E. complanata generally attains an average adult length of 120 – 150mm, with anecdotal measurements extending to 500mm (Mendez and Paez-Osuna, 1998). During locomotion, this polychaete was observed to elongate to nearly double its ‘resting’ length (Figure 1).
There is no primary literature pertaining to E. complanata’s growth rates, size at sexual maturity, and size at sex change or if feeding/behaviors change with size.
 
Figure 1. A time lapse of the same E. complanata and its elongation potential whilst moving. |