Temperature has an influence on phenotypic plasticity, an important adaptive mechanism in rotifers . Several studies stated that low temperature can cause a morphological change in rotifers . In addition, the presence of predator (Asplanchna girodi) and low food levels can induce lorica and spine elongation in brachionid rotifers . Temperature also has an effect on fecundity and life span of Temperature, Population Dynamics and Spine-Length brachionid rotifers