2003/02/01 by Thomas von Rintelen, Matthias Glaubrecht · 7 citations
Agricultural and Biological Sciences · Environmental Science · #Aquatic Invertebrate Ecology and Behavior #Marine Bivalve and Aquaculture Studies #Mollusks and Parasites Studies
paper · pdf · doi:10.1093/mollus/69.1.3
openalex publication_date 2003/02/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
Lakes provide ideal natural laboratories for the study of evolutionary processes. Research on an assumed adaptive radiation of a species flock of viviparous freshwater gastropods in the Malili lake system on Sulawesi, Indonesia, known for a century, led to the unexpected discovery of new taxa. Three new species of Tylomelania Sarasin & Sarasin, 1897, T. bakara n.sp., T. kruimeli n.sp. and T. helmuti n.sp., are described based on their easily recognizable and distinct shell morphologies. Unique combinations of radular and embryonic shell characters support their status as distinct species. Two of the new species are lacustrine: T. bakara is restricted to a single location with a specific substrate and habitat in Lake Towuti, while T. kruimeli is distributed throughout Lake Mahalona. In contrast, T. helmuti is fluviatile and occurs in a stream system draining into Lake Towuti. The discovery of new species within the species flock under investigation is surprising, since the range of forms seemed known and, after preliminary studies, even a reduction in the number of species recognized as valid was expected. This example highlights the importance of extensive and systematic collecting even on a rather small geographical scale for studies on the phylogeny and evolutionary biology of freshwater gastropods.