In molluscs,the respiratory pigment is

The phylum-$Mollusca$ lacks which one of the following?

Haemocyanin,the blue colouring pigment of molluscan blood,contains:

The study of molluscan shells is called ........

Open type of blood vascular system,presence of auricle and ventricle,and presence of haemocyanin respiratory pigment are the characters of

$A$ shell of calcium carbonate,a mantle,and a radula are characteristic features of which of the following?