Obtain a preserved starfish and rinse off any preservative with water. Place the starfish in the dissecting pan with its dorsal or aboral (top) surface upward. Observe the starfish and determine its symmetry. Locate the central disc in the center of the starfish.Count and record the number of arms or rays the starfish has. Locate the small, round hard plate called the madreporite on top of the central disc. Water enters through this into the water vascular system. Label the central disc, arms, and madreporite on Figure 1.btain a preserved starfish and rinse off any preservative with water. Place the starfish in the dissecting pan with its dorsal or aboral (top) surface upward. Observe the starfish and determine its symmetry. Locate the central disc in the center of the starfish.
History. The third largest city in France, Lyon is situated in the Rhone-Alpes region between Paris and Marseille. A UNESCO World Heritage site, the city is home to roughly 490,000 inhabitants and was prized in ancient times as a major centre for the production and sale of silk.istory. The third largest city in France, Lyon is situated in the Rhone-Alpes region between Paris and Marseille. A UNESCO World Heritage site, the city is home to roughly 490,000 inhabitants and was prized in ancient times as a major centre for the production and sale of silk.
The climate of Lyon (France) The agglomeration of Lyon is the largest town of France except Paris and the most important town of the Rhne district.