‘TREAT WITH PATIENCE…’ – NURSE SHARKS IN THE BAHAMAS


Nurse Shark ©Melinda Riger @ GB Scuba

‘TREAT WITH PATIENCE…’ – NURSE SHARKS IN THE BAHAMAS

The scientific name for the nurse shark sounds like something Bilbo Baggins might have said to summon elves to his rescue: Ginglymostoma cirratum. Actually the name is a mix of Greek and Latin and means “curled, hinged mouth” to describe this shark’s somewhat puckered appearance. The origin of the name “nurse shark” is unclear. It may come from the sucking sound they make when hunting for prey in the sand, which vaguely resembles that of a nursing baby. Or it may derive from an archaic word, nusse, meaning cat shark. The most likely theory though is that the name comes from the Old English word for sea-floor shark: hurse.

Shark ©Melinda Riger @ GB Scuba

Nurse sharks are slow-moving bottom-dwellers and are, for the most part, harmless to humans. However, they can be huge—up to 14 feet (4.3 meters)—and have very strong jaws filled with thousands of tiny, serrated teeth, and will bite defensively if stepped on or bothered by divers who assume they’re docile. [There are recorded instances of injuries caused to divers who have tried to pull nurse sharks by the tail. And serve them right, I say. Treat them with patience – and respect!] 

Nurse_shark_with_remoras Duncan Wright (Sabine's Sunbird)

Notice that the nurse shark in the above photo, and in the header image, is being attended by REMORAS. Click the link to find out more about the strange relationship these ‘weird suckers’ have with larger marine creatures.

Nurse Shark ©Melinda Riger @ G B Scuba

They use their strong jaws to crush and eat shellfish and even coral, but prefer to dine on fish, shrimp, and squid. [And also stingrays, apparently. They have been observed resting on the bottom with their bodies supported on their fins, possibly providing a false shelter for crustaceans which they then ambush and eat.] They are gray-brown and have distinctive tail fins that can be up to one-fourth their total length. Unlike most other sharks, nurses are smooth to the touch. 

Nurse Shark ©Melinda Riger @ Grand Bahama Scuba

Nurse sharks are found in the warm, shallow waters of the western Atlantic and eastern Pacific oceans. They are abundant throughout their range and have no special conservation status, although the closeness of their habit to human activities is putting pressure on the species.

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Nurse sharks are nocturnal and will often rest on the sea floor during the day in groups of up to 40 sharks, sometimes piled on top of each other.

Shark, Nurse (young) ©Melinda Riger @ GB Scuba

FAST FACTS

  • Type: Fish 
  • Diet:  Carnivore
  • Size: 7.5 to 9.75 ft (2.2 to 3 m)
  • Weight: 200 to 330 lbs (90 to 150 kg)
  • Size relative to a 6-ft (2-m) man:
Illustration: Shark compared with adult manNurse Shark ©Melinda Riger @ G B Scuba copy

Credits: All photos Melinda Riger, Grand Bahama Scuba; range map and text mostly  NATIONAL GEOGRAPHIC  filled out with other pickings

‘ELEGANTLY WEIRD’ – SPOTTED DRUMFISH JUVENILES: BAHAMAS REEF FISH (20)


‘ELEGANTLY WEIRD’ – SPOTTED DRUMFISH JUVENILES: BAHAMAS REEF FISH 20

I’ve posted before about the rather extraordinary SPOTTED DRUMFISH, one of those reef fish which in juvenile form is very different from the adult. This species was first up in the Bahamas Reef Fish series – click above link. Here are a few recent images, courtesy of Melinda Riger. The first three show the juvenile form (note the piscine photobomb in the first one). The last shows a group of adults hanging out on the reef with (I think) some soldierfish. You can see how the juvenile drumfish becomes the adult, but those little stripy bullet-heads with their two long elegantly trailing appendages differ considerably from the rather solid-looking spotty / stripy adults with their dramatic punko-rockabilly quiffs.

Drumfish (juv) 3 ©Melinda Riger @ Grand Bahama Scuba Drumfish (juv) 4 ©Melinda Riger @ Grand Bahama ScubaDrumfish (juv) 2 ©Melinda Riger @ Grand Bahama Scuba Drumfish ©Melinda Riger @ Grand Bahama Scuba

CETACEAN SENSATION: SPERM WHALES & DOLPHINS ON ABACO


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CETACEAN SENSATION: SPERM WHALES & DOLPHINS ON ABACO

July has been ‘Whale Camp’ month for the BMMRO, when a small group of lucky youngsters get to spend time out at sea searching for whales and dolphins, and learning the intricacies of data recording and research. One target was the sperm whale, a species that may be found off the coasts of South Abaco. This is a favoured place because the deep trench of the Great Bahama Canyon throws up the food these whales need (see map below).

After some time spent searching, the BMMRO reported  “the sperm whales are back! We found a single animal yesterday, and finally in the evening found the rest of the group, 10+ animals including 3 mother-calf pairs, and dolphins at Rocky Point!” Here are some of the photos from the trip.

Sperm Whale Tailing, Abaco, Bahamas (BMMRO) Sperm Whale, Abaco, Bahamas (BMMRO) Sperm Whale, Abaco, Bahamas (BMMRO)

This map of the northern Bahamas shows the V-shaped tails of the Great Bahama Canyon, and explains why the east coast and (in particular) the shallower south-west coast between Hole-in-the-Wall and Rocky Point is so attractive to feeding whale species.

Great Bahama Canyon

The dolphins were quite prolific in July, in particular bottlenose and spotted dolphins. These photos were mostly taken while the search for sperm whales was going on: the BMMRO posted “lots of dolphins up at Gorda Cay yesterday… still not hearing any sperm whales in the area, has been a couple of weeks without sign of them so they should be showing up again soon…” As they obligingly did!

Bottlenose Dolphin, Abaco, Bahamas (BMMRO)Bottlenose Dolphins, Abaco, Bahamas (BMMRO) Bottlenose Dolphin, Abaco, Bahamas (BMMRO)Spotted Dolphins, Abaco, Bahamas (BMMRO)

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Today is the first day of the crawfish season and Facebook Abaco has been crawling with crawfish for a couple of days in feverish anticipation. So I decided to stick with whales and dolphins instead because there are enough crawfish images out there to keep anyone happy. However I did particularly like this offering today from Albury’s Ferry Services, always a byword for tastefulness and decorum. I’ve borrowed their picture (they borrow mine sometimes) – I wondered if it need a little more exposure, then decided there was probably quite enough already….

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Photo credits: all cetaceans, BMMRO; Crawfish Ladies, Albury’s Ferries; ‘Keep Calm’, Mariah Sawyer

THE OCTOPUS: MARINE BAGPIPES FILLED WITH INK


 THE OCTOPUS: MARINE BAGPIPES FILLED WITH INK

Few people know that, by international law, it is unlawful to fail to be fascinated by Octopuses… Octopi… Octopodes… Octopotomi… Whatever. For a learned dissertation on the correct plural form for these creatures – bear with me, there are strict rules that apply here – you’ll find out the right way at THE PLURAL OF OCTOPUS I won’t go into it all now, because it’s time to showcase some more wonderful underwater photography by Melinda Riger of Grand Bahama Scuba. Strictly, these are not Abacos Octos, but they share the same reef system and are therefore close cousins. Of such tenuous links are blog posts formed.

My favourite octopus photoOctopus ©Melinda Riger @ Grand Bahama Scuba

Settling down to a take-awayOctopus + dinner ©Melinda Riger @ GB Scuba

The all-seeing eye…Octopus ©Melinda Riger @ G B Scuba

On the move… so long suckers!Octopus  ©Melinda Riger @ Grand Bahama Scuba

Octopus InkOctopus Ink ©Melinda Riger @ G B ScubaAll photos: Melinda Riger

The Rare Scottish Tartan Octopus

Bagpipe

SAD POST SCRIPT:  As a Scot out of Norway (did you ever?) my father learnt to play the bagpipes. Indeed had a set. They lived in a cellar I wasn’t allowed into. The bag was allegedly preserved in treacle (don’t ask). I still have the ‘Chanter’ (a single pipe practice instrument), the sound of which is akin to trying to strangle one cat with another cat. I was fobbed off with that. Then one day as a treat the cellar was unlocked and a large wooden box was dragged out. The bagpipes! The lid was opened and… OMG! the bag had rotted away completely, the pipes looked pathetic and very disappointing, and the whole thing stank of nameless dead creatures… I can’t hear the sound of the pipes to this day without finding it (a) stirring yet (b) enough after a short time and (c ) a reminder of a broken dream… The end.

‘TAKEN TO THE CLEANERS': REEF FISH & CLEANING STATIONS


Goby (Cleaning) © Melinda Riger @ G B Scuba copy

Cleaning Goby (Melinda Riger)

‘TAKEN TO THE CLEANERS': REEF FISH & CLEANING STATIONS

A cleaning station is a place where fish and and other aquatic life congregate to be cleaned. This involves the removal of parasites both externally and internally, and is be performed by various creatures including, on the coral reefs of the Bahamas, cleaner shrimps and various species of cleaning fish such as wrasses and gobies. The process conveniently benefits both the cleaned and the cleaner.

Tiger Grouper being cleaned by Cleaner ShrimpsGrouper being cleaned ©Melinda Riger @ GB Scuba copy

Blue Parrotfish being cleaned (or tickled, from its expression) by a Cleaner Shrimp Blue Parrot Fish & Peterson Cleaner Shrimp ©Melinda Riger @ G B Scuba copy

  Black Grouper being cleaned by gobies – note the ones in its mouth Grouper at cleaning station ©Melinda Riger @ G B Scuba copy

Black Grouper at a Cleaning Station with gobies. Note the hook and line… Grouper, Black, at cleaning station (+ hook) ©Melinda Riger @ GB Scuba copy

Tiger Grouper being cleaned by GobiesTiger Grouper being cleaned ©Melinda Riger @G B Scuba copy

Gobies checking a hand for parasites….Cleaning Gobies copy

When a fish approaches a cleaning station it will open its mouth wide or position its body in such a way as to signal that it needs cleaning. The cleaner fish will then remove and eat the parasites from the skin, even swimming into the mouth and gills of the fish being cleaned.

“Clean me!” An amazing view of a Tiger Grouper at a CleaningStation with its gills wide openGrouper, Tiger - gills open at cleaning station ©Melinda Riger @GB Scuba copy

Grouper at a cleaning station over a spongeSponge : Fish Cleaning Station ©Melinda Riger @ G B Scuba copy

Remora clinging to a shark. For more on this unusual symbiotic relationship, click HERE383586_510314062323321_1002533913_n copy

 All photos: Melinda Riger of Grand Bahama Scuba, with thanks as ever

AMAZING WHALE, DOLPHIN & MANATEE PHOTOS FROM ABACO


Whale Fluke (BMMRO Abaco Bahamas)AMAZING WHALE, DOLPHIN & MANATEE PHOTOS FROM ABACO

The BMMRO (Bahamas Marine Mammal Research Organisation) had a great June for sightings of cetaceans and sirenians. Here is a sample of their wonderful photos from recent research expeditions (with thanks as ever for use permission).

RANDY THE WEST INDIAN MANATEE

After the recent excitement of Abaco’s manatee GEORGIE having returned to Cherokee after another of her epic journeys, another West Indian manatee has arrived at Sandy Point (conveniently the location of the BMMRO HQ). Sirenians and cetaceans are generally recognised from particular patterns to flukes or fins. The second image shows the notch in Randy’s tail that confirms ID.

Randy the West Indian Manatee, Sandy Point, Abaco, Bahamas Randy the West Indian Manatee (tail), Sandy Point, Abaco, Bahamas

BOTTLENOSE DOLPHINSBottlenose Dolphins - BMMRO, Abaco, BahamasBottlenose Dolphins - BMMRO, Abaco, BahamasBottlenose Dolphins Abaco BMMRO FV

SPOTTED DOLPHINSSpotted Dolphins, BMMRO Abaco, Bahamas

BLAINVILLE’S BEAKED WHALESBlainville's Beaked Whales BMMRO Abaco, BahamasBlainville's Beaked Whales BMMRO Abaco, BahamasBlainville's Beaked Whales BMMRO Abaco, Bahamas

TWO COMPLETE FLUKES (THIS IMAGE & HEADER)

(note minor damage to the edges, from which ID of an individual can be made)Whale Fluke (BMMRO Abaco Bahamas)

SPERM WHALE & DIVER

Compare the diver’s fins in the foreground with the (partial) length of a huge sperm whale… Sperm Whale and Diver

RELATED LINKS:

DOLPHINS

WHALES

MANATEES

“TOOTHY CRITTERS”: BARRACUDA ON ABACO


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“TOOTHY CRITTERS”: BARRACUDA ON ABACO

We’ve had some sharks swimming around the blog, for example HERE. But not a great deal about barracudas. Time to put that right. Melinda Riger’s excellent photographs tell you the basics of what you need to know – they are lean, mean biting machines with wicked teeth. In fact, ‘cuda bites are quite rare (unless you you very stupid or very unlucky) and many of the common sense rules that apply to fraternising with sharks in their own element apply equally with ‘cudas.

Barracuda & Diver ©Melinda Riger @ G B Scuba

Great gnashers – some teeth angle forwards & some backwards for mincing prey effectivelyBarracuda ©Melinda Riger @ G B Scuba Barracuda ©Melinda Riger @ GB Scuba copy 800px-Barracuda_laban

Lobbing a brightly-coloured lure from a skiff using a spinning rod into the general vicinity of a barracuda can result in a heart-stopping few seconds as the fish plunges towards the lure at astonishing speed. If it takes it, there’s even more fun to be had bringing it in. ‘Cuda steaks are delicious, but some care needs to be taken. These fish are known carriers of CIGUATERA fish-poisoning. Click the link to find out about the unpleasantness of the toxin involved. On Abaco, ‘cudas from one side of the island are OK, and from the other side may be suspect… just make sure you know which is which before you cook your supper…

BARRACUDA ©Melida Riger @ G B  ScubaBarracuda ©Melinda Riger @ GB Scuba