Information authenticated by Jean-Luc Solandt of the Marine Conservation Society:
www.mcsuk.org
Bivalve: in this group of aquatic molluscs the soft parts are encased in a shell consisting of two parts known as 'valves'.
Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
Planktonic: aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).