Piscis Austrinus or Piscis Australis (both of which are Latin for Southern Fish) was one of the 48 constellations listed by Ptolemy, and is also one of the 88 modern constellations. Its only bright star is Fomalhaut.
Mythology
It is thought that originally, Piscis Austrinus was the only constellation thought of as a fish, Pisces becoming considered a fish only later.
See Also