In a reverse hierarchy, the conceptual pyramid of authority is turned upside-down, so that the apex is at the bottom and the base is at the top. This model represents the idea that members of the higher rankings are responsible for the members of the lower rankings.
Along the sides of the body is a light-colored horizontal stripe called the lateral line. The line is made up of a series of tiny pores that lead to receptors that are sensitive to the mechanical movement of water and sudden changes of pressure.The spiny dogfish has a double dorsal fin.The anterior dorsal fin is larger than the posterior dorsal fin.The spiny dogfish has the presence two spines, one immediately in front of each dorsal fin. The spines carry a poison secreted by glands at their base.he spiny dogfish has a double dorsal fin. The anterior dorsal fin is larger than the posterior dorsal fin. The spiny dogfish has the presence two spines, one immediately in front of each dorsal fin. The spines carry a poison secreted by glands at their base.
Examine the photographs of the dorsal wall of the body cavity of the male spiny dogfish shark by clicking the blue lettered links in the column to the right. The specimen in the phographs was prepared by removing almost the entire liver, alimentary canal, pancreas, and spleen.This revealed the urogenital structures: gonads, kidneys, and associated ducts. The urinary and genital systems have distinct and unique functions.abeled Ovaries. Examine the photographs of the female shark's oviducts by clicking the blue lettered links in the column to the right. The oviducts are elongated tube-like structures Iying dorsolaterally the length of the body cavity, along the sides of the kidneys. In mature specimens they are more prominent.