2. they are animal without backbone a vertebrates be in vertebrates c mammals d riptiled 3 which of the following is not are arthropods A. crabs B. scorpions C octopus D. insect 4. they are so soft-bodiedn animals with shell inside or outside their bodies called exoskeleton A. arthropods B.echinoderms C.poniferans 5. which of the following is not mollusks A.Spider B.snails C.clams D.spuids