Claim: Adult Pseudocentrotus depressus liberate eggs and sperm into the water column and the echinopluteus larvae spend several months swimming and drifting with the plankton, a diverse collection of organisms unable to propel themselves.
Evidence: As is the case with most other sea urchins, the sexes are separate in this species, and adults liberate eggs and sperm into the water column. After fertilisation, the echinopluteus larvae spend several months swimming and drifting with the plankton. Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind).