This is a list of every known public mailing list concerned somehow with aquaria and or tropical fish, plants, their care and feeding. There are a few here that aren't strictly about aquaria but are concerned with ichthyology or oceanography which are still of use and interest to aquarists.
Aquatic plants have their own following and are grouped here.
Mailing lists about live foods are grouped here. There are many mailing lists that focus on a specific species of fish such as Discus or groups of fishes such as Apistogramma dwarf Cichlids, or Killifish. Not hobbyist related These lists are for scientific research and discussion. This is not the place to ask why your water turned green. The lists here are of general interest and of a very broad nature about the general guidelines and principles of aquarium maintenance.