OCTOPUS’S GARDEN (TAKE 9) IN THE BAHAMAS


Octopus (Melinda Riger - Grand Bahama Scuba)

OCTOPUS’S GARDEN (TAKE 9) IN THE BAHAMAS

We are back again under the sea, warm below the storm, with an eight-limbed companion in its little hideaway beneath the waves.

Octopus (Melinda Riger - Grand Bahama Scuba)

It’s impossible to imagine anyone failing to engage with these extraordinary, intelligent creatures as they move around the reef. Except for octopodophobes, I suppose. I’ve written about octopuses quite a lot, yet each time I get to look at a new batch of images, I feel strangely elated that such a intricate, complex animal can exist. 

Octopus (Melinda Riger - Grand Bahama Scuba)

While examining the photo above, I took a closer look bottom left at the small dark shape. Yes my friends, it is (as you feared) a squished-looking seahorse, 

Octopus (Melinda Riger - Grand Bahama Scuba)

The kind of image a Scottish bagpiper should avoid seeingOctopus (Melinda Riger - Grand Bahama Scuba)

OPTIONAL MUSICAL DIGRESSION

With octopus posts I sometimes (rather cornily, I know) feature the Beatles’ great tribute to the species, as voiced with a delicacy that only Ringo was capable of. There’s some fun to be had from the multi-bonus-track retreads currently so popular. These ‘extra features’ include alternative mixes, live versions and – most egregious of all except for the most committed – ‘Takes’. These are the musical equivalent of a Picasso drawing that he botched or spilt his wine over and chucked in the bin, from which his agent faithfully rescued it (it’s now in MOMA…)

You might enjoy OG Take 9, though, for the chit chat and Ringo’s endearingly off-key moments.

All fabulous photos by Melinda Riger, Grand Bahama Scuba taken a few days ago

Octopus (Melinda Riger - Grand Bahama Scuba)

 

YELLOWTAIL PARROTFISH: BAHAMAS REEF FISH (54)


Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

YELLOWTAIL (REDFIN) PARROTFISH: BAHAMAS REEF FISH (54)

The yellowtail parrotfish (sometimes known as a redfin) is one of around half-a-dozen kinds of parrotfish found among the coral reefs of the Bahamas, and sometimes in seagrass areas. There are many other related species worldwide (about 80). Parrotfish are among the most important fishes on the reef because they play a major role in BIOEROSION , a vital process for the health of the reef.

Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

A. FEEDING & BEACH BUILDING

  • Their dental arrangements – a mouthful of meshing teeth – form the characteristic ‘beak’
  • Primarily herbivores but also snack on small creatures, organisms, or even molluscs
  • As they feed on their favourite algae, their teeth grind up the coral which they ingest
  • They digest the coral & excrete it as sand, becoming a component of your favourite beach
  • The teeth grow continuously, replacing ones worn away by grinding coral as they graze
  • They are a vital species in preventing algae from choking coral: essential reef cleaners

Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

B. PARROTFISH: PERSONAL INFORMATION

  • Some secrete a protective mucous cocoon to sleep in or as concealment from predators
  • Mucous also helps to heal damage, repel parasites, & protect them from UV light
  • As they develop from the juvenile stage, most species change colour significantly
  • In some species, juveniles change colour temporarily for protective purposes
  • These are “sequential hermaphrodites”, turning from female to male (‘protogyny’)
  • Single males tend to have several lady friends, and aggressively defend their love rights
  • Parrotfish are PELAGIC SPAWNERS. Females release many tiny buoyant eggs into the water
  • The eggs float freely then eventually sink to the coral until they hatch
  • Unlike almost all other fishes, they use their pectoral fins to propel themselves
  • Feeding behaviour / dietary requirements make them (thankfully) unsuitable for aquariums (or aquaria, if you prefer)

Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

WHAT WAS THAT ABOUT CHANGING SEX?

  • Parrotfish may undergo sex reversal in which developing female fish become males
  • Parrotfish born male remain male throughout their lives (“primary males”)
  • Female-born fish may change sex & colour to become male (“secondary males”)
  • Secondary males are fertile and generally mate with a single female
  • Females that stay female live in harems protected by a dominant “supermale” BUT…
  • …if the supermale dies, the largest female in the group changes sex to become male…
  • …AND amazingly adopts the coloration of the supermale (best ‘astounding fact’ of all)

Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

ARE PARROTFISH EDIBLE? JUST ASKING…

  • Parrotfish skin is very tough but their flesh is soft and degenerates quickly
  • Some species (eg blue parrotfish) carry ciguatera toxins – to be avoided
  • They are not considered a fishing target in Bahamas, nor a food-fish
  • Parrotfish are eaten elsewhere in the world however, for example Jamaica (cooked)
  • In Hawaii they are eaten raw – at one time they were reserved for royalty

VIDEO LINK: PARROTFISH POOP

Credits: Melinda Rogers / Dive Abaco for her great illustrative images. All photographs were taken on the reefs of Abaco, before the devastation and destruction of Hurricane Dorian last September; Florida Museum to cross-check facts; VIDEO – Scientific American

Yellowtail (Redfin) Parrotfish (Melinda Rogers / Dive Abaco)

AN OCTOPUS’S GARDEN, BAHAMAS


Octopus on coral reef, Bahamas (Melinda Riger / GB Scuba)

AN OCTOPUS’S GARDEN, BAHAMAS

Most of us, from time to time, might like to be under the sea, warm below the storm, swimming about the coral that lies beneath the ocean waves. An undeniably idyllic experience that is perfected by the presence of an octopus and the notional garden he lives in. Enough to make any person shout and swim about – and quite excessively at that.

Octopus on the coral reef, Bahamas (Melinda Riger / GB Scuba)

The extra ingredient here is that these photographs were taken on the reef off the southern coast of Grand Bahama last week, less than 2 months after the island (along with Abaco) was smashed up by Hurricane Dorian. Thankfully, Grand Bahama Scuba has been able to return to relative normality and run diving trips again. Moreover, fears for the reefs have proved relatively unfounded. These images suggest little damage from the massive storm. The Abaco reefs have not yet been able to be assessed in any detail.

Octopus on the coral reef, Bahamas (Melinda Riger / GB Scuba)

The feature creature here was observed and photographed as it took it a octopodic wander round the reef. The vivid small fishes are out and about. The reef and its static (technically ‘sessile’) life forms –  corals, anemones and sponges –  look in good order. The octopus takes a pause to assess its surroundings before moving on to another part of the reef.

Octopus on the coral reef, Bahamas (Melinda Riger / GB Scuba)

THE PLURAL(S) OF OCTOPUS REVISITED

A long time ago I wrote a quasi-learned disquisition on the correct plural for the octopus. There were at least 3 possibilities derived from Greek and Latin, all arguable but none so sensible or normal-sounding as ‘octopuses‘. The other 2 are octopi and octopodes. If you want the bother with the details check out THE PLURAL OF OCTOPUS

There’s an aspect I missed then, through rank ignorance I’d say: I didn’t check the details of the Scientific Classification. Now that I am more ‘Linnaeus-woke’, I have two further plural candidates with impeccable credentials. Octopuses are cephalpods (‘headfeet’) of the Order Octopoda and the Family Octopodidae. These names have existed since naturalist GEORGES CUVIER (he of the beaked whale found in Bahamas waters) classified them thus in 1797.  

RH ADVICE stick with ‘octopuses’ and (a) you won’t be wrong (b) you won’t get into an un-winnable argument with a pedant and (3) you won’t sound pretentious

Octopus on the coral reef, Bahamas (Melinda Riger / GB Scuba)

OPTIONAL MUSICAL DIGRESSION

Whether you are 9 or 90, you can never have too much of this one. If you are somewhere in the middle – or having Ringo Starr free-styling vocals doesn’t appeal – you can. Step back from the vid.

All fabulous photos by Melinda Riger, Grand Bahama Scuba, Nov 2019

Octopus on the coral reef, Bahamas (Melinda Riger / GB Scuba)

 

 

 

PEACOCK FLOUNDERS REVISITED: NOW YOU SEE THEM…


Peacock Flounder (Melinda Riger / G B Scuba)

        PEACOCK FLOUNDERS (Part Deux)

MASTERS OF SUBAQUATIC CAMOUFLAGE

I featured the extraordinary, colour-transforming PEACOCK FLOUNDER Bothus lunatus about 3 years ago in the Bahamas Reef Fish series (No. 21 I think). These really are remarkable creatures, and I am pleased to be able to show some more wonderful illustrative photos. 

Peacock Flounder (Melinda Riger / G B Scuba)

ROVING EYES

In the fish shown here, you’ll see that – surprisingly – both eyes are on the upperside of the fish, above the rather grumpy mouth, whereas the head is horizontal to the ocean floor. Oddest of all, juveniles are constructed conventionally with bilateral eyes, and look like ‘normal’ fish rather than flatfish.

Peacock Flounder (Melinda Rogers / Dive Abaco)

As the fish matures, in some magic way the mechanics of which I can only guess at**, the right eye grows round to the topside and the flounder transforms from a ‘vertical’ fish to a flatfish. For this reason, the PF is known as a ‘lefteye’ flounder. Maybe in other flounder species in the world – the southern hemisphere maybe? – the eye that moves round to the upperside is the left eye.

Peacock Flounder (Virginia Cooper / G B Scuba)

The eyes of this fish have another special trick up their sleeves (so to speak). They operate completely independently. Thus the creature can look left and right, or forwards and backwards, simultaneously. It’s an excellent system for detecting predators coming from any angle. It’s a superpower we might all benefit from.

Peacock Flounder (Melinda Rogers / Dive Abaco)

DO THEY HAVE ANY OTHER TRICKS WE SHOULD KNOW ABOUT?

Yes they do indeed. If you have been admiring the fish shown so far, you’ll have noticed that the colour of each one differs from the others. In addition to the predator-protection that the eyes provide, the peacock flounder can make itself (near) invisible. They can rapidly change colour to match their surroundings. There are 3 reasons for this: to avoid / confuse predators; to conceal themselves on the sea-floor to catch passing prey; and, as dive expert Fred Riger has pointed out, “the male peacock flounder can, and does greatly intensify his colours to declare territory and attract females. When doing this the males will also signal with the left pectoral fin, sticking it straight up and waving it around.” 

The same fish, photographed over several minutes as it moves over the ocean floorPeacock Flounder (Wiki)

Matching the background happens as the fish swims, and in a few seconds. When they rest on the sea-floor, the camouflage may even become total. In #4 above you can just about make out the eyes. The whole effect is known as ‘cryptic coloration’ or CRYPSIS. In contrast, the image below shows just how adaptable the transformation can be. Note how the fish can even mimic the pinkish tinge of the sand perfectly. If threatened, the fish will bury itself in the sand, with just its eyes showing.

Peacock Flounder (Melinda Rogers / Dive Abaco)

HOW DO THEY MANAGE TO CHANGE COLOUR IN SECONDS?

It’s complicated! A simple answer is: a mix of hormones, pigment-cells and vision, all coordinating rapidly. The colour change works in two ways: pigments are selectively released to the skin cells; and other pignments can be selectively suppressed. An analogy might be image manipulation using variations in brightness, saturation etc. Not convinced? Then watch this short video and prepare to be impressed. Astonished, even.

WHAT IF A FLOUNDER CAN’T SEE CLEARLY FOR SOME REASON?

As with many (all?) superpowers, there is usually some kryptonite-style flaw. A flounder with a damaged eye, or one temporarily covered (by sand, for example) will have difficulty in changing colour – possibly at all, or at any rate with the swiftness it needs to have. 

Peacock Flounder (Melinda Riger / G B Scuba)

THESE SIDEWAYS FISH – HOW DO THEY… YOU KNOW…?

Take a look at the fish above with its top fin raised. It’s a ‘ready’ signal in a harem. Male flounders have a defined and defended territory within which live up to 6 females – a so-called ‘harem.’ I can do no better than borrow the description of the rituals from an article derived from scientific papers by Konstantinou, 1994Miller, et al., 1991 in the website animaldiversity.org/…ounts/Bothus_lunatus To which I can only add, ’15 seconds, eh?’

Peacock Flounder (Melinda Riger / G B Scuba)

“Mating activities usually begin just before dusk. At this time, a male and a female approach each other with the ocular pectoral fin erect. The two fish arch their backs and touch snouts. After this interaction the female swims away, and the male sometimes follows, approaching the female again from the left side. At this point the male pectoral fin is erect and the female pectoral fin moves up and down, possibly signalling willingness to mate. The male then positions himself underneath the female and mating begins. This process consists of a mating rise, during which the female and male rise in the water column together. On average, these rises last about 15 seconds. At the highest point of this rise, usually around 2 m above the substrate, gametes from both fish are simultaneously released, producing a cloud of sperm and eggs. Once the couple returns from the rise, the male “checks” to make sure mating was successful, and the pair separates quickly, swimming away from each other in opposite directions. Not all mating rises are successful, and the process of “checking” is thus important. The exact purpose of the mating rise in these flounders unknown; possible reasons for rising include better dispersal of gametes and predator avoidance.” 

Peacock Flounder – Kim Rody ArtPeacock Flounder (Kim Rody Art))

**This may in fact be through sheer laziness

Credits: Melinda Riger & Virginia Cooper / Grand Bahama Scuba; Melinda Rogers / Dive Abaco; Adam Rees / Scuba Works; Kim Rody; animaldiversity.org; magpie pickings and other credits in the text

Peacock Flounder (Melinda Riger / G B Scuba)

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS


Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

Painted Tunicates Clavina picta are one of several species of tunicate ‘sea-squirts’ found in Bahamas and Caribbean waters. These creatures with their translucent bodies are usually found clustered together, sometimes in very large groups. One reason for this is that they are ‘sessile’, unable to move from where they have taken root on the coral.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

HOW DO THEY FEED?

Like most if not all sea squirts, tunicates are filter feeders. Their structure is simple, and enables them to draw water into their body cavity. In fact they have 2 openings, an ‘oral siphon’ to suck in water; and an exit called the ‘atrial siphon’. Tiny particles of food (e.g. plankton) are separated internally from the water by means of a tiny organ (‘branchial basket’) like a sieve. The water is then expelled. 

Diagram of adult solitary tunicate

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

WHAT DOES ‘TUNICATE’ MEAN?

The creatures have a flexible protective covering referred to as a ‘tunic’. ‘Coveringates’ didn’t really work as a name, so the tunic aspect became the name. 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

IF THEY CAN’T MOVE, HOW DO THEY… (erm…) REPRODUCE?

Tunicates are broadly speaking asexual. Once a colony has become attached to corals or sponges, they are able to ‘bud’, ie to produce clones to join the colony. These are like tiny tadpoles and their first task is to settle and attach themselves to something suitable – for life – using a sticky secretion. Apparently they do this head first, then in effect turn themselves upside down as they develop the internal bits and pieces they need for adult life. The colony grows because (*speculation alert*) the most obvious place for the ‘tadpoles’ to take root is presumably in the immediate area they were formed.

 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

Some types of tunicate contain particular chemicals that are related to those used to combat some forms of cancer and a number of viruses. So they have a potential use in medical treatments, in particular in helping to repair tissue damage.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

Credits: all fabulous close-up shots by Melinda Riger / Grand Bahama Scuba; diagram from depts.washington.edu; magpie pickings with a particular mention of an article by Sara MacSorley

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

 

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN


Hawksbill Turtle Bahamas (Melinda Riger / G B Scuba)

HAWKSBILL TURTLES: ENJOY THEM WHILE YOU CAN

Pliny the Elder (CE 23–79) was one of the earliest naturalists, besides being a philosopher, author and military commander. He wrote Naturalis Historia (Natural History), a wide-ranging work that became a model for later scholarly works, including forms of Encyclopedia. And, as he so nearly wrote, ‘si non amas testudines, vacua anima tua est’ (he that loves not sea turtles, has an empty mind)*

Hawksbill turtle grazing while a French angelfish looks onHawksbill Turtle with French Angelfish, Bahamas (Melinda Riger / G B Scuba)

There can be few better ways to start the New Year than with some gorgeous Hawksbill Turtles  Eretmochelys imbricata, plus a sprinkling of turtle facts to give 2019 a good push into orbit. Fortunately still available in Bahamas waters, the continued existence of Hawksbills is under serious threat. Make the most of your opportunities.

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

  • Guesstimates of the world Hawksbill Turtle population suggest that there are 5 main groups in the oceans, with few enough individuals – especially breeding females – to warrant an IUCN listing of the species as critically endangered
  • I doubt that many will forget that the next IUCN category is… extinct (≠ ‘fun fact’)
  • The largest Hawksbill colony in the world nests on an island in Queensland Australia
  • Turtles leave the sea to lay eggs in a hole dug on the beach, before returning to the sea.
  • The eggs hatch after c60 days… the turtlings emerge and are then on their own
  • Hawksbills are omnivorous, mainly eating sponges (& immune from sponge toxins)
  • They also eat sea anemones, mollusks, and jellyfish
  • Their grazing lifestyle is an important component of a healthy coral reef ecosystem

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

  • Though their shells are hard, Hawksbills are prey for sharks, crocodiles, octopuses and the biggest predator of all, humans“.
  • Despite international Hawkbill protection and conservation measures, they continue to be illegally hunted – including, in some places, for food.
  • Their lovely shells – tortoiseshell – are illegally traded for use for ornaments and jewellery
  • Japan makes its own rules (as with whales) for traditional & no doubt research purposes
  • ‘Tortoiseshell’ is the illegal item most frequently confiscated by custom officials
  • Reef and beach degradation, development, light pollution (confuses the baby turtles trying to paddle to the sea), ocean pollution / marine debris, and illegal practices are among the greatest dangers to the survival of the species. All are caused, directly or indirectly, by you and indeed me

Hawksbill T ©Melinda Riger + G B Scuba copy.jpg

Credits: wonderful photos by Melinda Riger / Grand Bahama Scuba (1, 2, 5) & Adam Rees / Scuba Works (3, 4, 6); Widecast; Nature Conservancy; OneKind Planet

Hawksbill Turtle Bahamas (Adam Rees / Scuba Works)

* Do not believe this – I invented it. The quote that props up the pretentious stuff, that is – all the rest is true…

BAHAMAS REEF FISH (48): SCHOOLMASTER SNAPPER


Schoolmaster Snapper (Melinda Riger @ G B Scuba)

BAHAMAS REEF FISH (48): SCHOOLMASTER SNAPPER

November 1st already, and the first time I am prepared to consider the possibility of the onset of Christmas, with its attendant joys yet complications… Meanwhile, I thought I might have run out of types of reef fish to feature in this series long before I got to 50. Yet here we are, two short of that target, with a species of snapper I haven’t even mentioned before. I am (frankly) a rather feeble swimmer, and do not possess a viable underwater camera. So there’s no way I could show these denizens of the not-especially-deep without heavy reliance on others, in particular the outstanding photos of diver Melinda Riger of Grand Bahama Scuba; and the memorable ones from Adam Rees of Scuba Works that include some of the more obscure species that appear in my WTF? (What’s That Fish) series. 

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

The schoolmaster snapper (Lutjanus apodus) lives among the coral reefs and mangroves of the Caribbean and further north to the northern Bahamas and Florida. Generally they are quite small, not much more than 12- 18 inches. They tend to hang out in ‘schools’, which several sources suggest as the reason they got their common name. But schoolmasters don’t really move around in large groups, do they? It’s school pupils that do that, but ‘Pupil Snapper’ wouldn’t cut it as a fish name I guess.

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

10 SCHOOLMASTER SNAPPER FACTS TO PONDER

  • One pair of upper teeth are so large they protrude when the fish shuts its mouth
  • Their side scales are so arranged that diamond shapes are produced
  • There’s plenty to learn about their fin arrangements, but not necessarily to remember
  • Their jaws don’t open very wide, so their prey tends to be quite small
  • Unlike fish that change sex as they grow, these ones retain their birth gender for life
  • When they spawn they produce their gametes simultaneously, and swim away
  • The fertilised eggs sink to the bottom, where they have to take their chances
  • Though small, they are good to eat and are fished for recreation and commercially
  • Regionally there are specific regulations as to catch length & limits, hook type, bait etc
  • Like all snappers and many other fish species, these fish are associated with ciguatera

Schoolmaster Snapper (Melinda Riger @ G B Scuba)

RECIPES

For those who enjoy cooking (whatever that is), you probably know exactly how you like to cook your snappers. For anyone else, here’s a site that proposes several different ways to cook them, with helpful tips. These seem to apply to all snapper species, most of which are available free in the Bahamas. http://www.allfishingbuy.com/Fish-Recipes/Snapper-Recepies.htm

My favourite schoolmaster snapper photo of those featured hereSchoolmaster Snapper (Melinda Riger @ G B Scuba)

POSSIBLE MEDICAL BENEFITS FROM EATING SNAPPERS

These are alleged to include (except when fried): protection against certain types of stroke, reduction of heart arrhythmia, and defence against certain types of cancer. Don’t take my word for it, though. And definitely don’t rely on a snapper-based diet regime. I think the most that can safely be said is that eating snapper will do you no harm (except when fried) and may conceivably have a marginal benefit on health along with a balanced diet, exercise, minimal alcohol intake and all the routines that we strictly adhere to for a healthy life. In our dreams, anyway.

Schoolmaster Snapper (Albert Kok)

Credits: All great pics by Melinda Riger / GB Scuba except #6 Albert Kok; range map, Wiki. Magpie pickings.

Schoolmaster Snapper (Melinda Riger @ G B Scuba)