Jellyfish jellyfish, because jellyfish feed on plankton, which includes fish eggs and larvae. Jellyfish form a component of jelly-falls, events where gelatinous zooplankton fall to the seafloor, providing food for the benthic organisms there. In temperate and subpolar regions, jelly-falls usually follow immediately after a bloom. Most jellyfish are marine animals, although a few hydromedusae inhabit freshwater. The best known freshwater example is the cosmopolitan hydrozoan jellyfish, "Craspedacusta sowerbii". It is less than an inch (2.5 cm) in diameter, colorless and does not sting. Some jellyfish populations have become restricted to coastal saltwater lakes, such as Jellyfish Lake in Palau. Jellyfish
Freshwater crab where the eggs hatch as juveniles, with the larval stages passing within the egg. The broods comprise only a few hundred eggs (compared to hundreds of thousands for marine crabs) each of which is quite large, at a diameter of around . The colonisation of fresh water has required crabs to alter their water balance; freshwater crabs can reabsorb salt from their urine, and have various adaptations to reduce the loss of water. In addition to their gills, freshwater crabs have a "pseudo-lung" in their gill chamber that allows them to breathe in air. These developments have pre-adapted freshwater crabs