These freshwater snails are endemic to Sulawesi in Indonesia, with the vast majority restricted to Lake Poso and the Malili Lake system (consisting of Matano and Towuti, and the smaller Lontoa (Wawantoa), Mahalona, Masapi).
They probably cannot live at an altitude above about 700 m.
Species
There were known 34 described species in 2005. Thomas von Rintelen with colleagues described 15 new species of Tylomelania in 2003-2008.
Tylomelania species diversification started in c. 5.4 Mya and was probably caused by the late Miocene and Plioceneorogeny.
Species within the genus Tylomelania include:
Tylomelania abendanoni (Kruimel, 1913)
Tylomelania amphiderita von Rintelen, Bouchet & Glaubrecht, 2007
Tylomelania bakara von Rintelen & Glaubrecht, 2003
Tylomelania baskasti von Rintelen & Glaubrecht, 2008
Tylomelania sinabartfeldi von Rintelen & Glaubrecht, 2008
Tylomelania solitaria [1]
Tylomelania tominangensis (Kruimel, 1913)
Tylomelania tomoriensis (Sarasin & Sarasin, 1898)
Tylomelania toradjarum (Sarasin & Sarasin, 1897)
Tylomelania towutensis (Sarasin & Sarasin, 1897)
Tylomelania towutica (Kruimel, 1913)
Tylomelania turriformis von Rintelen, Bouchet & Glaubrecht, 2007
Tylomelania wallacei (Reeve, 1860)
Tylomelania wesseli von Rintelen, Bouchet & Glaubrecht, 2007
Tylomelania wolterecki von Rintelen, Bouchet & Glaubrecht, 2007
Tylomelania zeamais (Sarasin & Sarasin, 1897)
Description
In species within this genus, the albumen gland is very large. Pallial oviduct evolved into an uterine brood (that release shelled juvenile snails).
Comparison of apertural views of shells of twenty Tylomelania species (images are not to scale):
Ecology
Species in the genus Tylomelania are ovoviviparous. Newly hatched snails of some species of Tylomelania measure nearly 2 cm and are the largest newly hatched viviparous gastropods.
