Mollusca
- This phylum is composed of 85,000 invertebrate and soft bodied species.
-The mollusca is the largest acquatic phylum.
-The mollusca species are highly diverse in structure, behavior, etc.
-The Mollusca phylum is derived from the Platyhelminthes phylum.
-Three animals are: snails, oysters, and octopus
-The mollusca is the largest acquatic phylum.
-The mollusca species are highly diverse in structure, behavior, etc.
-The Mollusca phylum is derived from the Platyhelminthes phylum.
-Three animals are: snails, oysters, and octopus
Snails
Snails, having thin skin permeable for water, are capable of breathing through their skin but are also exposed to losing water through their skin. Aside from their skin, snails use gills to breathe. Their gills are responsible for taking oxygen from water and releasing carbon dioxide back into it. Ancient snails had 2 sets of gills, but over time this number was reduced to 1.
Octopus
An octopus is made up of eight legs that connect to a mantle. To breathe, the octopus gets oxygen when water is taken into the mantle. The water provides the gills with oxygen and is then released through the siphon tube. The gills recieve blood from the gill hearts. Once blood reaches the gills, the blood takes in oxygen from the water. The new oxygen filled blood is pumped to the systematic (third) heart, which then pumps blood to the rest of the body. An octopus's respiratory system is unique because it combines with the circulatory system to get oxygen and blood throughout the body.
Oysters
Lying on the mantle of an oyster, there is a series of plates. These plates act as the the gills. These gills take in water and use the oxygen. When oxygen is taken into the blood, it is passed to the heart. Once in the heart, the oxygen filed blood is distribued throughout the oyster. The water that had the oxygen taken from it is passed through the anus and is released out of the shell.