Dorsal fin: in fish, the unpaired fin found on the back of the body.
Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
Pectoral fin: in fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.
Planktonic: aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).