“CLINGING TO THE WRECKAGE”: BAHAMAS CLINGING CRABS


Clinging crab in smoke stack on Theo's Wreck ©Melinda Riger @ G B Scuba

“CLINGING TO THE WRECKAGE”: BAHAMAS CLINGING CRABS

The Clinging Crab Mithrax spinosissimus answers to a number of names: West Indian spider crab, channel clinging crab, reef or spiny spider crab, or coral crab. It is found throughout the waters of South Florida and the Caribbean. Clinging Crab ©Melinda Riger @ G B Scuba copy

These are crabs of the reef, or indeed of the wrecks that may be found around reefs. Some of the crabs in this post have chosen wrecks as their home – in the header image the crab is living inside the smoke stack of ‘Theo’s Wreck’, Grand Bahama.Clinging Crab ©Melinda Riger @ GB Scuba

The clinging crab is believed to be omniverous, its main diet being algae and carrion. They can grow to 2 kg, and it is the largest species of reef crab found in the Caribbean.Clinging Crab © Melinda Riger @ G B Scuba

The clinging crab / West Indian spider crab is (apparently) not commercially harvested for its meat. However, it is said to be delicious. Any views on this welcome in the comments section! If you want to know more about how to prepare (“a real challenge”) and cook a spider crab, check out this LINK

Clinging Crab ©Melinda Riger @ G B Scuba

Life on the reef can be dangerous. This crab has lost some legs: its clinging powers are somewhat curtailed…Clinging Crab (legs missing) ©Melinda Riger @ G B Scuba

This guy has some missing parts, but seems quite laid back about it…Clinging Crab, Bahamas (Melinda Riger, G B Scuba)

Credits: Melinda Riger of Grand Bahama Scuba (all photos); Tom Hunt, eco-chef (recipe)

“THE BUTTERBUN” (LONGSNOUT BUTTERFLYFISH): BAHAMAS REEF FISH (26)


Longnose : Longsnout Buttefly Fish ©Melinda Riger @ G B Scuba copy

“THE BUTTERBUN” (LONGSNOUT BUTTERFLYFISH)

BAHAMAS REEF FISH (26)

The Atlantic/ Caribbean Longsnout Butterflyfish Prognathodes aculeatus is sometimes known locally as the Longnose (not to be confused with the bright yellow Indo-Pacific Longnose Butterflyfish). The affectionate name for it is ‘Butterbun’. A more scientific name is ‘Poey’s Butterflyfish’, named for the man who first identified the species in 1841.

Mr Felipe Poey

Longnose : Longsnout Butterflyfish  © Melinda Riger @ GB Scuba copy
These little fish, 2 0r 3 inches long, are commonly found on reefs from Florida down to Venezuela. Unlike most butterflyfishes, they prefer deeper water and have been found at 200 ft; and they tend to be solitary rather than gregarious.
Longnose: Longsnout Butterflyfish ©Melinda Riger @ G B Scuba copyLongsnout Butterflyfish (www.whatsthatfish.com)
BUTTERBUN. THAT SUGGESTS THEY ARE PLUMP?

Longsnout Butterflyfish (π Florent's Reef Guide)NOPE!Longsnout Butterflyfish Prognathodes aculeatus (Wiki)

RELATED LINKS

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

Longnose : Longsnout Butterflyfish ©Melinda Riger @GB Scuba copy

Credits: Melinda Riger for her brilliant underwater images (as marked); plus What’s That Fish?, Florent’s Guide and good old Wiki…

WTF? (WHAT’S THAT FISH?) (5): THE FROGFISH


Frogfish (Adam Rees, Scuba Works)

WTF? (WHAT’S THAT FISH?) (5): THE FROGFISH

This ‘WTF?’ series started with a relatively conventional species, the REMORA. It has been getting progressively more bizarre. We moved onto an omnium gatherum of WEIRDO FISHES, then the remarkable LETTUCE SEA SLUG, and most recently the BATFISH. Time to ramp up the stakes: with many thanks to scuba expert Adam Rees for use permission for his terrific photos, I present… the FROGFISH.

Frogfish (Adam Rees, Scuba Works)

The frogfish is a kind of anglerfish found in almost all tropical and subtropical oceans and seas. There are about 50 different species worldwide, covering an astonishing range of strange appearances. They generally live on the sea floor around coral or rock reefs. In size they vary from tiny to about 15 inches long – although ‘long’ is a flexible concept because they are to an extent shape-changers in height and width.Frogfish (Adam Rees Scuba Works)

FROGFISH SUPERPOWERS YOU MAY WISH TO HAVE

  • INVISIBILITY CLOAK . Frogfish are masters of disguise and camouflage. This enables them to catch their prey with minimal effort and also to avoid predators. Their camouflage methods – broadly known as ‘aggressive mimicry’ – include
    • Ability to change colour for days or even weeks to mimic their surroundings
    • Getting covered in algae and other organic matter that matches their habitat or
    • Looking inherently like a plump rock or in some cases, plant

Fear for the life of the spider crabFrogfish (Adam Rees, Scuba Works)

  • IRRESISTIBLE ATTRACTION (just like that nice Mr Grey)
    • A sort of frontal dorsal fin called an illicium to which is attached a
    • Lure called an esca which may mimic a worm, shrimp or small fish etc and which is
    • Retractable in many species and
    • Regenerates if it gets mislaid

The ‘dollop of cream’ thing is the esca. Note the characteristic large mouthFrogfish (Adam Rees, Scuba Works)

Spot the escaFrogfish (wiki)

  • BUOYANCY CONTROL & SHAPE-SHIFTING
    • Most frogfish have a ‘gas bladder’ to control their buoyancy.
    • Some species can change shape or even inflate themselves by sucking in quantities of water in a so-called defensive ‘threat display’.

frogfish-black

Frogfish (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

HOW DO FROGFISH REPRODUCE? 

Although not conventionally attractive creatures, frogfish clearly manage to reproduce. Little is known about the techniques in the wild, but one is probably ‘with care’, especially for a male frogfish who may not survive for long if he hangs around after fertilisation has taken place. It has been noted that females tend to select far smaller males to fertilise their huge numbers of eggs, perhaps for that very reason.

Frogfish (Adam Rees, Scuba Works)

FROGFISH FEEDING SKILLS – GOOD OR BAD?

When deploying the lure, potential prey that comes too close to that wide mouth stands no chance. A frogfish will strike in a fraction of a second. Frogfishes have voracious appetites for crustaceans, other fish, and even each other. I can do no better than borrow this vivid description of a feeding frogfish:

“When potential prey is first spotted, the frogfish follows it with its eyes. Then, when it approaches within roughly seven body-lengths, the frogfish begins to move its illicium in such a way that the esca mimics the motions of the animal it resembles. As the prey approaches, the frogfish slowly moves to prepare for its attack; sometimes this involves approaching the prey or “stalking” while sometimes it is simply adjusting its mouth angle. The catch itself is made by the sudden opening of the jaws, which enlarges the volume of the mouth cavity up to twelve-fold, pulling the prey into the mouth along with water. The attack can be as fast as 6 milliseconds. The water flows out through the gills, while the prey is swallowed and the oesophagus closed with a special muscle to keep the victim from escaping. In addition to expanding their mouths, frogfish can also expand their stomachs to swallow animals up to twice their size.

images

HOW DO FROGFISHES GET AROUND? SWIM? WALK? CRAWL?

Frogfishes do not in fact move around a great deal. Using their camo advantages, they prefer to lie on the sea floor and wait for prey to come to them. As mentioned in the quote above, they may slowly approach prey using their pectoral and pelvic fins to “walk” along the sea bottom. They can swim using their tail fin (or in some species by simple ‘jet propulsion’ by forcing water out of their gills) but rarely do so – they don’t feed on the move, and they are adapted to the sea floor environment where they food is readily available. However their “walking” ability is limited to short distances.

frogfish-anglerfisch

DO FROGFISH HAVE OTHER COLOUR SCHEMES?

Indeed they do. In stark contrast to the camo species, some frogfishes are highlighter bright. Here are two of my favourite photos by Adam that show this clearly. I’ve no idea if these are a male and female. I suspect they are different species. I think the brown one is a striated frogfish and the other is… a yellow frogfish. Some people keep these creatures in  aquaria, but apparently it is impossible to sex them, and they have to be kept on their own for everyone’s peace of mind…

Frogfish (Adam Rees Scuba Works) Frogfish (Adam Rees Scuba Works)

FROGFISH INFOGRAPHICS

frogfishFrogfish Infographic 'Monsters of the Deep'

FROGFISH VIDEOS

These two videos, from Lester Knutsen and Daan Van Wijk respectively, show some of the characteristics I have written about above. Both are short and both are fascinating.

To read more about frogfishes and for some fabulous photos I highly recommend the website FROGFISH.CH You can reach the main page(s) but the link seem to be broken so I have not been able to contact Teresa Zubi, whose site it is. She clearly has a sense of humour and uses a neat pair of gifs which I hope she won’t mind my using…

Credits: All main photos, Adam Rees  of Scuba Works with many thanks; wiki for ‘spot the esca’, red quote & basic info; videos Lester Knutsen & Daan Van Wijk; Teresa Zubi for website & gifs; infographics, authors u/k

Frogfish Tee Shirt

BRITTLE STARS: PRIMITIVE YET INCREDIBLY COMPLEX STARFISH


Brittle Star around a Tube Sponge ©Melinda Riger @ GB Scuba

BRITTLE STARS: PRIMITIVE YET INCREDIBLY COMPLEX STARFISH

BRITTLE STARS are closely related to starfish, and in particular to Basket Stars. They are commonly known as “serpent stars”, having 5 long, thin arms that may grow as long as 2 feet long. There are lots of different types of brittle star – at least 2000 – and they are found in every ocean on earth from the poles to the tropics. In Bahamian waters they a commonly found living on reefs.

Although these creatures look primitive, their structure, nervous systems, respiratory systems, digestive systems, sex lives and transportation methods are incredibly complex. Take it from me – I’ve just read about it all. So I’ve decided to pick a few aspects of these creatures to highlight rather than discuss the minutiae of their ossicles (tiny bones), madroporites (a sort of water filter / pressure balancer) and viscera.

You are most likely to see Brittle Stars clinging to coral or spongesSponge & Brittle Star ©Melinda Riger @GB Scuba

A DOZEN BRITTLE STAR FACTS TO PLAY WITH

  • The star has no eyes and no sense organs as we know them, but can detect light chemically; and (why would they need this?) sense smell through their ‘feet’… [Not a superpower I would prize, but still]
  • The mouth is on the underside of the central disc (‘body’) of 5 segments, each with a toothed jaw
  • The mouth is used both for ingestion and, putting it delicately, egestion. [Nor that superpower]
  • Stars eat tiny organisms suspended in the water or mini-worms, gathering them with their arms
  • If I have understood this, they breathe through their armpits, and can excrete from here also
  • The arms fit the main part with ball and socket joints, and are flexible in all directions
  • The genitals seem to be located in or between the armpits (lucky we are not descended from stars)
  • Stars readily regenerate lost arms until they lose the 5th – then they are in real trouble
  • This enables them to shed an arm in a predator attack, like a lizard its tail
  • Trials indicate that a jettisoned arm cannot regenerate from itself
  • They use only 4 arms to move along, with the fifth ‘steering’ out in front or trailing behind
  • Brittle Stars are inedible but non-toxic

Brittle Star on Green Rope Sponge ©Melinda Riger @ GB Scuba

Often, brittle stars will cling on inside a spongeBrittle Stars in sponge ©Melinda Riger @ GB Scuba

I quite liked this infographic from a source new to me, ‘Weird ‘n’ Wild Creatures Wikia’Brittle_Stars_front

Here is a great video from Neptune Canada of a brittle star fight on the ocean floor over the remains of a shrimp. If you watch the ones joining the fight, you will clearly see the locomotion method described above, with one limb pathfinding and the other four ‘walking’.

I’m not renowned for extreme sensitivity, so I feel no shame in showing mating brittle stars, courtesy of Channel Banks. It’s not exactly Lady Chatterley and Mellors, but the entwined arms are rather romantic, no?

Credits: all wonderful photos by Melinda Riger of Grand Bahama Scuba; BS infographic and viddys as credited

“ONE IS CALLED LUCY…”: SWIMMING WITH BAHAMAS SHARKS


Shark, Blacktip ©Melinda Riger @ G B Scuba copy 2

“ONE IS CALLED LUCY…”: SWIMMING WITH SHARKS

From time to time I wonder about the naming of animals. I know about the problems that can arise when people name their chickens Henny, Penny, Denny & Lenny, and the time comes to (please look away now). And how a slavering dog coming towards you (not on a lead) that the owner calls ‘Tyson’ or ‘Killer’ is possibly one to cross the street for. And that the owner of a cat called ‘The Reverend Wenceslas Muff’ (Sir Roy Strong, in fact) may not take kindly to you referring to it facetiously as ‘Puddy-tat’. But does it make things any better to know that the shark that is eyeballing you is called Lucy? I don’t know the names of the others, but I am sure they would all like to be introduced… Shark close-up ©Melinda Riger @ G B Scuba copyShark with remora ©Melinda Riger @ G B Scuba copyShark © Melinda Riger @ G B Scuba copy 2Shark ©Melinda Riger @ GB Scuba copy 2Shark Head ©Melinda Riger @ GB Scuba copy 2Shark 2 ©Melinda Riger @ G B Scuba copy 2Shark 4 ©Melinda Riger @ G B Scuba copyShark (pregant female) ©Melinda Riger @G B Scuba copy

REMORAS Some of the photos show a strange creature attached to the underside of the shark. For more info about these weird shark passengers, and some great images, click HERE

All the fabulous photographs above were taken by Melinda Riger and Virginia Cooper of Grand Bahama Scuba, on whom I rely entirely for subaqueous material, being a pathetic swimmer, a gnarly ancient, and a certified scaredy-cat (‘highly commended’). My thanks as always to them for use permission

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

CHERUBFISH (PYGMY ANGELFISH): BAHAMAS REEF FISH (23)


Cherubfish (Pygmy Angelfish) © Melinda Riger @ G B Scuba

 CHERUBFISH (PYGMY ANGELFISH): BAHAMAS REEF FISH (23)

Time for a bright little denizen of the not-so-deep. The Cherubfish Centropyge argi or pygmy angelfish is a very small (8cm) and distinctively coloured angelfish species. These fish are native to the Caribbean and Gulf of Mexico, and flicker round the coral reefs happily feeding as they go (see the video below to see how busily they forage). Or maybe they are just having a good time…

Cherubfish (rare) ©Melinda Riger @ G B Scuba

The Cherubfish is unsurprisingly a popular aquarium species. Don’t rush straight out and buy some though: a typical warning says “like other angel fish, they are not completely 100% reef-safe. Results vary among individual fish and tank qualities (size, feeding, tankmates, etc.), so caution is recommended when adding this fish to a coral tank“. You can read the whys and the wherefores HERE – sadly I lack the vibrant interest in aquaria to go into it myself…

Cherubfish Melinda Riger @ G B Scuba

Looking beyond Melinda’s lovely images of the species, I have found that these creatures will often show more yellow at the nose end. Here’s an example of a more two-tone Cherubfish in case you come across one. Cherubfish Centropyge argi  (Brian Gratwicke)

I mentioned that Cherubfish flicker around the reefs instead of proceeding serenely and in an orderly fashion.  Have a look at this short video to see what active little fish they are.

RELATED POSTS

GRAY ANGELFISH 1

GRAY ANGELFISH 2

QUEEN ANGELFISH 1

QUEEN ANGELFISH 2

DAMSELFISH

ROCK BEAUTY

Credits: all images Melinda Riger of Grand Bahama Scuba except the last, Brian Glanville