Class Bivalvia
Bivalves or Two valves are the second largest molluscan class. It includes clams, oysters, mussels, and scallops. Most bivalves are edible, some are even able to produce pearls. These organisms are also especially important to the ecosystem. Due to them being filter feeders removing bacteria from polluted water.
On the exterior of a bivalves' shell is a somewhat swollen area, this is the eldest of the parts of a bivalve called the umbo. The bivalve also has Adductor muscles, used to keep the shell closed they have proved themselves to be very useful considering anyone who'd try to force a bivalve open would come up with no luck, This is a bivalves' primary form of defense against sea stars.
Bivalves are usually sedentary, and have adapted to it with the loss of its head and radula with few exceptions.
Bivalves obtain nourishment from food grooves, which essentially the food particles are trapped inside the clam with the assistance of the gills, then are moved via cilia to the grooves then from there to the mouth. Labial palps also aid in sorting the food particles.
Digestion in a bivalve is done with the help of to structures, the crystalline style is used to project into the style sac. The gastric shield with its acidic conditions releases enzymes. As food winds around the crystalline style it rotates, pulling food farther into the stomach away from the esophagus, with this happening and the acidic pH of the stomach dissolves food particles.
All bivalves have an Open circulatory system, with active blood flow from the heart to tissue, nephridia, gills and back to the heart. As for a bivalves nervous system it only consists of three interconnected ganglia which are also associated with the esophagus, foot, and adductor muscles, They also have sensory cells and photoreceptors. In scallops their photoreceptors are complex eyes lens and cornea.
Mostly all Bivalves are dioecious and some are monoecious, their gonads are located in the visceral mass. these organisms undergo external fertilization in which the gametes exit through the suprabranchial chamber of the the mantle cavity and an excurrent opening
In developement a bivalve will go through both the trochophore and veliger stage, once the veliger stage is complete and the organism burrows into the substrate it will be in its adult form. While in its trochopore and veliger stages some mothers bring up their young in its gills, others bring up their young in a "modified" veliger stage which is called glochidium which is also parasitic on fishes.
Bivalves all mostly in habit aquatic areas, usually burrowed in mud or sand. Most land dwelling bivalves attach to its substrate with proteinaceous strands or byssal threads.
Boring bivalves are able to live under limestone, clay, coral, wood, and many other substrates. Boring is where the larva settles to the substrate ,and the anterior end of the valve abrades the substrate.
On the exterior of a bivalves' shell is a somewhat swollen area, this is the eldest of the parts of a bivalve called the umbo. The bivalve also has Adductor muscles, used to keep the shell closed they have proved themselves to be very useful considering anyone who'd try to force a bivalve open would come up with no luck, This is a bivalves' primary form of defense against sea stars.
Bivalves are usually sedentary, and have adapted to it with the loss of its head and radula with few exceptions.
Bivalves obtain nourishment from food grooves, which essentially the food particles are trapped inside the clam with the assistance of the gills, then are moved via cilia to the grooves then from there to the mouth. Labial palps also aid in sorting the food particles.
Digestion in a bivalve is done with the help of to structures, the crystalline style is used to project into the style sac. The gastric shield with its acidic conditions releases enzymes. As food winds around the crystalline style it rotates, pulling food farther into the stomach away from the esophagus, with this happening and the acidic pH of the stomach dissolves food particles.
All bivalves have an Open circulatory system, with active blood flow from the heart to tissue, nephridia, gills and back to the heart. As for a bivalves nervous system it only consists of three interconnected ganglia which are also associated with the esophagus, foot, and adductor muscles, They also have sensory cells and photoreceptors. In scallops their photoreceptors are complex eyes lens and cornea.
Mostly all Bivalves are dioecious and some are monoecious, their gonads are located in the visceral mass. these organisms undergo external fertilization in which the gametes exit through the suprabranchial chamber of the the mantle cavity and an excurrent opening
In developement a bivalve will go through both the trochophore and veliger stage, once the veliger stage is complete and the organism burrows into the substrate it will be in its adult form. While in its trochopore and veliger stages some mothers bring up their young in its gills, others bring up their young in a "modified" veliger stage which is called glochidium which is also parasitic on fishes.
Bivalves all mostly in habit aquatic areas, usually burrowed in mud or sand. Most land dwelling bivalves attach to its substrate with proteinaceous strands or byssal threads.
Boring bivalves are able to live under limestone, clay, coral, wood, and many other substrates. Boring is where the larva settles to the substrate ,and the anterior end of the valve abrades the substrate.