anatomy of a bivalve shell![click to hear](/images/speaker.jpg)
shell ![click to hear](/images/speaker.jpg)
Calcareous casing produced by the mantle; it has three layers and protects the main organs of the mollusk.
ligament ![click to hear](/images/speaker.jpg)
Corneous structure located behind the umbones and joining both valves of the shell; its elasticity allows them to pull apart.
umbo ![click to hear](/images/speaker.jpg)
Protuberance at the terminal end of the valve, from which the shell grows.
mantle ![click to hear](/images/speaker.jpg)
Thick fold of tissue forming two lateral lobes; it envelops the organic mass of the mollusk and secretes its shell.
intestine ![click to hear](/images/speaker.jpg)
Section of the digestive tract between the stomach and the anus where absorption of nutrients is carried out and waste is transformed into fecal matter.
cerebropleural ganglion ![click to hear](/images/speaker.jpg)
Small sac located near the anterior abductor muscle; the nervous system is made up of three pairs of ganglia (cerebropleural, visceral and pedal).
visceral ganglion ![click to hear](/images/speaker.jpg)
Small sac located near the posterior abductor muscle; the nervous system is made up of three pairs of ganglia (cerebropleural, visceral and pedal).
anus ![click to hear](/images/speaker.jpg)
Terminal orifice of the digestive tract enabling ejection of fecal matter.
posterior adductor muscle ![click to hear](/images/speaker.jpg)
Powerful muscle attached to both inside surfaces of the valves; it contracts to open or close them quickly.
kidney ![click to hear](/images/speaker.jpg)
Organ secreting urine; it eliminates toxic substances from the body.
heart ![click to hear](/images/speaker.jpg)
Muscular organ helping blood to circulate.
digestive gland ![click to hear](/images/speaker.jpg)
Organ producing a secretion that contributes to digestion.
stomach ![click to hear](/images/speaker.jpg)
Dilated section of the digestive tract preceding the intestine; it receives food to be digested.
anterior adductor muscle ![click to hear](/images/speaker.jpg)
Muscle attached to both inside surfaces of the valves that contracts to open or close them quickly; it is less powerful than the posterior abductor muscle.
labial palp ![click to hear](/images/speaker.jpg)
Mouthpart that grasps food particles deposited on the gills and carries them to the mouth.
mouth ![click to hear](/images/speaker.jpg)
Anterior cavity of the digestive tract surrounded by four labial palps, which enable food particles to enter.
gonad ![click to hear](/images/speaker.jpg)
Genital gland producing spermatozoa (sperm) or ova (eggs), depending on the sex of the mollusk.
gills ![click to hear](/images/speaker.jpg)
Respiratory organs located between the foot and the mantle, formed of two layers of ciliated filaments, which filter water and retain food particles.