 The lake drains into the Poso River at Tentena, which flows into the Molucca Sea at the town of Poso.The lake contains various fish, including the eel "Anguilla marmorata" which migrates between the lake and the sea, and 11 fish species that are endemic to the lake, notably buntingi ricefish ("Adrianichthys", "Oryzias nebulosus", "O. nigrimas" and "O. orthognathus"), gobies ("Mugilogobius amadi" and "M. sarasinorum"), and the halfbeak "Nomorhamphus celebensis".These endemics are all highly threatened; in some cases possibly already extinct.