Consider that 70 percent of the Earth is covered with water, and the oceans hold 96.5 percent of that water. Marine biologists who study the ocean's animals continue to learn fascinating new facts about the animals that live in the seas. Sharing a few, fun facts about marine animals with children might ignite a deeper interest in the ocean, which our planet's health depends on.
While each animal in the ocean plays an important role in the ecosystem, the parrot fish might be among the ocean's hardest workers. A single parrot fish produces, annually, up to 200 pounds of sand, according to Pewenvironment.org. If you've been to a tropical beach near a parrot fish-inhabited coral reef, you've wiggled your toes in their sand. Using its beak, formed by protruding teeth, the parrot fish breaks algae-containing coral skeleton from the reef. Grinding the hard coral with teeth in the back of its throat, the parrot fish digests the algae and excretes pulverized coral -- aka sand. Squeamish kids might appreciate that the coral sand was not digested by the fish. In a symbiotic relationship with the reef, parrot fish remove smothering algae and prune coral while they dine. You'd think parrot fish could use serious dental work, but their teeth continually renew.
Cleaner fish, such as goby, and the species of wrasse known as cleaner wrasse, have dangerous jobs. They graze on parasites and dead tissue clinging to bigger fish, and in doing so, even enter their mouths. In this symbiotic relationship, the cleaner fish gets a good meal, and its food servers get a good cleaning. Distinct markings on cleaner fish -- a blue bar on the silver, cleaner wrasse -- identify them to bigger fish, which rarely attack. According to a study completed by Redouan Bshary at the University of Neuchatel in Switzerland, even small fish waiting their turn at the cleaning station are safe, thanks to the calming effect the cleaner fish have on the predators.
Strange Sleep Habits
Many species of sharks must swim for their lives -- literally. Constant movement is the only way they can keep oxygen-providing water flowing through their gills. No wonder sharks look so grumpy. Or maybe they aren't tired after all. According to ReefQuest Centre for Shark Research, the part of the shark that controls its swimming movements is in the spinal column instead of the brain, meaning the shark needn't be awake to swim. Other sharks, such as nurse sharks, have gills that work while they sleep. Unlike humans and other mammals, dolphins must stay awake to breathe air from the surface. So why aren't dolphins cranky and tired? The two sides of this mammal's brain take turns sleeping. If you're on a boat and see a dolphin with one eye open and the other shut, it's probably not winking at you. It's getting some needed shut-eye.
Underneath the blue water off Australia’s Queensland coast, one of the planet's tiniest animals, coral, formed the world's largest biological feature, the Great Barrier Reef. This network of nearly 3,000 reefs, built upon layer after layer of the limestone skeletons of more than 400 types of coral, took millions of years to grow. The Great Barrier Reef spans more than 1,250 miles, north to south, covering an area larger than Montana. Reefs protect coastal areas from surges and large waves. And they provide fascinating glimpses of reef animals. More than 1,625 types of fish inhabit the Great Barrier Reef, along with many other marine animals, making it the most diverse of all World Heritage sites and of high scientific and ecotourism value.
- USGS – Water Science School: How Much Water on Earth
- National Geographic: Parrot Fish
- PEW Charitable Trusts: Save a Fish, Preserve an Ecosystem
- Oceana: Marine Wildlife Encyclopedia
- New Scientist: Cleaner Fish
- Florida Museum of Natural History: Shark Basics
- ReefQuest Centre for Shark Research: How Sharks Swim When Asleep
- National Geographic News Watch: Dolphins Sleep with Half their Brains
- United Nations – World Heritage: Great Barrier Reef
- Comstock Images/Comstock/Getty Images