Earthworms and cockroaches are both symbiotically related, though they do differ in some aspects. For example, the earthworm lacks a head, but it does have two sets of legs. Cockroaches are insects with a chitinous exoskeleton, while earthworms do not. The only feature that the two species share is a haemocoel, or tube that pumps blood between their organs.
Both earthworms and cockroaches have closed blood vascular systems, which means that their hearts pump blood in only one direction. The blood is supplied by smaller blood cells in the body wall and gut nerve cord. They also have blood glands in their fourth, fifth, and sixth segments that produce blood cells. These cells are phagocytic in nature. In contrast, cockroaches have Malphigian tubules, which are excretory organs.
Earthworms and cockroaches both have wings. Both insects have two pairs of wings (called elytra and mesothorax). Cockroaches do not fly, but they use them to escape danger. Their wings are not as large as those of a human, but they do have a broader range of motion than human wings.
Adaptation is a key factor in evolution, because it enables an organism to adapt to a particular environment. In the case of earthworms, most species share a similar shape, but their bodies have evolved to fit into different niches within their ecosystem. There are three main types of adaptations: structural adaptations, behavioural adaptations, and functional adaptations.