I have already referred to Marduk; he is the Spring Sun-God, and it has also been stated that the greatest god of ancient Babylonia, Ía of Eridu, was connected with the constellation of Capricornus.
Marduk represented the constellation of the Bull. Here I quote Jensen:—[177]
"It has already been suggested that the Bull is a symbol of the Spring-Sun Marduk; that he was originally complete; that he at one time extended as far as the Fish of Ía, i.e. the western Fish; that the Fish of Ía, out of which the sun emerged at the end of the year in ancient times to enter Taurus, is to represent Ía, the God of the Ocean, out of which his son Marduk, the early sun, rises daily; finally, that a series of constellations west of the Fish(es) is intended to represent symbolically this same ocean. Marduk is on the one hand, as early sun of the day (and the year), the son of Ía, the god of the world-water."
As to the sun-god Marduk, then, he represents the sun at the vernal equinox, when the sunrise was heralded by the stars in the Bull.
But what, then, are the fish of Ía and the other constellations referred to? They are all revealed to us by the myth. They are the Southern ecliptic constellations.
Tiāmat.
Tiāmat, according to Jensen, means initially the Eastern Sea (p. 307). This was expanded to mean the "Weltwasser" (p. 315), which may be taken to mean, I suppose, the origin of the Greek ὠκεανὸς, and possibly the overlying firmament of waters. These firmamental waters contain the southerly ecliptic constellations, the winter and bad-weather signs—the Scorpion, the Goat-fish, and the Fish among them.
It must be pointed out that these southerly constellations were associated with the God of Eridu in his first stage.
The Constellations referred to in the Myth of Marduk and Tiāmat.
We are indebted to the myth, then, for the knowledge that when it was invented, not only the constellations Bull and Scorpion, but also the Goat and Fishes had been established in Babylonia.