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
It helps with the optic nerve, if you give me options i can help answer. Sorry if I didnt help :)
Answer: sneezing or coughing over the evidence, direct sunlight on transport an storage
Explanation:
DNA evidence is contaminated when DNA from an outside source (exogenous DNA) gets mixed with DNA relevant to the case. It can happen in a variety of ways, from someone sneezing or coughing over the evidence,
High power if your using a light microscope. Hope this helps.
