In the last years with the flourishing of the WSN (wireless sensor network) paradigm, ignited by DARPA funded UC Berkeley "Smart Dust" project, the monitoring and exploration of the terrestrial enviroment has greatly improved. The acquatic world, which covers more than the 70% of the earth, instead, has been largely unaffected by the WSN revolution due to the difficulty of transferring most of the know-how developed for terrestrial and aerial systems and devices to their underwater counterparts. The aim of this article is to propose a new generation of UWSN (underwater wireless sensor network), called Smart Plankton, by drawing inspiration from marine biology and acquatic micro-organisms. Our focus is on network node individual body, communication link among devices, energy scavenging and production and swarm intelligence.