HOGFISH: BAHAMAS REEF FISH (31)


Hogfish at cleaning station ©Melinda Riger @GB Scuba

HOGFISH: BAHAMAS REEF FISH (31)

Hogfish. Fisherman’s delight… getting ‘high on the hog’. This wrasse species Lachnolaimus maximus is a reef denizen, especially where gorgonians are found. It has the distinction of being the only known member of its genus, and because it is IUCN listed as vulnerable, there are strict regulations governing bag, size, and gear limits to protect the species from overfishing.

Hogfish ©Melinda Riger @ G B Scuba

The hogfish gets its name from its long ‘pig-like’ snout, coupled with its rootling behaviour on the sea floor for crustacean prey.

Hogfish ©Melinda Riger @ GB Scuba copy ed Hogfish foraging ©Melinda Riger @ GB Scuba

GENDER STUDIES: IT’S COMPLICATED

The hogfish is a sequential hermaphrodite, meaning it changes sex during different life stages. Juvenile hogfish are female, but mature into males at around 3 years old.

Hogfish ©Melinda Riger @ G B ScubaHogfish ©Melinda Riger @ G B Scuba copy

Hogfish social groups are organized into harems, where one male will protect a group of females in his territory and mate with them.

Hogfish ©Melinda Riger @ GB Scuba Hogfish with isopods ©Melinda Riger @ GB Scuba

CAUTIONARY NOTE Capt. Rick, a loyal follower, has made another of his pertinent comments: “A bit of caution is necessary here! There is some history in the Bahamas of mild to severe Ciguatera poisoning from Hogs. Our M.O. was to only eat Hogs no larger than 5 or 6 lbs. Temporary or permanent blindness, paralysis, and even death is possible with bigger Hogs”. Ciguatera is also a problem with, for example, ‘cuda on Abaco. Those caught on the Marls (west) side are ok to eat; those from the east side have to be treated with circumspection…

Hogfish (with isopod above eye) ©Melinda Riger @ GB Scuba

Credits: all fantastic fish fotos – Melinda Riger at Grand Bahama Scuba

GETTING THE MEASURE OF TURTLES ON ABACO


Hawksbill Turtle ©Melinda Riger @ G B Scub 4

GETTING THE MEASURE OF TURTLES ON ABACO

A recent summer course on Abaco was held in partnership between Elizabeth Whitman (Florida International University) and Friends of the Environment/Frank Kenyon Centre. Participants learned about sea turtle biology and ecology, and discussed potential threats to the vulnerable population. After a classroom session, the team headed out to Snake Cay Creek to carry out a field survey. The turtles caught were measured, weighed, tagged (if not already), and given a general health assessment. Each turtle was then released.

The data captured by such courses is invaluable in the continuing assessment of the health of the local turtle population. In addition, such projects provide a valuable opportunity for people to become involved in a fascinating and rewarding local conservation project – with a literally hands-on experience.

Turtle measuring project, AbacoTurtle measuring project, AbacoTurtle measuring project, AbacoTurtle measuring project, AbacoTurtle measuring project, AbacoTurtle measuring project, Abaco

Credits: Beth Whitman, Friends of the Environment, Jacque Cannon, Maureen Collins, Melinda Riger

SEAHORSES: PREHENSILE TALES FROM THE REEF


Seahorse (Adam Rees / Scuba Works)

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s a year since I last posted about these amazing little creatures, seahorses. I featured a number of photos by Melinda Riger, a couple of videos, some useful facts about them, and for some reason some useless facts that I came across in researching the post. You can chase it down here: SEAHORSES 1

Adam Rees of SCUBA WORKS is another diver, like Melinda, who combines great underwater experience with wonderful photographic skills. This posts showcases some of Adam’s seahorse photography, and if it doesn’t want to make you explore the reefs, I can’t think what will…

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

Seahorse Range MapMap: Seahorse range (Nat Geo)

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

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Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)
Seahorse (Adam Rees / Scuba Works)

Seahorse by Alex Konahin

All phantastic photos: Adam Rees / Scuba Works; Range Map, Nat Geo; Lifecycle diagram, Seahorserun; Seahorse GIF, Alex Konahin

BAHAMAS SHARKS: THE MATING GAME & LITTLE BUDDIES


Shark! Melinda Riger copy

BAHAMAS SHARKS: THE MATING GAME & LITTLE BUDDIES

Sharks: apex predators of the deep. Also, kind to the suckers who hang out with them – REMORAS. In the header image you can see a remora hitching a ride on the shark’s back.

Sharks also seem to enjoy, or at least tolerate, the company of tiny fish – tiddlers so small they don’t even count as a snack or even a canapé. Shark & wee fish ©Melinda Riger @ G B ScubaShark & Tiddler ©Melinda Riger @ GB ScubaShark & buddy ©Melinda Riger @ GB Scuba

Check out the shark-jaw shaped wound on the shark just above. And the rather more dramatic ones on the two sharks below. Shark sex can be a rough old game, and sometimes results in moderate or even severe injury to one participant – or perhaps to both.

Shark with mating marks ©Melinda Riger @ G B ScubaShark mating wounds ©Melinda Riger @ GB Scuba

Credits: all great shark photos recently taken by Melinda Riger, Grand Bahama Scuba

SPONGES ON THE REEF: A COLOURFUL MISCELLANY


Brown Tube Sponge ©Melinda Riger @ G B Scuba

SPONGES ON THE REEF: A COLOURFUL MISCELLANY

It’s time to take an up-close look at some of the sponges you may find as you snorkel or scuba round the reefs of the Bahamas. I am always amazed by how bright and colourful they are, and by their many different shapes and sizes. Even the unpromising sounding (slightly medical, even?) BROWN TUBE SPONGE turns out to be fascinating to examine closely. Here are some more sponge species. 

CANDELABRA SPONGECandelabra Sponge ©Melinda Riger @ G B Scuba copy

STOVE PIPE SPONGEStove Pipe Sponge ©Melinda Riger @ G B Scuba

PURPLE VASE SPONGEVase Sponge, purple ©Melinda Riger @ G B Scuba

BRANCHING TUBE SPONGE WITH ROPE SPONGESponges - Branching Tube Sponge with rope sponge ©Melinda Riger @ GB Scuba

PURPLE TUBE SPONGEPurple Tube Sponge ©Melinda Riger @ GB Scuba

PURPLE SPONGE WITH GIANT ANEMONEPurple Sponge : Giant Anemone ©Melinda Riger @ G B Scuba

VASE SPONGEVase Sponge ©Melinda Riger @ G B Scuba

The above sponges represent a fraction of the sponge varieties found on Bahamas reefs. I’ll post some more quite soon. All this has made me want to go for a snorkel. But right now I am 30 miles from the sea. And I have no gear…

HANG ON A MOMENT! WHAT IS A SPONGE WHEN IT’S AT HOME?

It’s really very simple: if you are ever asked the question, just reply “a sponge is a primitive sedentary aquatic invertebrate with a soft porous body that is typically supported by a framework of fibres or calcareous or glassy spicules. Sponges draw in a current of water to extract nutrients and oxygen”.

AND WHAT, PRAY, IS A SPICULE?

You’re having a laugh… if you seriously want to know, read the abbreviated version about them HERE. And admire this microscopic collage of ‘demospongiae spicule diversity’ made available by the wonders of Wiki and the research of about 20 credited scientists.

Demospongiae_spicule_diversity

All photos: Melinda Riger, Grand Bahama Scuba. Tip of the hat to Wiki and scientists

HAWKSBILL TURTLES: A RARE FIND & SWIMMING WITH ANGELS


Hawksbill turtle (juv), West End Grand Bahama

HAWKSBILL TURTLES: A RARE FIND & SWIMMING WITH ANGELS

There is something unusual about this juvenile hawksbill turtle peacefully noodling round some impressive elkhorn coral with the grunts and sergeant majors. He’s a rarity. He was found at West End, Grand Bahama (just 67 miles swim from West Palm Beach Fl.), a place where hawksbills are very scarce. Loggerheads, they have. And there are plenty of hawksbills elsewhere in Grand Bahama waters. But not at the western tip. So finding this little guy and getting some good photos was a particular pleasure for Linda Cooper. And maybe the presence of a juvenile is a sign that hawksbills may begin to populate the reefs of West End, as perhaps they did historically.Hawksbill turtle (juv), West End Grand Bahama

Linda and her husband Keith run West End Ecology Tours. They have a comprehensive website HERE and a Facebook page HERE. Check it out to see how much there is to explore at West End. The birds, the corals and reef life, the starfish – and a speciality, swimming with rays. To which can now be added the chance of seeing a hawksbill turtle…Hawksbill turtle (juv), West End Grand Bahama

A DOZEN HAWKSBILL FACTS TO CHEW OVER

  • All sea turtles are classed as reptiles (something that always surprises me, somehow)
  • The top shell (carapace) consists of scales that overlap like roof shingles
  • The yellowish bottom shell is called the plastron
  • Adult hawksbills weigh around 100 pounds
  • Sea turtles sleep at night, and can stay underwater for a hours without breathing
  • Hawksbills are omnivorous, eating algae and seagrass but also sponges, urchins and small fish
  • Females lay about 100 eggs like ping-pong balls, and then at once return to the sea for good
  • The sex of baby turtles is determined by relative nest warmth – females from the top eggs
  • Baby turtles hatch almost simultaneously: all must work to dig their way out.
  • They tend to hatch at night and head straight for the sea’s phosphorescence…
  • …except that artificial lights confuse them & lead them away from the sea to likely death
  • Threats: predation, coastal development & habitat destruction, pollution, & illegal collection

SWIMMING WITH ANGELS

As I was writing this, another fact about hawksbills popped into my head. I checked through my archive – mainly Melinda Riger’s wonderful shots from elsewhere on GB – and yes, it is true. There seems to be some sort of symbiotic relationship between the turtles and angelfish. They are often found feeding together. A bit of research confirms this general observation, without giving a clear cause for it. Maybe it is simply that they eat some of the same food; and that there is plenty of it on healthy reefs so there is no cause for aggression on either side. It’s fine for a hawksbill to share with an angel.

10245Green Turtle, Gray Angelfish ©Melinda Riger @GB Scuba copyTurtle with Gray Angelfish ©Melinda Riger @ G B Scuba copyHawksbill Turtles, French Angelfish eat sponge ©Melinda Riger @ GB Scuba copyHawksbill Turtle eats sponge ©Melinda Riger @ GB Scuba copy

NOTE The Hawksbill is listed as Critically Endangered by the IUCN red list of Threatened species as its populations have declined dramatically throughout the world and especially in the Caribbean region. It is listed in Appendix I of the Convention on the InternatIonal Trade of Endangered SpecIes (CITES) meaning that Hawksbills are near extinction or very endangered. All marine turtles are now protected under Bahamian law, as is the taking of eggs.

Credits: West End Ecology Tours / Linda & Keith Cooper (photos 1, 2, 3); Melinda Riger / Grand Bahama Scuba, all other images; BAHAMAS NATIONAL TRUST  for their very useful fact-sheet (one of many) which I have adopted and adapted; Aquoflite for the vid.

JACKKNIFE FISH: BAHAMAS REEF FISH (30)


Jackknife Fish ©Melinda Riger @ GB Scuba

JACKKNIFE FISH: BAHAMAS REEF FISH 30

The rather uncomfortably ‘double-k’  Jackknife fish is one of 3 types of similar drumfish subspecies of Equetus found in Bahamas waters. The others are the High Hat and the SPOTTED DRUMFISH – the first fish featured in this series. Each of these drumfish species has juveniles that are elegant and delicate, becoming more conventionally fishlike as they grow to adulthood, as the final image shows.

Jackknife fish (juv) ©Melinda Riger @ G B Scuba copy

I always want to stick a hyphen in to separate each k: jack-knife fish. I think it’s an English thing. I have seen, at the other extreme, ‘jack-knifefish’, which looks most weird of all. Checking online, jackknife fish wins by a distance as the correct spelling. 

Jackknife Fish (juv) ©Melinda Riger @GB Scuba

These little fish, typically between 6 and 9 inches, inhabit the coral reefs of the Caribbean, the Gulf of Mexico, Florida and the Bahamas. Juveniles eat plankton and similar organism, graduating to small crabs and shrimps as adults.

Jackknife Fish ©Melinda Riger @ G B Scuba

A FULLY GROWN JACKKNIFE FISH (NOAA)Jackknife fish adult_NOAA_Photo_Library

Like other drumfishes, the jackknife can produce ‘croaking’ or ‘drumming sounds. This involves the fish beating its abdominal muscles against its swim bladder. There’s a lot more to it than my rather simplistic summary, but it’s probably as much as anyone needs or wants to know… The primary reason is believed to relate to mating. Other reasons include ‘low-level aggression’, and keeping in touch with each other in turbid waters.  I prefer the unscientific theory that sheer happiness makes them croak. Here’s a short video of a happy juvenile Jack knife fish (that’s yet another spelling variant…)

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Credits: Melinda Riger / GrandBahama Scuba; NOAA