assessment can be made.

French Angelfish juv, Grand Bahama (Melinda Riger/ G B Scuba)

Happily, Melinda and Fred Riger of Grand Bahama Scuba have very recently been able to reopen their business. Melinda is, as regular readers will know, a wonderful underwater photographer. She kindly gives me the freedom of her extensive photo archive, accumulated over many years. The focus today is on French angelfish on the reefs of Grand Bahama.

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

Many of the photos here have been taken during the last 3 weeks or so, as diving becomes more of a daily exercise and customers are able to return to explore the underwater world of the reefs. Adult French angelfish have handsomely decorated flanks and golden eye-rings. The small striped ones with blue flashes on their fins are juveniles.

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

There are three angelfish species in the northern Bahamas – Queen, Gray and French. I have chosen to feature French angelfish because as it happens the juveniles of the species found since Dorian by Melinda and Fred may provide some insight into the subsurface effects of this huge storm.

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

As is evident from Melinda’s recent photos, the reefs off the south coast of Grand Bahama are relatively unscathed. Corals that she and Fred planted after the last hurricane have ‘taken’ and remain in place. However the juvenile fish now being seen nosing around the reefs in quantity may tell a story of disruption elsewhere.

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

The juvenile angelfish – as with the young of many other species – tend to live in the relative safety of the mangroves as they grow towards adulthood and are ready to move to the reefs. However, the unusual numbers of juveniles seen in the open during recent weeks suggest that the storm-damage to mangrove swamps in shallower water has unexpectedly displaced the juveniles to the reefs. 

French Angelfish, Grand Bahama (Melinda Riger/ G B Scuba)

This theory seems to apply to juveniles of other species recently encountered. What can be said is that, if even if displaced, there are plenty of healthy juvenile as well as adult fish around. And the justifiable  fears of serious damage to the corals have not been borne out. It remains to be seen whether a similar situation exists in Abaco waters.

French Angelfish juv, Grand Bahama (Melinda Riger/ G B Scuba)

Credits: all fantastic photos, Melinda Riger / Dive Abaco. It’s great that you have been able to reopen the business and restart having been forced to suspend operations completely.

French Angelfish juv, Grand Bahama (Melinda Riger/ G B Scuba)

WTF? (WHAT’S THAT FISH?): THE FROGFISH


Frogfish (Adam Rees / Scuba Works)

The Astoundingly 5* Strange Frogfish (Adam Rees / Scuba Works)

WTF? (WHAT’S THAT FISH?)

A COMPENDIUM OF SUBSURFACE WEIRDNESS

A SERIES OF 15 OF THE STRANGEST SEA CREATURES IN BAHAMAS WATERS

INTRODUCTION

WTF? stands for ‘What’s That Fish’? But it might also be your exclamation when you come across one of these creatures. The WTF? series highlights some of the unusual, curious, weird and downright extraordinary fishes that inhabit the waters of the northern Bahamas. Some represent local forms of a species found elsewhere in the world; others are in their own evolutionary cul-de-sac. Just as I think I have seen it all, so another oddity crops up somewhere that demands inclusion. 

The WTF? series, put together over several years, is intended to be the most direct route to an underwater menagerie of piscine strangeness, with some great photos to whet your appetite to learn more about these fascinating denizens of the ocean. 

1. THE FROGFISH

* CLICK ON THIS TITLE TO BE TRANSPORTED TO THE STRANGE WORLD OF THE FROGFISH *

Frogfish (Adam Rees, Scuba Works)Credits are given in the individual articles. Thanks to all those that have provide the photos, without which this type of illustrated, unscientifically scientific poke around in the ocean depths would not be possible.

HIDDEN DEPTHS: LIFE ON ABACO’S CORAL REEFS


Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

HIDDEN DEPTHS: LIFE ON ABACO’S CORAL REEFS

Nearly 4 weeks after the devastation of Hurricane Dorian, the island and its cays are beginning to emerge gradually from the wreckage and the desolation. The extent of the disaster on the ground is clear, not least from the aerial photos – first drone, then plane, and now Google – of ‘before’ and ‘after’. 

Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

At the stage, it isn’t possible to determine the extent to which the underwater world has been affected. The storm surge was huge and the waves were savage. The progress of the storm was slow (and it went on to stall over equally damaged Grand Bahama). Who knows the effect on the corals and other reef life for which Abaco is renowned.

Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco) Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

This pictorial post is a reminder of how things were below the surface of Abaco waters before Dorian struck. If it lifts spirits to any degree, I shall be glad.

Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco) Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

All these photos are by Melinda Rodgers who, with Capt Keith, are DIVE ABACO. Many will know how badly they have fared, being in the heart of Marsh Harbour. We wish them a speedy return to the wonderful enterprise they have run for many years. I’m pleased to be able to show the beauty of the reefs in happier times from their archive.

Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

Credits: Melinda Rodgers /  Dive Abaco

Reef Coral Abaco Bahamas (Melinda Rodgers / Dive Abaco)

BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF


BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

I’ve gone pictorial for today because I have only got my phone with me while we are away. Composition is slow, close to decomposition – and the comms connection is close to disconnection

Blue chromis (Chromis cyaneus) belong to the same group of fishes as damselfishes. These unmistakeable, bright reef denizens are very visible despite their tiny size. These fish are shoalers, so out on the reef you can enjoy them flickering around you as you swim along or hang in the water to admire the corals.

Like many a pretty and easily captured small fish that can be monetised once removed from its natural home environment, the blue chromis is popular for aquariums, and for humans to keep in their own home environments, unselfishly feeding them concocted food.

Blue chromis are adaptable and sociable, and will happily swim with other small reef fishes (as above). My own favourite combo is chromis mixed in with sergeant majors. But a shoal of them (mostly) alone is pretty special too….

I cynically mentioned ‘concocted’ food earlier. Here is one online care instruction for looking after them: “They are omnivores, meaning that they eat both meaty and plant based foods. They are not difficult to feed and will eat a variety of regular aquarium fare, frozen, live, and sometimes even dry food. Feeding them a variety of foods will help them retain their color in captivity. They sometimes feed on the algae in the tank”. 

If you are tempted to rescue some from their reef habitat, rest assured that: They have been known to spawn in captivity. Blue chromis can usually be obtained for about $10-15. And don’t hold back on the frozen food (though maybe warm it up a bit before feeding time).

Credits: Melinda Rodgers / Dive Abaco; Melinda Riger / G B Scuba

BAHAMAS REEF FISH (53): YELLOW GOATFISH


Goatfish, Bahamas (Melinda Riger / G B Scuba)

BAHAMAS REEF FISH (53): YELLOW GOATFISH

GOATFISHES belong to the mullet family, a large group of species with a flexible membership. In other words, there is disagreement as to whether certain fish are mullet or not. For present purposes, it’s not our problem – no one doubts that the goatfish is a mullet.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

SO WHY ARE THESE CALLED GOATFISH? WAS SOMEONE KIDDING?

These fish get their name for the pair of so-called ‘barbels’ below their mouths (see image below), thought to be reminiscent of a goatee beard. The name has Latin origin, ‘barbula‘, meaning a small beard. Linnaeus may have had a hand in this choice of description.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

WHAT IS THE FUNCTION OF THE BARBELS?

The barbels are sensory organs which, depending on the creature, may be located on either side of the mouth, on the chin, or even extending from the nostrils. In broad terms, the barbels are where the taste buds are located. They help a fish to find food even when the water is stirred up or murky or at night, and are used to probe into sand or into holes in the reef for prey.  

Goatfish, Bahamas (Melinda Riger / G B Scuba)

WHY ARE THEY OFTEN SEEN WITH YELLOWTAIL SNAPPERS, GRUNTS & PORKFISH?

Goatfish have limited means of self-protection. They are not poisonous or venomous, they have no spines or razor-sharp teeth, nor ink to squirt. They do have an ability to change colour rapidly to blend into their surroundings – e.g. over pale sand – to make them less conspicuous to predators. Overall, however, they are docile and probably delicious to many other species. Their bright hues may have some function as aposematic colouring to warn, scare or repel potential predators, but this is possibly of limited use among the familiar reef denizens. So instead the goatfish goes in for so-called protective mimicry, as shown in the image above.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

PROTECTIVE MIMICRY?

Goatfish and yellowtail snappers (in particular) are similar in size, appearance, coloration and behaviours, though the feeding patterns differ. The reason they are often found in mixed groups on the reef is for the individual protection they gain in a larger mixed school. This really amounts to taking advantage of safety in numbers (especially for the fishes in the middle). Here’s a very recent photo that shows exactly this scenario – a large mixed shoal of two almost indistinguishable fish species.

Goatfish & Yellowtail Snappers shoaling (Melinda Riger, GB Scuba)

IS THIS A ‘SPOT THE DIFFERENCE’ TEST?

If you’d like to make it so! (click on the image to enlarge it). Look out for the fish with the barbels (Goatfish); and the fish with the larger, more deeply forked tails (Snappers). A predator won’t take a great deal of notice of the finer points of difference of course, but overall this large mixed shoal gives a degree of protection to individual fish in the unit as a whole

Goatfish, Bahamas (Melinda Riger / G B Scuba)

ARE GOATFISH EDIBLE?

Goatfish are eaten in many ares of the world, though I can’t recall seeing it on a Bahamian menu. The Romans ate the local mullet / goatfish species, but then they ate many things that we do not now consider as permissible food – dormice in honey for example. Rather revoltingly, the goatfish were served live so that guests could watch them die and see the amazing change of colours in the process. Barbaric? But don’t we cook live… well, never mind that.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

Photos: all great photos from Melinda Riger / Grand Bahama Scuba; magpie research pickings inc. the abstract of a scientific paper with about 23 authors; tip ‘o the hat to Wiki, no seriously

Goatfish, Bahamas (Melinda Riger / G B Scuba)

PEACOCK FLOUNDERS REVISITED: NOW YOU SEE THEM…


Peacock Flounder (Melinda Riger / G B Scuba)

        PEACOCK FLOUNDERS (Part Deux)

MASTERS OF SUBAQUATIC CAMOUFLAGE

I featured the extraordinary, colour-transforming PEACOCK FLOUNDER Bothus lunatus about 3 years ago in the Bahamas Reef Fish series (No. 21 I think). These really are remarkable creatures, and I am pleased to be able to show some more wonderful illustrative photos. 

Peacock Flounder (Melinda Riger / G B Scuba)

ROVING EYES

In the fish shown here, you’ll see that – surprisingly – both eyes are on the upperside of the fish, above the rather grumpy mouth, whereas the head is horizontal to the ocean floor. Oddest of all, juveniles are constructed conventionally with bilateral eyes, and look like ‘normal’ fish rather than flatfish.

Peacock Flounder (Melinda Rogers / Dive Abaco)

As the fish matures, in some magic way the mechanics of which I can only guess at**, the right eye grows round to the topside and the flounder transforms from a ‘vertical’ fish to a flatfish. For this reason, the PF is known as a ‘lefteye’ flounder. Maybe in other flounder species in the world – the southern hemisphere maybe? – the eye that moves round to the upperside is the left eye.

Peacock Flounder (Virginia Cooper / G B Scuba)

The eyes of this fish have another special trick up their sleeves (so to speak). They operate completely independently. Thus the creature can look left and right, or forwards and backwards, simultaneously. It’s an excellent system for detecting predators coming from any angle. It’s a superpower we might all benefit from.

Peacock Flounder (Melinda Rogers / Dive Abaco)

DO THEY HAVE ANY OTHER TRICKS WE SHOULD KNOW ABOUT?

Yes they do indeed. If you have been admiring the fish shown so far, you’ll have noticed that the colour of each one differs from the others. In addition to the predator-protection that the eyes provide, the peacock flounder can make itself (near) invisible. They can rapidly change colour to match their surroundings. There are 3 reasons for this: to avoid / confuse predators; to conceal themselves on the sea-floor to catch passing prey; and, as dive expert Fred Riger has pointed out, “the male peacock flounder can, and does greatly intensify his colours to declare territory and attract females. When doing this the males will also signal with the left pectoral fin, sticking it straight up and waving it around.” 

The same fish, photographed over several minutes as it moves over the ocean floorPeacock Flounder (Wiki)

Matching the background happens as the fish swims, and in a few seconds. When they rest on the sea-floor, the camouflage may even become total. In #4 above you can just about make out the eyes. The whole effect is known as ‘cryptic coloration’ or CRYPSIS. In contrast, the image below shows just how adaptable the transformation can be. Note how the fish can even mimic the pinkish tinge of the sand perfectly. If threatened, the fish will bury itself in the sand, with just its eyes showing.

Peacock Flounder (Melinda Rogers / Dive Abaco)

HOW DO THEY MANAGE TO CHANGE COLOUR IN SECONDS?

It’s complicated! A simple answer is: a mix of hormones, pigment-cells and vision, all coordinating rapidly. The colour change works in two ways: pigments are selectively released to the skin cells; and other pignments can be selectively suppressed. An analogy might be image manipulation using variations in brightness, saturation etc. Not convinced? Then watch this short video and prepare to be impressed. Astonished, even.

WHAT IF A FLOUNDER CAN’T SEE CLEARLY FOR SOME REASON?

As with many (all?) superpowers, there is usually some kryptonite-style flaw. A flounder with a damaged eye, or one temporarily covered (by sand, for example) will have difficulty in changing colour – possibly at all, or at any rate with the swiftness it needs to have. 

Peacock Flounder (Melinda Riger / G B Scuba)

THESE SIDEWAYS FISH – HOW DO THEY… YOU KNOW…?

Take a look at the fish above with its top fin raised. It’s a ‘ready’ signal in a harem. Male flounders have a defined and defended territory within which live up to 6 females – a so-called ‘harem.’ I can do no better than borrow the description of the rituals from an article derived from scientific papers by Konstantinou, 1994Miller, et al., 1991 in the website animaldiversity.org/…ounts/Bothus_lunatus To which I can only add, ’15 seconds, eh?’

Peacock Flounder (Melinda Riger / G B Scuba)

“Mating activities usually begin just before dusk. At this time, a male and a female approach each other with the ocular pectoral fin erect. The two fish arch their backs and touch snouts. After this interaction the female swims away, and the male sometimes follows, approaching the female again from the left side. At this point the male pectoral fin is erect and the female pectoral fin moves up and down, possibly signalling willingness to mate. The male then positions himself underneath the female and mating begins. This process consists of a mating rise, during which the female and male rise in the water column together. On average, these rises last about 15 seconds. At the highest point of this rise, usually around 2 m above the substrate, gametes from both fish are simultaneously released, producing a cloud of sperm and eggs. Once the couple returns from the rise, the male “checks” to make sure mating was successful, and the pair separates quickly, swimming away from each other in opposite directions. Not all mating rises are successful, and the process of “checking” is thus important. The exact purpose of the mating rise in these flounders unknown; possible reasons for rising include better dispersal of gametes and predator avoidance.” 

Peacock Flounder – Kim Rody ArtPeacock Flounder (Kim Rody Art))

**This may in fact be through sheer laziness

Credits: Melinda Riger & Virginia Cooper / Grand Bahama Scuba; Melinda Rogers / Dive Abaco; Adam Rees / Scuba Works; Kim Rody; animaldiversity.org; magpie pickings and other credits in the text

Peacock Flounder (Melinda Riger / G B Scuba)

MEET ARNOLD: BE A BAHAMAS BLACK GROUPER GROUPIE


Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

MEET ARNOLD: BE A BAHAMAS BLACK GROUPER GROUPIE

The Black Grouper, like all its cousins, has the twin disadvantages of being fished for sport and fished for food. As demand for grouper on the menu rises, so does its vulnerability. The species is described as a ‘slow breeder’, so a depleting population has less chance of sustaining numbers. The consequence is an exponentially diminishing stock of the species. The equation is simple: fewer fish means less and less stock replenishment.

Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

Formerly plentiful, these groupers (like other grouper species) have moved from an IUCN listing of ‘Least Concern’ to ‘Near-Threatened’. Whatever effect climate change may be having on the oceans, stock depletion of this noble species also has more direct human causes.

Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

An adult black grouper’s diet consists of small fish and squid. Juveniles feed primarily on crustaceans. However, certain tiny reef fish – blennies and gobies for example – are important to the species as ‘cleaners’. You can read about their significance by clicking CLEANING STATIONS.

Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

The service performed by tiny fish on large ones (not only groupers) is an example of a symbiotic relationship known as ‘mutualism’**, in which both parties benefit (the little fishes get gacky bits of grouper to eat). The cleaners are able to do their work inside the gills and even the mouth of the host without being at risk.

Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

The NASSAU GROUPER has a defined and enforced closed season to help maintain numbers. It will be interesting to see if the same protection is eventually extended to the black grouper and indeed to other grouper species.

** The other two types of symbiotic relationship are commensalism, in which only one species benefits while the other is neither helped nor harmed; and parasitism, where one creature (the parasite) gains, while the other (the host) suffers.

RELATED POSTS

TIGER GROUPER

NASSAU GROUPER

RED HIND

GRAYSBY

Credits: all photos Melinda Riger of Grand Bahama Scuba 

Black Grouper, Bahamas (Arnold) - Melinda Riger @ GB Scuba

ROCK BEAUTY: BAHAMAS REEF FISH (52)


ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

ROCK BEAUTY: BAHAMAS REEF FISH (52)

I last featured the cheerfully-coloured Rock Beauty Holacanthus tricolor 2 or 3 years back. Time has passed; new photos exist; new people have signed up to follow this eclectic menagerie (thank you both). Time for another look at these beauties, which also happen to be cuties.

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

Look at the little guy above –  posing for Pixar, adorably hoping to star in Part 3 of the Nemo / Dory trilogy

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

These fish are a small species of angelfish. Seen swimming around the reefs they are unmistakeable, not least because of their bright yellow hi-viz jackets, remarkable blue eyeliner and blue-black lippy. 

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

Rock Beauties look like prime candidates for anyone’s aquarium, but their picky dietary requirements and tendency for aggression make them unsuitable.

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

They are highly specialised feeders, needing marine sponge in their daily diet. They are also prone to chase their tank-mates and nip them. On balance, they look more fetching nosing about the coral anyway.

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

WHAT DO JUVENILES LOOK LIKE?

Juvenile rock beauties are cute mini-versions of the adults, only more yellow and with yellow lips. In some development stages, they have a smart blue circle around the dark patch on their sides (bottom image).

ROCK BEAUTY: BAHAMAS REEF FISH (Melinda Riger / GB Scuba)

Rock Beauty, Bahamas (Living Oceans Foundation))

NOTE Rock Beauties have no known kinship with Chrissie, Debbie, Lita, Joan, Jennifer, Stevie, Madge and the rest of the accredited ‘Rock Beauties aka Chicks’ 

NOT A TRUE ‘ROCK BEAUTY’ (no offence, Lita)

A TRUE ROCK BEAUTY

Credits: Melinda Riger, Grand Bahama Scuba; WP

‘REEF ENCOUNTER’ 1: GRAY ANGELFISH


Gray Angelfish 9with four-eyed butterflyfish), Bahamas (Melinda Riger / Grand Bahama Scuba)

‘REEF ENCOUNTER’ 1: GRAY ANGELFISH

Today I learn from a cheery message from WordPress that my illustrated ramblings have been going on for exactly X years, where X is greater than 5 but less than 10. Time to start a new theme: channelling my inner Noel Coward, I am introducing a new mainly pictorial series provisionally called ‘Reef Encounter’. All the awesome beauty of reef life will be here.

Gray Angelfish, Bahamas (Melinda Riger / Grand Bahama Scuba)

In the past I have posted about GRAY ANGELFISH, one of three kinds of angelfish found in the northern Bahamas. Today, I am featuring some more recent images of these pretty creatures. Note in particular the striking shape and colour of their mouths, the blue being found also on the fin edges at the back.

Gray Angelfish, Bahamas (Melinda Riger / Grand Bahama Scuba)Gray Angelfish, Bahamas (Melinda Riger / Grand Bahama Scuba)

On this otherwise gray fish, you’ll also find touches of yellow on the face and the edges of the front fins. In the header image there’s another little fish in the bottom right corner. Not a baby angelfish, but a FOUR-EYED BUTTERFLYFISH – a species that will feature in own right in due course

Gray Angelfish, Bahamas (Melinda Riger / Grand Bahama Scuba)

All fabulous photos by Melinda Riger / Grand Bahama Scuba

Gray Angelfish, Bahamas (Melinda Riger / Grand Bahama Scuba)

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)

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 (49): BANDED BUTTERFLYFISH


Banded Butterflyfish, Bahamas (Melinda Riger / GB Scuba)

BANDED BUTTERFLYFISH – BAHAMAS REEF FISH (49)

The banded butterflyfish (Chaetodon striatus) is one of several butterflyfish species found in Bahamas waters. There are links to some of the others at the end of this post. The reason for the name is obvious. The purpose of the patterning (striatus) is to act as an adaptive anti-predator defence when seen against the varied landscape of the coral reefs that are its home. 

Banded Butterflyfish, Bahamas (Melinda Riger / GB Scuba)

These little fish tend to be found either singly or in pairs. Two of them together may play a form of chase game among the corals and anemones of the reef. 

Banded Butterflyfish, Bahamas (Melinda Riger / GB Scuba)

Banded butterfishes, like their cousins, have a varied diet that includes small crustaceans, worms, and coral polyps. They also have a valuable role on the reef by acting a cleaner fish for larger species like grunts, tangs and parrot fish. This sort of relationship, where one party benefits from this kind of interaction , is known as ‘commensalism’, one of the 4 types of symbiotic relationship.

Banded Butterflyfish, Bahamas (Melinda Riger / GB Scuba)

RELATED LINKS

LONGSNOUT BUTTERFLYFISH

BUTTERFLYFISHES (RH guide to reef, banded, four-eyed & spotfin)

REEF FISH INDEX gateway to loads of colourful finny species

WHAT’S THAT FISH? A handy resource

FLORENT’S GUIDE A ditto

Banded Butterflyfish, Bahamas (Melinda Riger / GB Scuba)

Credits: Melinda Riger / Grand Bahama 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