Various writers have suggested that ancient humans were contacted, or even created, by more advanced beings from another planet. It seems to me that such theories are more plausible if one substitutes the proposed alien with a visitor from the lands around Teleleli.
Babylonian myth tells of Oannes, who taught the human race writing, the arts and science. Oannes is said to have lived in the Persian Gulf, rising from the water during the day to instruct ancient humans.
The creature is described as having the body of a fish but underneath the figure of a man. This may mean that ‘he’ literally appeared as a hybrid of human and fish, like mermaids and mermen. But these creatures have little interest in learning, let alone teaching others. The reversed mer-folk, who have the upper parts of fish and the lower parts of humans, are more intellectual. But they would have great difficulty communicating with humans, being unable to speak or, due to their lack of arms, to gesture (they communicate amongst themselves by laying eggs of various types, the combinations of which are the ‘letters’ of their language). It may also refer to a human who came out of a ‘fish’ which was really a submarine. Finally, it may mean that the creature appeared to be a fish, but could communicate and reason, thus being human ‘underneath’.