Most animals and plants are part of more than one food chain. If one part of a food chain alters, the whole food chain is affected. For example, if a disease suddenly wiped out caterpillars, it would affect mice, owls and many other animals.
This phylum consists of the jellyfish, hydra, sea anemones, corals, sea pens, sea wasps, and box jellyfish. There are about 9,000 species. Almost all are marine. This is another ancient group, with fossils perhaps reaching back to 700 mya.
Mollusks. The phylum Mollusca is the largest and most diverse phylum of animals next to arthropods. Mollusks can be found in nearly every ecosystem on earth, from high, barren mountains to grassy plains, lakes, rivers and in all seas and oceans.ollusks. The phylum Mollusca is the largest and most diverse phylum of animals next to arthropods. Mollusks can be found in nearly every ecosystem on earth, from high, barren mountains to grassy plains, lakes, rivers and in all seas and oceans.