Eunice aphroditois

Eunice aphroditois has a hard exoskeleton covering its body.[10] The largest known specimen on record reached 299 centimetres (9.81 ft) in length.[1] Despite these great lengths, these worms are quite slim with width of the body only about 1 inch (2.5 cm) across the back. These ambush predators have two eyes and five antennae on their head that are used to sense prey when hunting in soft sediments.[11] The mandibles are responsible for striking and stunning its prey and are capable of snapping some in half.[12] Typically, E. aphroditois color ranges from deep purple to black along with metallic color as well. The fourth antenna is always white.[13]

This species has been found in the mainly warmer parts of select bodies of water such as Indonesian and European waters.[12] They are often found prowling among coral reefs due to their ability to blend in and hunt in very tight places because of their slim body.[12] This also goes along with the abundance of marine life that lives in these reefs that they prey on. They also have a relatively wide range of habitats.[14] The species spends most of their time in sandy and muddy sediments as well as around rocks and sponges.[12] Among the greatest depths, the bobbit worm has been recorded to live on the seas floor at ten to ninety-five meters.[7]

It is believed the lifespan of E. aphroditois is relatively short, ranging from three to five years in age.[16] Their life cycle starts when conceived after spawning. Their eggs are often eaten or destroyed by other organisms. Parents take little or no responsibility for raising their offspring.

Most of the class Polychaeta are benthic sexual reproductive animals[17] and lack external reproductive organs. When mating, female polychaetes produce a pheromone that attract the male species to automatically release sperm and when this takes place, in return it then also allows females to give away eggs into the water.[7] They use a technique called "broadcast fertilization" or "spawning", which means the males and females eject their sperm and eggs into the open water to fertilize and colonize within their environments. There is no need for contact between the males and females during this action for fertilization to occur.[7]