2/1/2024 0 Comments Do sponges have legs to move![]() Later, as they were studied more, sponges came to be considered "zoophytes" or plant-animals. ![]() ![]() Early naturalists considered sponges to be plants since they looked like a plant and did not move. The sponge is the simplest of all invertebrates (and therefore the simplest of all animals) and lives at the bottom of the sea. Invertebrates are often considered to be pests, yet despite our best efforts to exterminate them, they seem to adapt and thrive. Invertebrates not only live almost everywhere on Earth, but range in size from an organism too small to be seen without a microscope to a giant squid measuring 60-feet (18.29 meters). ![]() This gives some sense of how successful these "lower" animals have been in the race for survival. The animal kingdom is divided into major groups called "phyla," (singular, phylum), and of all the animal phyla identified (some say there are as many as thirty-eight), only one includes vertebrates. In nature there is no actual dividing line that separates animals with backbones from those without one, but grouping the members of the kingdom Animalia in this manner allows biologists to sort them into very broad groupings. An invertebrate may be as soft as a jellyfish or as hard as a lobster but they have one distinction in common-they have no bony vertebral column or backbone. They inhabit nearly every type of environment on Earth and vary greatly in the way they live and reproduce. Of the roughly 1,500,000 different species of animals in the world, more than 95 percent are invertebrates. ![]() Within this seemingly simple grouping there is an amazing variety of complex life forms: from sponges and starfish to earthworms, clams, spiders, and butterflies. An invertebrate is a multicelled animal that does not have a backbone. ![]()
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