IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?


Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?

The waters of Abaco teem with myriads of fish that depend on the coral reefs for shelter and safety, for breeding, for growing up in, and for nourishment. Sea fans (or gorgonians, to use the technical name) are animals too. They may look like plants and stay rooted to the spot, but like anemones these ‘soft corals’ are creatures of the reef and essential indicators of its health.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

At the moment it can still be said that the static (‘sessile’) members of the Abaco reef community are relatively unscathed by the impact of (and I don’t want to get into any arguments here) whatever causes mass bleaching and the death of reefs elsewhere in the world.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)  Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

The purple sea fan Gorgonia ventalina (classified by Linnaeus in 1785) is one of the most common species of sea fan, and a spectacular one at that. The main branches are linked by a lattice of smaller branches. Below the ‘skin’ is a skeleton made of calcite compounded with a form of collagen. 

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Sea fans are filter-feeders, and have polyps with eight tiny tentacles that catch plankton as it drifts past. They develop so that their orientation is across the prevailing current. This maximises the water passing by and consequently the supply of food as the fans gently wave in the flow.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)  Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Gorgonians have a chemical defense mechanism that protects against potential troublemakers. The main effect is to make themselves unpleasant to nibble or uproot.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One species impervious to this deterrent is the fascinating FLAMINGO TONGUE SNAIL (more of which quite soon). Other ‘safe’ species include the fireworm and BUTTERFLYFISHES.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

One benefit of sea fans to mankind is that their defensive chemicals have been discovered to provide the basis for drug research and development. It’s tempting to say that by way of gratitude, we pollute the waters they need for their very existence. So, consider it said…

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)    Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

All the photos featured are by courtesy of Capt. Keith and Melinda Rogers of the well-known local scuba dive and snorkel centre DIVE ABACO, located in central Marsh Harbour. As prime enablers of reef exploration in Abaco waters, it can truly be said that they too have plenty of fans.

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

Credits: Keith and Melinda Rogers; Dive Abaco @DiveAbaco, Marsh Harbour, The Bahamas ** The answer to the questions in the Title is… it’s both!

Purple Sea Fans, Abaco, Bahamas (Dive Abaco / Keith & Melinda Rogers)

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

LETTUCE SEA SLUGS: SOLAR POWERED ‘CRISPY BLISSFUL HEAVEN’


Lettuce Sea Slug, Bahamas (Melinda Riger / G B Scuba)

LETTUCE SEA SLUGS: SOLAR POWERED ‘CRISPY BLISSFUL HEAVEN’

The Lettuce Sea Slug Elysia crispata (transl. ‘Crispy Blissful Heaven’) was No.3 in the ‘WTF’ ‘What’s That Fish’ series (despite not actually being a fish at all). It is not by any means the weirdest creature featured so far but it is nonetheless an animal whose appearance excites curiosity. Unless you see one moving, it could easily be mistaken for a plant. Maybe even lettuce. It is in fact a SACOGLOSSAN.

Lettuce Sea Slug, Bahamas (Melinda Riger / G B Scuba)

The name ‘sacoglossan’ literally means ‘sap-sucker’. This group (or ‘clade’) comprises small gastropod mollusks that ingest the cellular content of algae (which isn’t really sap).

WHY WOULD THEY DO THAT?

Because they are… SOLAR POWERED slugs

Lettuce Sea Slug, Bahamas (Melinda Riger / G B Scuba)

WHAAAAA…..?

As I mentioned when I last visited these remarkable creatures, this isn’t a technical forum and too much science hurts my head. This species primarily lives off algae. May I give you the word KLEPTOPLASTY to drop lightly into your conversation? In a couple of sentences, algae / algal content is eaten but only partially digested. Certain elements are stored to produce photosynthesis by which light is converted to energy (cf plants) and the slug can in effect live and move around without food. You could entertain your neighbour at dinner (or maybe on public transport, why not?) by summarising the process as “chloroplast symbiosis”. Meanwhile, I’m fetching a beer. Two beers.

Lettuce Sea Slug, Bahamas (Melinda Riger / G B Scuba)

HOW DO THEY REPRODUCE?

This topic doesn’t seem to have excited much investigative interest, and there’s not much specific information about it. What there is sounds unnecessarily complicated, so I am just going to say authoritatively ‘they do it like many other slug species’ and hope that covers it. The pair shown below may be exploring the possibilities, or at least trying to work out which end is which. One is easy to tell, but the other? Time to make our excuses and leave…

Elysia_crispata_(Lettuce_Sea_Slug_pair) Nick Hobgood

HOW FAST, EXACTLY, DOES A LETTUCE SEA SLUG MOVE?

This rather beautiful video from ‘CORAL MORPHOLOGIC STUDIO’ will reveal all. You’ll soon see that progress is very slow. I recommend watching the first 30 seconds and you’ll get the idea. If you choose to persist, you will see the slug sort of turn and move off to the left.

DO SAY:        What an intriguing creature. It’s a true wonder of marine nature.

DON’T SAY:  Any good in a mixed salad?

Lettuce Sea Slug, Bahamas (Melinda Riger / G B Scuba)

Credits: Melinda @ Grand Bahama Scuba, Nick Hobgood, Coral Morphologic Studio, Laszlo Ilyes wiki

Lettuce Sea Slug (Laszlo Ilyes)

QUEEN ANGELFISH: BAHAMAS REEF FISH (46)


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

QUEEN ANGELFISH: BAHAMAS REEF FISH (46)

The Queen Angelfish Holacanthus ciliarisis is without doubt one of the most beautiful of all reef fishes in the Bahamas – and the competition is very strong. I have posted about them before, but to my surprise not for nearly 5 years. Too long: here are some much more recent photographs of adults and cute juveniles.

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

The bright colours, the pouty expressions, the appealing poses – these fish are true Beauty Queens. And helpfully, they are unlikely to be mistaken for any other fish species.

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

TEENAGE QUEEN ANGELFISHQueen Angelfish (Juv), Bahamas (Melinda Riger / Grand Bahama Scuba)

JUVENILE QUEEN ANGELFISHQueen Angelfish (Juvenile), Bahamas (Melinda Riger / Grand Bahama Scuba) Queen Angelfish (Juvenile), Bahamas (Melinda Riger / Grand Bahama Scuba)

Photo Credit: ©Melinda Riger (Grand Bahama Scuba), with thanks as ever

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

CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS


Pederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS 

Pederson’s Shrimps Ancylomenes pedersoni (also known locally as Peterson’s shrimps), are one of several species of cleaner shrimp found in The Bahamas and more generally in the Caribbean seas. The species was named in 1958 by a multifaceted medico-oceanologist-zoologist Fenner A. Chace. He seems to have specialised in shrimps, finding distinct and differing species and naming them (not unreasonably) after himself (chacei);or colleagues and people he knew / admired; and in one case his wife. Mr Pederson was among them.

Pederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

This tiny transparent creature with its vivid blue / purple markings and straggling pale antennae is unmistakeable, and helpfully cannot be confused with any other locally found shrimp species. Here’s an idea of its size, compared with a human finger and a blue parrotfish.

Pederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

WHERE DO THESE SHRIMPS LIVE?

Their preferred home is… and it’s certainly a left field choice among sea creatures… in amongst the stinging tentacles of certain sea anemones. Not only do they not get stung, but of course they are well-protected by the defensive pain that their hosts can inflict. They are usually found singly or in pairs, but sometimes a whole colony may inhabit the same anemone.

SO EXPLAIN HOW THEY DON’T GET STUNG

Ok. The shrimps gradually build up a kind of resistance by pressing their bodies and antennae against the tentacles of the host anemone for increasing lengths of time, until they become immune. It’s like one of those kids’ electric buzzer / rheostat machines. Or a TENS machine (for those who know about backache).

 IS THERE A DOWNSIDE TO ALL THIS?

Yes indeed. If a shrimp moves away from its host for a few days, it has to start the process of immunisation all over again. So presumably they tend to stay home-lovin’.

Home sweet home for the Pederson shrimpsPederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

SOMETHING ABOUT THE CLEANING, PLEASE

These shrimps offer ‘cleaning services’ to passing fish. When on duty, as it were, they wave their antennae vigorously to attract attention. A fish being cleaned will remain stationary and passive while external parasites and dead skin are removed. Many fish will open their mouths and gill covers for internal cleaning, with the tacit agreement that the cleaner will not become a snack. Shrimps often work in conjunction with small cleaner fish such as some species of goby and wrasse – see the links below for more on this topic, with copious images…

Pederson's Cleaning Shrimp, Bahamas (Melinda Riger, GB Scuba)

RELATED POSTS

CLEANING STATIONS

CLEANER FISH

Credits: all photos by Melinda Riger / Grand Bahama Scuba

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN


Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN

Hawksbills on their own, nosing around the colourful coral reefs of the Bahamas, are a beautiful sight. I don’t want to overdo the religious tendency of the title, but they are indeed wonderful to behold. Add FRENCH ANGELFISH and a QUEEN ANGELFISH and it’s as close to perfection as a reef scene gets. Click on the links above for more pictures and details about the two angelfish species seen here with the turtle. As ever, Melinda Riger was ready with her camera to capture these great images.

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba) Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

This astonishing photo was of course achieved by carefully balancing a GoPro on the turtle’s back, wrapping duct tape around it, and pressing ‘go’ (camera and turtle simultaneously). **

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

** This is not true. It’s just a cleverly shot turtle’s-eye view as it forages on the reef

This short video shot by Melinda’s husband Fred of a turtle ‘loving’ the camera is one of those wildlife events that cannot be predicted… but when it happens, it’s frankly a bit of a scoop.

OPTIONAL MUSICAL DIGRESSION

As I was writing this, an earworm started up and grew insidiously in both ears and then inside my head… the dread words “Elenore, gee I think you’re swell”. Followed by “so happy together…”. And then “she’d rather be with me…” Yes, I’ve now got TURTLES in my head, the (?long-and-hitherto-forgotten) band from the second half of the 60’s, with their cheery anodyne soppy-poppy love songs. And dammit, they’ve stuck… Here’s a reminder for those whose memory I have jogged. For anyone under, say, 75, step away from this area. Nothing to hear here.

Hawksbill Turtle & Angelfish (Melinda Riger / Grand Bahama Scuba)

Credits: Grand Bahama Scuba: all photos – Melinda Riger & video – Fred Riger; Turtle music – someone else’s music collection, not mine, honestly… (oh dear another lie I am afraid – cred gone)