Dalyellia viridis is a species of rhabdocoel flatworm in the family Dalyelliidae.[1]
The animal is usually colored intensively green due to zoochlorellae. It is 2.5 to 4 mm long[2] with a rounded anterior and pointed posterior end. It possesses a pair of kidney-shaped eyes.[3] Mature animals carry many eggs in their body.
It was described in 1791 by George Shaw as Hirudo viridis.
It occurs in freshwater in stagnant waterbodies. It is most frequently found in temporary pools.
The animal harbors symbiotic green algae (zoochlorellae) of the species Chlorella vulgaris in its body. It feeds on algae and animals, including microturbellarians.