Final answer:
Invertebrates like jellyfish, spiders, and crabs are predators, which means they actively hunt and feed on other animals.
Step-by-step explanation:
When we say invertebrates like jellyfish, spiders, and crabs are predators, it means they feed on other animals. Predation involves actively hunting or capturing prey for food. This is in contrast to other feeding methods such as filter feeding, scavenging, or grazing on plants. Jellyfish, for example, may use their tentacles to capture small fish or plankton, while crabs can use their claws to catch and consume a variety of organisms, illustrating the predatory behavior of these invertebrates.