Authenticated (26/03/08) by Dr Juerg Brunnschweiler.
Dorsal fin: In fish, the unpaired fin found on the back of the body.
Ovovivipary: Method of reproduction whereby the egg shell is weakly formed and young hatch inside the mother; they are nourished by their yolk sac and then born.
Plankton: Aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).