Physiology-
Reproductive system-
Since the phylum Mollusk spans over a large amount of different species, Mollusks sometimes reproduce sexually, and sometimes asexually. When Mollusks reproduce sexually,
Gonads (organs found in Mollusks) send out sperm or ova which then go to the Coelom, a cavity surrounding the heart. After the gametes are in this cavity, nephridia (other organs) extract them, and bring them to the mantle cavity, which is where they are fertilized, or where they actively fertilize.
Nervous System-
Mollusks normally have two pairs of nerve cords (4 in all) (three pairs found in Bivalve Mollusks). All of the nerve cords go beneath the gut. The brain (which corresponds to these nerve cords) surrounds the esophagus. A majority of Mollusks have heads with eyes. All Mollusks have tentacles that have sensors, located on the head. The tentacles can detect touch, vibrations, and chemicals.
Respiration-
Mollusks ordinarily possess a pair of gils, while sometimes they only have one gill. Their mantle cavities are divided in a way that enables water to enter near the bottom and leave near the top. The filaments in their gills have three different kinds of cilia. One of the types of cilia brings the water through the mantle cavity, and the other two types
help keep the gills clean.
Reproductive system-
Since the phylum Mollusk spans over a large amount of different species, Mollusks sometimes reproduce sexually, and sometimes asexually. When Mollusks reproduce sexually,
Gonads (organs found in Mollusks) send out sperm or ova which then go to the Coelom, a cavity surrounding the heart. After the gametes are in this cavity, nephridia (other organs) extract them, and bring them to the mantle cavity, which is where they are fertilized, or where they actively fertilize.
Nervous System-
Mollusks normally have two pairs of nerve cords (4 in all) (three pairs found in Bivalve Mollusks). All of the nerve cords go beneath the gut. The brain (which corresponds to these nerve cords) surrounds the esophagus. A majority of Mollusks have heads with eyes. All Mollusks have tentacles that have sensors, located on the head. The tentacles can detect touch, vibrations, and chemicals.
Respiration-
Mollusks ordinarily possess a pair of gils, while sometimes they only have one gill. Their mantle cavities are divided in a way that enables water to enter near the bottom and leave near the top. The filaments in their gills have three different kinds of cilia. One of the types of cilia brings the water through the mantle cavity, and the other two types
help keep the gills clean.