sentences:  The deep Mediterranean has a relatively constant temperature of and a salinity of 38.4 ppt, whereas in the deep ocean the temperature is generally only and the salinity 34–35 ppt.The Portuguese dogfish is essentially benthic in nature, though young sharks can be found a considerable distance off the bottom.There is depth segregation by size and sex; pregnant females are found in shallower water, above , while juveniles are found deeper.