How long should a refrigerator last? This questions is asked so many time, again and again. Most refrigerator keep operational more than 10 years. A survey conducted by the appliance magazine found out that 80% of refrigerators last 8-14 years.
There are 5 main classes of mollusks, and two smaller classes that most people have never heard of. The principle classes are: Gastropoda (gastropods) - snails, slugs, conchs, whelks, cowries, etc. Bivalvia (bivalves) - clams, mussels, oysters, cockles, scallops, etc. just now. Report Abuse. The living mollusks are placed into seven classes (some workers combine the Solenogastres and Caudofoveata into a single class called Aplacophora): Solenogastres Caudofaveata Polyplacophora Scaphopoda Cephalopoda Bivalvia Gastropoda There are over 50,000 different types of mollusks alive today.
Not all mollusks have shells. Mollusks are a group of soft-bodied animals that includes snails, scallops, clams, and sea slugs. Most mollusks have shells: univalves, like snails, have one shell; bivalves, like clams, have two. Some mollusks, such as the squid and octopus, have lost their shells during their evolution. With 41% of the 736 documented extinctions of all animal species, the number of mollusks exceeds that of any other major taxonomic group 3. 2  Most documented endangered mollusk species are non marine (they live in freshwater or terrestrial environments) 5.