Linear density. Linear density is the measure of a quantity of any characteristic value per unit of length. Linear mass density (titer in textile engineering, the amount of mass per unit length) and linear charge density (the amount of electric charge per unit length) are two common examples used in science and engineering.
Gastrovascular system of the flatworm Dugesia, colored yellow. The gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Cnidaria (including jellyfish and corals) and Platyhelminthes (flatworms). The cavity may be extensively branched into a system of canals.In cnidarians, the gastrovascular system is also known as the coelenteron, and is commonly known as a blind gut or blind sac, since food enters and waste exits through the same orifice.astrovascular system of the flatworm Dugesia, colored yellow. The gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Cnidaria (including jellyfish and corals) and Platyhelminthes (flatworms). The cavity may be extensively branched into a system of canals.
Most members of the Cnidaria phylum live in marine habitats, but some including jellyfish, are known to live in freshwater habitats. The members of the Cnidaria phylum are divided into two distinct categories based on their eating habits-they are either carnivorous or they are filter feeders.