Palaemon affinis is a species of shrimp of the family Palaemonidae. Early authors used the name Palaemon affinis for specimens now known to belong to a variety of species, but P. affinis is now known to be endemic to the waters of New Zealand. Palaemon affinis are a cold blooded shrimp species found in New Zealand. They are invertebrate. They prefer lower light intensities, after they have ventured into light for a short period of time to warm up, they slink back into the darkness, to their preferred ecological niche. Their preferred temperatures are about 20 degrees celsius.