Water flea morphs. Coloured scanning electron micrograph (SEM) of stages in the development of two differently-shaped forms of the water flea Daphnia cucullata. Research at the Ludwig- Maximilians University, Germany has shown phenotypic plasticity in water fleas; they change their body shapes in response to chemicals (kairomones) given off by predators. The morph at bottom is a standard shape, whilst that above it has a long helmet (pointed) and tail (spike), which may make it difficult for invertebrates to catch or eat it. This flea's predators include the phantom midge Chaoborus sp. and the giant water flea Leptodora sp.. Magnification unknown.