it isn't
The telson is used as a paddle when alarmed to put distance between crayfish and prey. The crayfish makes a rapid movement of its tail which helps it to move backwards swiftly.
no animal can walk backwards, they don't have legs!!
Use its tail to swim backwards at high velocity.
Lobsters are saltwater and crayfish (crawdads) are freshwater.
I live in New Rochelle, New York and I have recently seen many crayfish migrating away from Glenwood Lake and being killed by the dozens on an adjacent road. Why is this and where are they trying to go?
There is nothing different
They are both invertebrates.
They are shellfish, they have an exoskeleton.
It helps them maintain their balance under water, and allows them to swim backwards swiftly when frightened or running from predators.
A car model that is spelled the same forward and backwards is a race car. As you can see RACECAR backwards is RACECAR.
The word is palindrome. For example “Madam” is the same read backwards or forwards.
A uropod is used for swimming. Telson does the same thing.