CLEANING UP IN THE BAHAMAS: PEDERSON SHRIMPS

August 29, 2017 by Rolling Harbour

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.

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.

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 shrimps Pederson'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…

CLEANING STATIONS

CLEANER FISH

Credits: all photos by Melinda Riger / Grand Bahama Scuba

BAHAMAS REEF FISH (38): SPOTFIN BUTTERFLYFISH

August 22, 2017 by Rolling Harbour

BAHAMAS REEF FISH (38): SPOTFIN BUTTERFLYFISH

Butterflyfishes are a large family of mainly colourful small fish somewhat like mini-angelfish. The spotfin butterflyfish (Chaetodon ocellatus) is one of several types of butterflyfish found in the western Atlantic Ocean; and one of half a dozen or so you are likely to see nosing around the coral reefs of the Bahamas.

The name ‘spotfin’ derives from the dark spot on the dorsal fin. At the front end, there is a distinctive black vertical stripe that passes right through the eye. Combined with the vivid colouring, predators are in theory confused or warned off. The spotfin’s superpower (on a modest scale) is that at night, a change of appearance occurs in adults. The dark patch on the dorsal fin increases in size, and dark bands appear on the body. This seems to be in order to provide further protection during the darker hours.

The spotfin above has an isopod attached to it, a type of crustacean with a segmented body. Primitive fossils of these creatures have been dated back some 3m years. Want to know want this one is up to? These things “are mostly external parasites of fish or crustaceans and feed on blood, having piercing and sucking mouthparts and clawed limbs adapted for clinging onto their hosts”.

Soldierfish photobombs a spotfin. Or maybe it’s vice versa?

Reading about this particular species of butterfly fish, I discovered that the spotfin “is very common and very hard to maintain in a tank” – as if the two facts are somehow connected. So might they be coarse or vulgar, and thus unsuitable companions for better bred and perhaps sensitive aquarium fish? As it turns out, it may be because they are vulnerable to predation, and so can coexist only with peaceable tank friends.

Spotfins are perfectly happy swimming upside down; and their party trick apparently is to rise to the surface and squirt a jet of water in the air. Sadly, I couldn’t come up with a photo of this…

LONGSNOUT BUTTERFLYFISH

REEF BUTTERFLYFISH

Credits: All fab photos by Melinda Riger / Grand Bahamas Scuba

ROCK BEAUTY: BAHAMAS REEF FISH (37)

July 28, 2017 by Rolling Harbour

ROCK BEAUTY: BAHAMAS REEF FISH (37)

The Rock Beauty Holacanthus tricolor is 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. They featured near the start of this series HERE, and a recent online search (for something else completely, as is often the way) reminded me to give them another swim round Rolling Harbour.

In addition to the hi-viz-and-eyeliner combo, the Beauty above has chosen a fetchingly cheeky pair of matching ISOPODS (crustacean parasites) to adorn its face – possibly the piscine equivalent of a tat…

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

WHAT DO JUVENILES LOOK LIKE?

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

NOTE Rock Beauties have no known relationship to Chrissie, Debbie, Lita, Stevie, Joanna, 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,Wiki

HAWKSBILL TURTLES + ANGELS = REEF HEAVEN

July 18, 2017 by Rolling Harbour

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.

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). **

** 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.

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)

BAHAMAS REEF FISH (36): REEF BUTTERFLYFISH

July 6, 2017 by Rolling Harbour

BAHAMAS REEF FISH (36): REEF BUTTERFLYFISH

Butterflyfishes come in several varieties in Bahamian waters; and there are more than 120 species worldwide. Not so long ago I wrote about the LONGSNOUT variety, also known as the “Butterbun”. Now it’s time to take a look at the Reef Butterfyfish.

In some ways butterflyfishes resemble small angelfishes – adult Reefs are just a few inches long. As the name suggests, these are creatures of the reefs, and of shallow waters. As one might expect, these colourful fish are popular for aquariums (or, strictly I suppose, aquaria).

Butterflyfishes have interesting spawning patterns. They release large numbers of buoyant eggs into the water. These become mixed in with plankton and suchlike, and float where the tides take them until they hatch. Then, most unusually, they go through a larval stage when they are covered by bony material, which they lose as they mature. This is known as an ‘armoured’ stage, which I can only assume is to provide protection to the tiny fry – perhaps by making them crunchy and unappetising. I’ve been trying to find a usable illustrative drawing, without success so far.

OPTIONAL MUSICAL DIGRESSION

In some parts of the world the butterflyfish is called a BORBOLETTA, which is Portugese for ‘butterfly’. It is also the title of Santana’s criminally underrated sixth album (1974). For sure it’s no 1st, Abraxas, 3rd or Caravanserai… but if you can tolerate the man’s move to ‘jazz-funk-fusion’ – maybe John McLaughlin had a hand in that – there is much to enjoy. There’s less searing guitar and there’s some strange ‘soundscape’ stuff that’s maybe not to everyone’s taste. But still – it stand up pretty well in comparison with some of the later Carlos creations where a certain tiresomeness began to creep in and some tracks are (IMVHO) not really listenable-to. Anyway, the recently released (2016) Santana IV is a welcome return to the good old days, and the good old team.

Here’s ‘Promise of a Fisherman’ – 8 minutes of Santana, from which you can judge the direction he’s taken by Album 6…

All photos by Melinda Riger of Grand Bahama Scuba – mainstay, with Adam Rees, of the underwater photos I use, what with me being a feeble swimmer and all. Tip o’ the Hat to Carlos, who I have even managed to see Live a couple of times.

REDSPOTTED HAWKFISH: BAHAMAS REEF FISH (35)

June 23, 2017 by Rolling Harbour

REDSPOTTED HAWKFISH: BAHAMAS REEF FISH (35)

The redspotted hawkfish (Amblycirrhitus pinos) is one of a number of species of hawkfishes found worldwide. This one is found on the sub-tropical and tropical reefs of the Western Atlantic, and is therefore a fish you might see when out snorkelling or (more likely) scuba-ing in the Bahamas. These are small creatures – adults are unlikely to exceed 4 inches in length.

There’s not a whole lot else to report about them. They have no medicinal superpowers, for example, nor wickedly toxic spines. A quick scroll through the highways and byways of the interweb reveals that redspotted hawkfish are considered (rightly, I think) to be attractive, tend to be shy, enjoy perching on coral ledges, and are generally benign, except to smaller fishes to which they may show aggression or – worse – an appetite.

As you might predict, these pretty little fish are popular in the aquarium trade, where on any view they should be kept safe from predators. But maybe captivity is a little limited in opportunities for travel and exploration. They can be bought for (I just checked) $29.99. Or else left alone on a reef to take their chances.

Photo Credits: Melinda Riger / Grand Bahama Scuba, with thanks as per…

JAW-DROPPING: A GROUP OF GROUPER(S)

June 6, 2017 by Rolling Harbour

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.

The 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.

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 wrasse

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….