According to the bible Jonah volunteered to be thrown overboard by his fellow travelers when a fierce storm threatened to overthrow their boat. God then created a great fih, who swallowed Jonah. Jonah spent three days and nights in the belly of the fish. Some negotiating went on as is the lords' wont, "And the LORD spake unto the fish, and it vomited out Jonah upon the dry land." (King James Bible from internet). Below the scene where Jonah is thrown into the grasp of the fish; to the left is the fish; above Jonah is beside the king of the city Nineveh (last part from Ataman Hotel site, which has good information on this church).
A viewer wrote: The first image in a circle (top, left) is Stephen Protomartyr ("Stephanos Nahavka"). The second circle depicts the prophet "Sophonias" or Zephaniah.