Wild Animals A-Z

Invertebrates
Wild Animals A-Z »

INVERTEBRATES

Sponges, Coral and Jellyfish: There are around 5,000 species of sponge. These simple, primitive organisms are rooted to the ocean floor, where they filter food particles out of the water. Coral polyps are little more than a stomach, mouth and tentacles with which to capture food. They live in vast communities and excrete a calcium carbonate exoskeleton, which when joined together form coral reefs. These provide habitat to over one-quarter of all marine animal species. Jellyfish, like coral, possess stinging cells. When activated, a stinging cell injects immobilizing toxins into the victim through a long, spined tube.

Amazing Mollusks: The mollusks include the largest and most intelligent species of invertebrates on the planet. Octopuses, for example, have both short- and long-term memory, and may even have the capacity to learn. At up to 46 feet in length, the colossal squid is the world's largest invertebrate. Mollusks are characterized by their shells. Some shells, like those of the whelk, are large, elaborate and highly protective, while in orders like slugs and squid, only the vestigial remnants of a shell remain. Most of the 100,000 mollusk species live in the ocean, but some live in freshwater or, in the case of land snails and slugs, on land.

Jellyfish
The jellyfish: packing a very unfair amount of venom.

Octopus
When it comes to limbs, eight is enough for the octopus.
Squid
Launch the torpedos! Full squids ahead!