What does the fourth century fresco depicting the biblical story of jonah and the sea monster represent

The 4th Century Fresco of Jonah and the sea monster represents Christ’s death and resurrection.

Jonah was an Israelite who was commanded by God to go to a divine mission in Nineveh. He disobeyed and went on a sea voyage instead. In the Old Testament story, God raised a great storm which the sailors believed to be because of Jonah’s defiance. They threw Jonah overboard and was swallowed by a “great fish”. He stayed inside the fish for three days and was vomited on dry land. This is likened to how Jesus Christ died for three days after being crucified but raised from the dead and rose up to the heavens.