Distribution map of Tylomelania (red area) cover the majority of Sulawesi. Grey area with dashed line is showing Wallacea.
Tylomelania are endemic to Sulawesi in Indonesia,[2] 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).[6]
They most likely cannot inhabit altitudes above roughly 700 m (2,300 ft).[5]
Species
There were known 34 described species in 2005.[2] 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.[5]
In species within the genus, the albumen gland is very large.[2] The pallial oviduct evolved into a uterine brood, which releases shelled juvenile snails.[2] Compared to other aquatic snails, many species of Tylomelania are known to be the few groups of snails that are not hermaphroditic but rather dioecious.[9]
Comparison of apertural views of shells of twenty Tylomelania species are below, though are not of proper scale:
Species in the genus Tylomelania are ovoviviparous.[2] Newly hatched snails of some species of Tylomelania measure nearly 2 cm (0.79 in) and are the largest newly hatched viviparous gastropods.[2]
^ abcdefghijklvon Rintelen, Bouchet P. & Glaubrecht M. (2007). "Ancient lakes as hotspots of diversity: a morphological review of an endemic species flock of Tylomelania (Gastropoda: Cerithioidea: Pachychilidae) in the Malili lake system on Sulawesi, Indonesia". Hydrobiologia592:11–94. doi:10.1007/s10750-007-0765-8.
^ abcdvon Rintelen T. & Glaubrecht M. (2008). "Three new species of the freshwater snail genus Tylomelania (Caenogastropoda: Pachychilidae) from the Malili lake system, Sulawesi, Indonesia". Zootaxa1852: 37–49. PDF.
^ abcdvon Rintelen T., Stelbrink B. Marwoto R. M. & Glaubrecht M. (2014). "A Snail Perspective on the Biogeography of Sulawesi, Indonesia: Origin and Intra-Island Dispersal of the Viviparous Freshwater Gastropod Tylomelania". PLoS ONE9(6): e98917. doi:10.1371/journal.pone.0098917.
^von Rintelen T., von Rintelen K. & Glaubrecht M. (2010). "The species flock of the viviparous freshwater gastropod Tylomelania (Mollusca: Cerithioidea: Pachychilidae) in the ancient lakes of Sulawesi, Indonesia: the role of geography, trophic morphology and colour as driving forces in adaptive radiation." pp. 485–512 in: Glaubrecht, M. & Schneider H. eds. (2010). Evolution in Action: Adaptive Radiations and the Origins of Biodiversity. Springer Verlag, Heidelberg, Germany.
^ abcvon Rintelen T. & Glaubrecht M. (2003). "New discoveries in old lakes: three new species of Tylomelania Sarasin & Sarasin, 1897 (Gastropoda: Cerithioidea: Pachychilidae) from the Malili lake system on Sulawesi, Indonesia". Journal of Molluscan Studies69(1): 3–17. doi:10.1093/mollus/69.1.3
Wikimedia Commons has media related to Tylomelania.
von Rintelen T., Wilson A. B., Meyer A. & Glaubrecht M. (2004). "Escalation and trophic specialization drive adaptive radiation of freshwater gastropods in ancient lakes on Sulawesi, Indonesia". Proceedings of the Royal Society B271: 2541–2549. doi:10.1098/rspb.2004.2842.
