What goes in has to come out…somehow. So, do sharks poop? They sure do! Every living animal that consumes food has to have a way of getting rid of waste. Sharks are no different. Researchers love poop because it holds clues to what sharks eat, where they may be from and even stress levels. Sharks can be hard to study, and they are migratory so harder to track. Yet when samples of feces can be collected scientists can gather all kinds of valuable data. Let’s take a look at three different species of sharks, that have very different diets, and how their digestion works and what comes out when they are done.
How Whale Sharks Poop
Let’s just get it out there, you would think if you have a big fish you would have big poop, right? Well, whale sharks are the biggest fish alive with the largest whale sharks getting over 60 feet long and weighing more than 15 tons, but they do not consume large prey, they are filter-feeders, similar to some whales!
Whale swim slowly through the water with their large mouths (some are four feet wide!) and collect plankton, small shrimp and copepods that go through a sieve. The water goes through the gill slits and the food is left behind. Every now and again the whale shark closes its mouth forcing the food down to its stomach. They have rows and rows of tiny teeth (each one about 6mm long) but they do not use their teeth to chew. The food passes on to their stomachs where it is digested and then on to the intestines. The body absorbs the nutrients it needs and expels the rest in a cloud of feces. Here is a video that shows the giant sharks expelling their latest dinner.
What goes in Whale Sharks (what they eat):
Whale sharks eat a diet of tiny animals, which might be surprising since they’re just gigantic animals!
What comes out of Whale Sharks (what does their poop look like)?
Whale sharks may just be swimming around when they wriggle a bit and expel a cloud of feces. The cloud is a mix of what they just ate but since a large portion of their diet is vegetation it appears as a green cloud of waste. The shark’s bile, which is green, also mixes in and is excreted. Recently scientist have been able to study the feces of several whale sharks and are finding that they are much more vegetarian than suspected. They can evaluate the contents of the feces for nutrient levels and the chemical composition of the waste.
Great White Sharks: Carnivores sharks that swallow their food whole!
Great white sharks are clearly not vegetarians, we don’t need to exam their poop to come to that conclusion. Great whites are aggressive predators that eat seals, sea lions, sea turtles and even other sharks. They can grow to a maximum length of about 20 feet in length and have rows and rows of large sharp teeth, and they do use their teeth for eating. Not so much for chewing but more as a means of snagging prey and forcing it down their throats. Great white sharks have a U-shape stomach with a large capacity.
Let’s take the example of a Great White attacking a seal and biting off sections of it (it can bite a 30lb section of meat at one time) and swallowing it whole. The shark may continue to feed until it is full or they may be in a shark feeding frenzy with other sharks. Once the food source has been consumed the enzymes and acids in the sharks stomach will start to break down the food. Seals, as you know have bones and teeth and other non-edible parts. The shark will vomit these up back into the ocean.
There is another video of a Great White pooping right in front of a cage of scuba divers. The Great white has a ritual of contorting into an S-shape and wriggling to force out the feces. The shark caught on tape also opens its mouth right before expelling its waste. A researcher that examined the film suggested this may be like humans that make a face when having to “push”. The Great White shark expels a green cloud of feces and smaller fish swarm around to finish off any undigested nutrients.
What goes in Great White sharks (what they eat):
- Sea Lions
- Sea turtles
- Smaller sharks
What comes out of Great White sharks (what does their poop look like?)
Great white poop is also a cloud of green feces mixed in with the green bile and yellow bilirubin that have been used to break down the food. Similar to using cow manure on fields to add nutrients to the soil, shark waste adds nutrient back into the water. There is usually enough undigested food for smaller fish to feed off a recent mix from a shark’s feces.
Tiger Sharks: The waste basket of the sea
Tiger sharks are known to eat just about anything. How do researchers know that? They have found tiger sharks over the years and examined the contents of their stomachs. The strangest items that have been found include cans, bottles and a even a bible. Remnants of land animals that may have fallen into the water to meet their untimely death have also been found. Animals like chickens, pigs and hyenas. How do tiger sharks digest such crazy items? They don’t. They are not discerning about what they eat, they let their stomach digest the items that have nutrients and can fit, but the Tiger shark has the ability to invert its stomach so that it comes out its mouth and dump the remnants into the ocean, similar to turning a plastic bag inside out. Once it is empty and rinsed with sea water it can swallow it again and it will go back to its place, ready for the next meal.
What goes in Tiger sharks (what they eat):
- Marine birds
- Small sharks
What comes out of Tiger sharks (what does their poop look like)?
Tiger sharks have a similar system as the Great White and also pass a large green cloud of feces. Their digestive system also contains strong enzymes and acids that help digest the food in the stomach and livers that help with the digestion in the intestines.
While we are on the subject, do sharks pee?
No, not really. Sharks actually pee through their skin! The skin absorbs the pee and then it is excreted through the skin. Kind of important to know if you are making shark for dinner!