Light exposure on the regeneration of Dugesia dorotocephala IntroductionThe objective of this experiment was to test the effect of light exposure on the regeneration of Dugesia dorotocephala. Dorotocephala is a species belonging to the kingdom Animalia, class Turbellaria, order Seriata, these worms are classified in the suborder Tricladida based on the three main branches of their digestive system. They are further divided based on ecological habitat. They are available in freshwater, marine and terrestrial forms (Alvarado, Reddien). they belong to the Planariidae family and the Dugesia genus. These creatures exhibit bilateral symmetry and are classified as metazoans (eumetazoans). Dugesia is found in freshwater habitats in various regions of the world. They inhabit places in Africa, the Middle East, Europe, Asia and even parts of Australia. These small animals tend to be elongated with a triangular head. They have a dorsal surface covered in shades of grey, black and brown, and a ventral surface of a lighter shade than the dorsal part. In general they are small and have a soft body which allows them to hide in tight spaces. They are classified as free living and lack a coelom, blood system, and circulatory system. For this reason, many of their functions depend on diffusion. Freshwater turbellarians are benthic inhabitants of lakes, ponds, springs and streams. Their bodies are covered in cilia and possess a syncytial epidermis. These small animals lack appendages and rely on cilia to glide across surfaces. Unlike other worms, these freshwater flatworms are not segmented. They are acoelomate, meaning they lack a coelom or complete intestinal cavity. Their demonstration of bilateral symmetry has been linked directly to cephalization...... middle of paper ......neration in Planaria." Encyclopedia of Life Sciences (2001): page no. National Center for Biotechnology Information. US National Library of Medicine, nd Web. 18 March 2014. “Planaria: a window into regeneration.” Exploratorium, nd Web. 18 March 2014. “Planaria Regeneration Activities,” 2004. Web. 18 March 2014. .Zhenghou , Henan. “Identification of small noncoding RNAs in Dugesia Japonica planaria by deep sequencing.” Web. 18 March. 2014. .