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

JAW-DROPPING: A GROUP OF GROUPER(S)


Grouper at cleaning station - Melinda Riger @ GB Scuba

JAW-DROPPING: A GROUP OF GROUPER(S)

Today is going to be about Jaws – not those sinister-music-sharky types, but a look at the dentition, gill arrangements and oral hygiene of groupers(s). First, though, the vexed question of the correct plural for a group of these fish. I tackled the complex 3-option correct plural of OCTOPUS a while back. Now another problem piscine plural has cropped up.

Tiger Grouper - Melinda Riger @ G B ScubaThe short answer is that the plural is usually ‘groupers’, but also – perhaps less commonly – ‘grouper’ (there’s a similar situation with plural of ‘hare’). One online source suggests ‘grouperer’, but that just seems cumbersome. I think there may be a useful distinction to be made here. When talking about grouper of the same species, one could say “I saw 17 Nassau grouper today”. But where reference is made to mixed species, “I saw plenty of groupers today” implies that there was more than one species – black and tiger, maybe. 

Grouper at cleaning station - Melinda Riger @ GB Scuba

Grouper - Melinda Riger @ G B Scuba

In some of these photos you’ll notice tiny fish attending to the grouper. These are CLEANERS and they are an essential part of the bodily and oral hygiene routine for larger fish species. The big fish call in at so-called CLEANING STATIONS, where the tiddlers remove parasites and dead skin, and polish up the gills. They will even enter the fish’s mouth to pick bits from between its teeth – the deal being that they will not be eaten. This mutually beneficial arrangement is called ‘cleaning symbiosis’ and is carried out by (for example) gobies, wrasses and cleaner shrimps.

Peterson’s cleaner shrimps and cleaner wrasseGrouper with Peterson's cleaner shrimps and wrasse - Melinda Riger @ GB Scuba

Some of these photos show groupers with open gills as well as open mouths, an invitation to the cleaners to do their work. I’d intended to write about how and why gills work but I’ve thought better of it. There’s a lot of detail about chemical exchange involved that, when I looked more closely, seemed rather dull… and therefore outside the remit of this blog, which includes trying to avoid ‘dull’. If you really want to know more, Wiki has a good article HERE. Good luck with that….

Grouper - Melinda Riger @ GB Scuba

Credits: All photos Melinda Riger, Grand Bahama Scuba

SUBMARINE SUPERMODELS: POUTS & GLAM EYES OF BAHAMAS REEF FISH


SUBMARINE SUPERMODELS

THE POUTS & GLAM EYES OF BAHAMAS REEF FISH

I have been idly filing away some stunning close-up reef denizen images by Melinda Riger. A Monday morning is the perfect time to showcase some pouts, poses and glad eyes from the ‘catfish walk’, starting with my absolute favourite…

A COWFISH** PERFECTS THE POUTCowfish ©Melinda Riger @ Grand Bahama Scuba

A GREEN MORAY EEL SMILES STRAIGHT TO CAMERAGreen Moray Eel ©Melinda Riger @ Grand Bahama Scuba copy

THE QUEEN ANGELFISH ‘LOVES’ THE LENSQueen Angelfish © Melinda Riger @ G B Scuba

A GROUPER DOES THE ‘OPEN-MOUTH’ GAPE'Bruno' ©Melinda Riger @ G B Scuba copy

THIS SCHOOLMASTER SNAPPER MAY NOT HAVE GOT QUITE WHAT IT TAKESSchoolmaster Snapper ©Melinda Riger GB Scuba copy 

NICE EYES, BUT THE PETITE SAND-DIVER NEEDS TO BE A LITTLE MORE OUTGOINGSand Diver Fish copy

AS DOES THE SOUTHERN STINGRAYSouthern Stingray ©Melinda Riger @ GB Scuba copy

HOWEVER THE PEACOCK FLOUNDER IS ROCKING THE MAKE-UP BOXPeacock Flounder Eye ©Melinda Riger @ G B Scuba copy

THE OCTOPUS IS MOODY &  WON’T GET OUT OF BED FOR LESS THAN 20 MOLLUSCSOctopus ©Melinda Riger GB Scuba copy

AND REGRETTABLY THE POOR CONCH HAS A BAD STAGE FRIGHTConch Eyes ©Melinda Riger @ Grand Bahama Scuba copy 2

For more octopus information and a discussion of the correct plural (choice of 3) CLICK HERE

For a post about underwater species camouflage CLICK HERE

**Since I posted this earlier today, I have been asked (re photo 1) what the… the… heck a Cowfish looks like, when it’s not puckering up while facing you. The answer is: stunningly glamorous…

Cowfish ©Melinda Riger @ Grand Bahama Scuba copy

Thanks as ever to Melinda Riger of Grand Bahama Scuba for use permission for her fab photos; tip of the dorsal fin to Wiki for the shark eye header pic