COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS


Cookiecutter Shark mouth, jaws & teeth (BMMRO Bahamas)

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

The Cookiecutter shark Isistius brasiliensis (aka the less scary, more genial sounding ‘cigar shark’), might be an ideal candidate for a Room 101 nemesis.** These little beasts – a species of dogfish shark – are found in several mainly island-based areas dotted around the globe, including in Bahamas waters.

 

HOW COME THE NAME?
These sharky little b@st@rds (*scientific term*) attack marine mammals and fishes, attaching themselves by suction and gouging out perfect round plugs of skin and flesh, leaving what are sometimes called ‘crater wounds’. Then they eat them. Imagine getting hold of a really sharp domestic cookie cutter with circular rows of razor-sharp teeth, and grinding it hard into your thigh. There! That! 
The size of an adult shark:16″ max
The term ‘cookiecutter’ is also a pejorative slang term, meaning mass-produced, lacking in originality, or boringly samey, as in cookiecutter cars or TV genres etc. The little critters under consideration here are anything but…
                        

HORRIFYING COOKIECUTTER FACTS

  • Live in the depths, rise vertically in the day & dive back down at dusk
  • Undersides have light-emitting ‘photophores’ which emphasise…
  • …the dark collar which acts as a lure, resembling a small innocent fish
  • Bioluminescence lures prey & confuses predators (more on this below)
  • The glow is so strong it may last for some time after removal from water

  • Their lips are ‘suctorial’ = they attach tightly to their target
  • The jaws then gouge out the victim’s flesh in a remarkably neat circle
  • Omni-vicious: any medium to large ocean creature is vulnerable to attack
  • There are even occasional reports of humans being targeted

Here are two Blainville’s beaked whales that I photographed from the BMMRO research vessel. The top whale has a number of circular healed attack marks and a recent one. You can see how deep the gouged hole is. The other has well-healed scars.

Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

  • Multi-toothed: top rows of small teeth, rows of larger teeth on the bottom
  • The lower teeth are the cutters, acting like a saw when locked on
  • See header image and below for full details

    

HOW EXACTLY DO THEY DO WHAT THEY DO?
I can explain it no better than the renowned authority Prof. W. K. P. Dear:  “the suctorial lips ensure a tight seal. It then bites, using its narrow upper teeth as anchors while its razor sharp lower teeth slices into the prey. Finally, the shark twists and rotates its body to complete a circular cut, quite possibly aided by the initial forward momentum and subsequent struggles of its prey. The action of the lower teeth may also be assisted by back-and-forth vibrations of the jaw, a mechanism akin to that of an electric carving knife”.

                 ARE THESE SHARKS ‘PARASITES’, WOULD YOU SAY?

The behaviour of these sharks is an example of a symbiotic relationship between two species that is parasitic. This means essentially that one gains and the other suffers (eg humans & no-see-ums). This is distinct from commensalistic symbiosis, where one species gains and the other is unaffected (e.g. cattle egrets with cattle); and mutualistic symbiosis, where both gain (e.g. cleaner fish & groupers). So, in a word, yes.

  • An ‘ambush predator’: these little sharks ‘hover’ in the water column waiting…
  • They are capable of rapid movement to catch up & latch onto prey
  • They will eat a passing small fish, crustacean or even squid as a snack
  • Sometimes they operate in schools; there is safety in numbers
  • The schools are thought to increase the ‘lure’ effect of the dark collar

A beached whale that’s been heavily targeted

FUN FACT TO COUNTERACT THE BAD STUFF

In the late c20, more than 30 U.S. Navy submarines were forced back to base to repair damage caused by cookiecutter shark bites, either to the neoprene footings of sonar domes or to rubber-sheathed cables. The problems were solved by using fibreglass. Oceanographic equipment and telecommunications cables are also recorded as being damaged by these sharks.

Cookiecutter Shark – the real deal

MONSTERS OF THE DEEP

These great cards from the weirdly spelled WIERD ‘N’ WILD CREATURES provide excellent factual info. Their CCS card is no exception. You’ll find more details here about the effect of the bioluminescence and so on, written as clearly as I might hope to. 

Cookiecutter Shark Facts (Monsters of the Deep)Cookiecutter Shark Facts (Monsters of the Deep)

** “The worst thing in the world varies from individual to individual. It may be burial alive or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.” (George Orwell, 1984). Being in a tank with some cookiecutters might count.

Alright now… the wounds eventually healBlainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

Credits: BMMRO – header image; beaked whale photos – Keith Salvesen / BMMRO; Te Ara NZ for the main jaw image; all small images with thanks to Wiki and respective photographers who took the time to upload them for all to enjoy & learn from; ‘wierdnwonderful creatures’ for the monster card; range map from Wiki

SHARK ATTACKS – ABACO, BAHAMAS, & BEYOND


Shark! Melinda Riger, Grand Bahama Scuba

SHARK ATTACKS – ABACO, BAHAMAS & BEYOND

Over the last couple of weeks or so I have been getting a lot of hits for Shark Attack information. There have been 2 or 3 recent incidents including a tragic (and very rare) death in Maine, which may well account for this. The Shark Attack details I have accumulated and posted over the years are buried in an historical sub-sub-page, so to make things easier I have rechecked and updated the latest data resources and their links, and put them in a mainstream post. This is it.

DATABASE UPDATE 2020

INTERNATIONAL SHARK ATTACK FILE

PRIMARY RESOURCE

This resource is the portal to a mass of current, recent, and historical data, presented with authority and clarity. It provides undoubtedly the most comprehensive and accessible global shark-incident data of all.

Last year I included informative screen-shots taken from this site. For now I am confining the information to the most useful direct links. More work for the reader, perhaps, but also a better chance to explore and understand the hows, whens and wherefores of shark-related incidents – and how best to avoid the situation in the first place.

SITE LINK

https://www.floridamuseum.ufl.edu/shark-attacks/

BAHAMAS-SPECIFIC

https://www.floridamuseum.ufl.edu/shark-attacks/maps/na/bahamas-antilles/

The 2019 worldwide total of 64 confirmed unprovoked cases were lower than the most recent five-year (2014-2018) average of 82 incidents annually. There were five fatal attacks this year, two of which were confirmed to be unprovoked. This number is in line with the annual global average of four fatalities per year

MENU SELECTION

 Maps & Data    Contributing Factors    Shark Attack Trends 

What are the Odds?   Reducing Your Risk

For anyone thinking of entering waters where sharks live – eg scuba divers, spear-fishers, swimmers, boaters – with relatively little experience or knowledge, these links will be incredibly useful. Local knowledge is well worth having as well. A young friend of ours, an intern on Abaco, was warned against spearfishing at a particular location: “Fish there, you’ll get ate”. He did. He very nearly was.

“Humans are not on the menu of sharks. Sharks bite humans out of curiosity or to defend themselves”

The SRI produces a  downloadable Global Shark Attack File that provides:

  • A downloadable incident log by country
  • A downloadable incident log chronologically
  • A world map of encounters categorized by provoked vs. unprovoked, incidents involving boats, air & sea disasters and questionable incidents
  • To read any basic case report, open the Chronological file, click on the case number (column A) and the report will open as a pdf file

SHARK SPECIES (CONCISE OVERVIEW FOR EACH SHARK)

http://www.sharkattackfile.net/species.htm

BAHAMAS-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas

ABACO-SPECIFIC STATS

http://www.sharkattackdata.com/gsaf/place/bahamas/abaco_islands

Credits: All great shark photos – Melinda Riger / Grand Bahama Scuba; ‘Infest’ sticker design, Tracie Sugo

A FINAL THOUGHT

 

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE


Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE

There’s never a day without a ‘Day’, nor a week without a ‘Week’. Almost all creatures under the sun are celebrated in some regular calendar-based time-frame. With the exception of No-see-ums: I’ve checked – there is no national or international Ceratopogonidae Day in any online calendar. 

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

By a mere 2 days, I have missed Shark Week, a happening tied in with the Discovery Channel, and heralded by an amusing trailer that features no actual sharks… So, belatedly, here are some cool shark photos to enjoy, in case you didn’t get enough of them last week, or (like me) had other fish to fry.

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba“I’m so glad we agreed to watch each other’s backs…”

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

 Meet Nurse Betty, as she is known to diversSharks in Bahamas - Melinda Riger / Grand Bahama Scuba

MANGROVES: THE SHARK NURSERY

As all children are taught and some adults know, the mangroves that grow in the shallow waters around the islands of the Bahamas are of enormous ecological significance. This isn’t the place to expand on that now, but it is worth mentioning that the mangrove swamps are the nurseries of young sharks (‘pups’) until, as juveniles, they are old enough to leave the safely of their home for deeper waters. Check out the short video below.

Sharks in Bimini Bahamas - biminis-marine-protected-areaSharks in Bimini Bahamas - biminis-marine-protected-area

Spot the REMORA hitching a ride on this shark’s backSharks in Bahamas - Melinda Riger / Grand Bahama Scuba

Nurse shark – note the twin barbels (cf recent Goatfish article)Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

HAMMERHEADS FROM BIMINI Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet   Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet

These wonderful photos were all taken in Bahamian waters. Melinda Riger of Grand Bahama Scuba is, as ever, the star snap-getter of sharks (and indeed all other marine creatures). Special thanks are also due to Grant Johnson / 60poundbullet and Neal Watson / Bimini Scuba Center for occasional use permission of photos – especially of hammerheads – that are, well, eye-popping. Video from ‘ZeroEye’

Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet