Description & Behavior
Cookiecutter sharks, Isistius brasiliensis (Quoy and Gaimard, 1824), aka cookie-cutter shark, smalltooth cookiecutter shark or cigar shark, are small, deepwater sharks named for the cookie-shaped wounds they leave on larger fish and marine mammals.
Cookiecutter sharks live in the warm, deep waters of equatorial oceans, primarily in coastal waters near islands. They inhabit deep waters below 1,000 m during the day and migrate into surface waters at night at around 300 m. They have been found in depths up to 3,500 m.
Feeding Behavior (Ecology)
Cookiecutter sharks, appear to blend with the light from above when viewed from below due to the shark’s ventral photophores that disguise the shark’s outline. The primary prey of the cookiecutter shark are squid, small fish (likebristlemouths), and crustaceans.
This shark also feeds on larger pelagic animals such as wahoo, tuna, billfishes, and marine mammals. It is a facultative ectoparasite, which means that it feeds on the flesh of other species causing them harm but not death and it is not dependent on these species for survival.
A dark patch on the ventral surface of the cookiecutter shark resembles a smaller fish when viewed from below and is thought to lure larger fish and marine mammals that may be swimming beneath it. When this sneaky predator attacks its prey, it grabs hold of the flesh with its lips and bites using its small, sharp upper teeth to grip the prey while it cuts the flesh with the large, serrated lower teeth. The cookiecutter shark then spins its body to remove a “cookie-shaped” plug of flesh which it swallows before releasing its prey.
Unlike other shark species that lose teeth individually, the teeth of the cookiecutter shark are shed as a single unit. The bottom teeth are swallowed, possibly to help maintain calcium levels in the body.
Cookiecutter sharks are ovoviviparous. Hatching takes places between 12-22 months with 6-12 pups per litter. When the young emerge, they are fully developed and able to hunt for food by themselves. Males mature at 36 cm and can grow to a size of 42cm. Females mature at 39 cm and can reach up to 56 cm.
Ovoviviparous: eggs are retained within the body of the female in a brood chamber where the embryo develops, receiving nourishment from a yolk sac. This is the method of reproduction for the “live-bearing” fishes where pups hatch from egg capsules inside the mother’s uterus and are born soon afterward. Also known as aplacental viviparous.
Conservation Status & Comments
Senegal, Mauritania, Mali, Burkina Faso, Niger, Nigeria, Chad, Sudan, Eritrea, Ethiopia, and Djibouti. Those are the countries. It will be drought-resistant species, mostly acacias. And this is a fucking brilliant idea you have no idea oh my Christ
This will create so many jobs and regenerate so many communities and aaaaaahhhhhhh
more info here: http://en.wikipedia.org/wiki/Great_Green_Wall
it’s already happening, and already having positive effects. this is wonderful, why have i not heard of this before? i’m so happy!
For more posts like this, follow Ultrafacts
I laughed I cried, I researched stars, and sobbed about elephants. But nothing compares to how happy the last one made me feel.
Check out the article about this: Global catches, exploitation rates, and rebuilding options for sharks
ANOTHER ANATOMY POST! Only three vertebrate groups have successfully evolved flight: Birds, Bats, and Pterosaurs, which are NOT dinosaurs, and are an extremely diverse group of reptiles! Pterodactyl is not the only one. However, birds ARE dinosaurs. Avian dinosaurs!
Wings are not some extra structure you tack on to a creature and somehow the arms go away— they ARE arms. Think about that when you are designing creatures with wings and also giving them arms. That means your creature has six limbs.
Next anatomy post: The anatomy and evolution of DRAGONS. If you guys have any requests, feel free to send them in!
I remember I cried over this like a baby.
When I think I have cried over every possible thing on earth I discover it’s not true
Welcome to the United States of America.
What the actual fuck.
dude if you make bill nye scowl, you need to re-evaluate your relevance to this planet
You guys want to know why the government doesn’t want us to use renewable resources???? BECAUSE THEN THEY MAKE NO MONEYYYYYY.
Paleontologists found this sweet whorl of teeth called a Helicoprion, but really didn’t know how it might have been situated in a fish’s mouth.
There were many theories postulated about how the teeth fit in the animal’s mouth (fourth image). When another specimen was found, it was determined that the owner of this strange jaw (not a shark, but a ratfish) had no upper teeth at all.
Ladies and gentlemen, the most metal fish.
(via Laelaps/National Geographic) Art by Ray Troll.
Horned shark hatching