Crayfish are invertebrates which means they don't have a backbone. They are also arthropods, which means that they have a protective exoskeleton on the outside of their body. Other arthropods include insects, spiders, and centipedes. Crayfish continually shed their exoskeleton and regrow a new one. During this transition is when they are most vulnerable to predators because they aren't protected by their outer shell.
Crayfish are found all over the world in many different freshwater environments, such as rivers, creeks, springs, and swamps. But this doesn't necessarily mean that you will be able to find them. They are somewhat cryptic because they dig out homes for themselves under rocks and blend in well with their environment. Crayfish will ardently defend this dwelling against intruders using their strong front claws
<span>The answer is nerve net.
Jellyfish has a nerve net that surrounds its
whole body. It makes a series of interconnected neurons that form net-like structure. This net surrounds the whole body of the jellyfish. Some jellyfish may have sensory structures, motor nerve net, and diffuse nerve net. Sensory structures receive environment signals and send them through diffuse nerve net to motor nerve net that activates muscle contractions.</span>
Answer:
explain please????!??????!
<span>The group of snails would represent the "population" level of ecological organization. A single snail would represent and Individual. The snails and beetles would represent a community, and the garden itself with the various creatures would represent and ecosystem.</span>