[Kristoffer O]

Dagon is likely a distortion of the west-semitic god Dagan, a fertility diety, and in several texts father of Ba'al. Etymologically Dagan means grain. The fact that dag means fish is probably the reason he later on become considered a fish god. Since there are few sources on dagan, and none which states his function it is up to us to speculate.

The first fish-man of the paintings could be any divinity associated with water including a possible fish-dagon. The latter of the two is from Nineveh, and by all accounts not the philistine Dagon.