The Greek word translated 'whale' means 'a sea monster.' The O.T. rendering is more accurate 'the fish’s belly' (Jon. 2:1), 'a great fish' (Jon. 1:17). It is scarcely needful to note that there are no whales in the Mediterranean…
THE KETEA (Cetea) were the monsters of the sea, the two greatest of which were the Ketos (Cetus) slain by Perseus in Aithiopia (Ethiopia) and the Ketos slain by Herakles at Troy.
Ketea were usually depicted as serpentine fish with long rows of sharp teeth. Nereides often appear riding side-saddle on the backs of these creatures. Ketos was also a generic word for any large sea-creature.