Okeanos and Tethys

Okeanos and Tethys, a 2nd-3rd c mosaic from a shallow pool in the House of Okeanos at Zeugma near Gaziantep. Okeanos is the river god - not an ocean but a river surrounding the world, the origin of life through the cycle of evaporation and rain. He has the tail of an eel and crab-claws on his head. Tethys is his wife.

Zeugma is supposedly the spot where Alexander crossed the Euphrates; it was founded by his general Seleucos I Nicator and subsequently flourished as a Roman city with a population of 80,000 and an area of 2,000 ha, and from which period the many mosaics date. Their conservation has been seriously compromised by thieves (though the thievery seems to have been what prompted interest in them in the first place, in the 1980s) and the Birecik Dam, which has put some of the site underwater. The Zeugma Museum in Gaziantep has all the recovered ones; some are at large and some are, presumably, underwater.

I didn't go to the site, unfortunately; this is in the museum.