Hi Leonard and Everyone
Last month I posted a question here about nerite snails such as
Clithon corona, asking if anyone could confirm their locations and breeding habits. None of us were completely sure. However, in the meantime I managed to contact an American who is an expert on this snail family (Neritidae) and have got some reliable information.
Clithon corona,
Vittina coromandeliana (the striped or tiger nerite),
V. semiconica (the spotted or ruby nerite), and
Septaria porcellana (the freshwater limpet) are widespread throughout the Indo-Pacific region (with the exception of
V. semiconica, which is confined to Indonesia). All of these snails generally live in freshwater as adults and feed on diatomaceous algae. They lay white eggs below the waterline on any hard surface. Numerous veligers (larvae) hatch from these eggs and are swept downstream to the ocean. Here they spend some time growing, and once they have developed into tiny snails they crawl back inland to live in the habitats of their parents. Most adult nerites are found in rivers and irrigation canals, where they can be present in large numbers and are collected for food or the beauty of their shells (and presumably to be sold to aquarists as well!).
Leonard, as I understand it, the main problem with breeding these snails is not adjusting the salinity, but feeding the young. The larvae spend some time at sea, where it is believed they feed on plankton. The expert I spoke to did not think that it was feasible for anyone to breed these snails in captivity
The only nerites that can be easily bred are those that have direct development, which means that the eggs hatch to give a tiny, fully-formed snail and not a veliger. One of the members on this site (Allex) breeds the European nerite,
Theodoxus fluviatilis, in this way.
Hope this helps,
Anna