Is an arthropod warm blooded or cold blooded?

Answer 1

Cnidarians do not have a circulatory system. Different parts of the body receive nutrients not via a stream of blood but through diffusion from seawater into their tissues. They are neither cold, nor warm-blooded - they have no blood.

Answer 2

Arthropods are called cold-blooded as they largely depend on their environment for heat; such as basking in the sun, etc. As such they are called partially ectothermic. "Partial" because some employ mechanisms which generate heat; such as flying insects like moths and bees which vibrate their wings prior to takeoff to heat one of their body segments. Some flying insects also employ convective, evaporative and possibly heat-exchange thermal regulation methods.