Yukkuris that make their home on or inside water. Most of them are immune to water's usually fatal effects on yukkuris, with aquatic marisas being an exception
As yukkuris are weak against salt, in most stories aquatic yukkuris are a freshwater species and lives on lakes and rivers or owned by humans in a fishbowl.
Their immunity to water, ease of breeding (as with most yukkuris) and being a favored meal by most fishes makes them a popular bait for fishers
Examples include aquatic marisas, nitoris, and shell marisas (only in some canons)