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

“CLEANING UP”: HOW TINY REEF FISH HELP LARGE FISH


Black Grouper - Arnold - Cleaning Station - Neon Gobies ©Melinda Riger @ G B Scuba copy

“CLEANING UP”: HOW TINY REEF FISH HELP LARGE FISH

A while ago now, I wrote a detailed post about so-called fish ‘cleaning stations’ – the special spots on the reef where large fish can go to have small fish buff up their scales and floss their teeth. You can read all about it HERE.

I have accumulated a number of new photos from expert scuba diver and underwater photographer Melinda Riger that demonstrate this phenomenon. A big fish with a normally voracious appetite will patiently wait while gobies and other small fry go about their work. This often involves actually entering the mouth of the (as it must seem to them) monster to pick the insides and the teeth clean. There is an extraordinary understanding and trust between the species that means during the operation, the little fish are perfectly safe. Here are some examples, of which the very recent header image of a grouper named Arnold is quite outstanding.

Tiger Grouper + cleaner goby ©Melinda Riger @ G B Scuba copyGrouper, Black at cleaning station ©Melinda Riger @G B Scuba copy Tiger Grouper at cleaning station ©Melinda Riger @ G B Scuba copy Tiger Grouper being cleaned ©Melinda Riger @G B Scuba copy

It is not just gobies that attend the fish. Various species of shrimp also volunteer for the job.

Tiger Grouper with cleaning shrimps and goby ©Melinda Riger @ G B Scuba copy Grouper being cleaned ©Melinda Riger @ GB Scuba copy

Groupers are not the only species to make use of cleaning stations. Here is a dog snapper at the same cleaning station as the grouper in the header image. Below is a stingray being attended to.

Dog Snapper at cleaning station ©Melinda Riger @ G B Scuba copy

Southern Stingray with cleaning gobiesStingray, Southern with cleaning gobies ©Melinda Riger @ G B Scuba copy

GRAMMATICAL DIGRESSION There is this ‘thing’ about the correct use of the words ‘fish’ and ‘fishes’ in the plural form. The basic principle is simple: ‘fish’ where you are referring to several of the same species; ‘fishes’ where more than one species is involved. I don’t care. My policy is to use ‘fish’ as the plural on all occasions, so I don’t have to think about it. Pedants, look away now.

RELATED POSTS

TAKEN TO THE CLEANERS

BANDED CORAL (‘CLEANER’) SHRIMP

TIGER GROUPER

BLACK GROUPER

All photos: Melinda Riger, Grand Bahama Scuba

RED HIND GROUPER: BAHAMAS REEF FISH (25)


Red Hind Grouper Melinda Riger @ G B Scuba copy

RED HIND GROUPER: BAHAMAS REEF FISH (25)

The Red Hind is one of several grouper species commonly found in  Bahamas waters. Commonly for now, anyway. There is less information available about this species compared with other groupers, but sources seem agreed that it is (a) abundant and (b) IUCN listed ‘least concern’ but (c) heavily fished and (d) delicious.

Red Hind, attended by Cleaner FishRed Hind Grouper ©Melinda Riger @ G B Scuba copy 2

Red Hind Grouper ©Melinda Riger GB Scuba copy

One problem arises from the fact that Red Hinds form spawning aggregations in particular areas, making them vulnerable to fishing exploitation in those locations, and consequent population decline. Already, some of their spawning areas are protected.

Another threat comes from the degradation of coastal habitats coupled with increasing commercial and recreational fishing.  Red Hinds are targeted with speargun, hook and line, fish traps and nets. They may also be by-catch of other fishing operations. Fortunately Marine Protected Areas such as the ones in Abaco waters provide localised protection but these are not found throughout the Red Hind’s range. Closed seasons have been imposed in a few areas, another conservation method that has recently been introduced in the Bahamas for the Nassau grouper. 

Female spawning Red Hind Grouper (Univ of Puerto Rico:NOAA)

Getting the right balance between traditional fishing for food, and stock conservation is inevitably a tricky calculation. For the Red Hind, the factors that may result in the population decline of a plentiful species are in plain sight and will continue to be monitored by the various scientific research organisations involved…

OTHER GROUPERS YOU MAY ENJOY…

NASSAU GROUPER

TIGER GROUPER

BLACK GROUPER

Red Hind Grouper ©Melinda Riger @ G B Scuba copy 3

Credits: All images Melinda Riger at Grand Bahama Scuba except (4) NOAA / Puerto Rico Univ; research from several sources, tip of the hat to SCRFA

BAHAMAS REEF FISH (22): BLACK GROUPER


Black Grouper ed ©Virginia Cooper @ G B Scuba 2

BAHAMAS REEF FISH (22): BLACK GROUPER

The Black Grouper is a large fish of the reefs found in the western Atlantic, particularly in the waters of Florida, Bahamas, Caribbean and the Gulf of Mexico. It is a solitary species that mostly prefers the shallow waters around coral reefs.

Black Grouper ©Virginia Cooper @ G B Scuba

Formerly plentiful, these groupers (like other grouper species) have moved from an IUCN listing of ‘Least Concern’ to ‘Near-Threatened’. They have 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. 

Black Grouper ©Melinda Riger @ G B Scuba copy

An adult black grouper’s diet consists of small fish and squid. Juveniles feed primarily on crustaceans. However, certain tiny reef fish are important to the species as ‘cleaners’. You can read about their significance by clicking CLEANING STATIONS Here are examples of two black groupers receiving attention at the same cleaning station. Both also seem to be giving a ride to REMORAS.

Grouper at cleaning station ©Melinda Riger @ G B Scuba copy

Note that this fish has an embedded hook and is trailing a line – one that ‘got away’Grouper, Black, at cleaning station (+ hook) ©Melinda Riger @ GB Scuba copy

Despite the name, black groupers are not all black. They have many shades from dark to olive-coloured to pale. I believe the two photos below are of a grouper known as Arthur, a favourite with divers and definitely off the menu… Black Grouper  ©Melinda Riger @ G B ScubaBlack Grouper 2 ©Melinda Riger @ G B Scuba

The tiny bright blue fish in the photo above are Blue Chromis, a regular accompaniment on any snorkel or dive on a reef. I like the colourful little Fairy Basslet in the next photoBlack Grouper © Melinda Riger @ G B Scuba copy

Now that the NASSAU GROUPER has been awarded a closed season to help maintain numbers, it will be interesting to see if the winter fishing ban is extended to the Black Grouper…

Black Grouper (Arthur) ©Virginia Cooper @ G B Scuba

RELATED POSTS

TIGER GROUPER

NASSAU GROUPER

Credits: all photos Virginia Cooper and Melinda Riger of Grand Bahama Scuba 

‘TAKEN TO THE CLEANERS’: REEF FISH & CLEANING STATIONS


Goby (Cleaning) © Melinda Riger @ G B Scuba copy

Cleaning Goby (Melinda Riger)

‘TAKEN TO THE CLEANERS’: REEF FISH & CLEANING STATIONS

A cleaning station is a place where fish and and other aquatic life congregate to be cleaned. This involves the removal of parasites both externally and internally, and is be performed by various creatures including, on the coral reefs of the Bahamas, cleaner shrimps and various species of cleaning fish such as wrasses and gobies. The process conveniently benefits both the cleaned and the cleaner.

Tiger Grouper being cleaned by Cleaner ShrimpsGrouper being cleaned ©Melinda Riger @ GB Scuba copy

Blue Parrotfish being cleaned (or tickled, from its expression) by a Cleaner Shrimp Blue Parrot Fish & Peterson Cleaner Shrimp ©Melinda Riger @ G B Scuba copy

  Black Grouper being cleaned by gobies – note the ones in its mouth Grouper at cleaning station ©Melinda Riger @ G B Scuba copy

Black Grouper at a Cleaning Station with gobies. Note the hook and line… Grouper, Black, at cleaning station (+ hook) ©Melinda Riger @ GB Scuba copy

Tiger Grouper being cleaned by GobiesTiger Grouper being cleaned ©Melinda Riger @G B Scuba copy

Gobies checking a hand for parasites….Cleaning Gobies copy

When a fish approaches a cleaning station it will open its mouth wide or position its body in such a way as to signal that it needs cleaning. The cleaner fish will then remove and eat the parasites from the skin, even swimming into the mouth and gills of the fish being cleaned.

“Clean me!” An amazing view of a Tiger Grouper at a CleaningStation with its gills wide openGrouper, Tiger - gills open at cleaning station ©Melinda Riger @GB Scuba copy

Grouper at a cleaning station over a spongeSponge : Fish Cleaning Station ©Melinda Riger @ G B Scuba copy

Remora clinging to a shark. For more on this unusual symbiotic relationship, click HERE383586_510314062323321_1002533913_n copy

 All photos: Melinda Riger of Grand Bahama Scuba, with thanks as ever