Gape: The mouthline of a cetacean.
Gulp feeding: A feeding technique performed by, mainly, roquals thrusting forward with open mouths and taking in a large quantity of prey.
Herd : A co-ordinated group of cetaceans (term is most often
used when referring to baleen whales).
Homocercal Fin : A caudal fin with lobes of about the same size.
Infrasound: Sound produced below human hearing or 20 Hertz.
IWC: International Whaling Commission. An international body
formed in 1946 to regulate whaling and conserve whale stocks - also see (what
is the IWC)