Gdz Biologiia 7 Sumatokhin Klass Dvukhstvorchatye Molliuski May 2026

: Species like oysters, mussels, and scallops are important food sources for humans and marine life.

: The body is laterally compressed and divided into two main parts: the trunk and the wedge-shaped foot . Unlike gastropods, bivalves lack a head, tentacles, and eyes. gdz biologiia 7 sumatokhin klass dvukhstvorchatye molliuski

: Swan mussels ( Anodonta ), thick-shelled river mussels ( Unio ), and giant clams ( Tridacna ). : Species like oysters, mussels, and scallops are

Mouth (near the foot), stomach, liver, and intestine. They lack a radula (grating tongue). Plate-like gills (ctenidia) located in the mantle cavity. Excretory Two kidneys that open into the mantle cavity. Nervous Simplified, consisting of three pairs of ganglia. Ecological and Economic Importance : Species like oysters

: Consists of two symmetrical valves connected by a flexible ligament and a "lock" (hinge).