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.
The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to large. There are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpets, land snails and land slugs.The class Gastropoda contains a vast total of named species, second only to the insects in overall number.The fossil history of this class goes back to the Late Cambrian.There are 611 families of gastropods known, of which 202 are extinct and appear only in the fossil record.owever, eyes in gastropods range from simple ocelli that only distinguish light and dark, to more complex pit eyes, and even to lens eyes. In land snails and slugs, vision is not the most important sense, because they are mainly nocturnal animals.