Question

in which group ventral muscular foot is present?​

Answer 1

Phylum Mollusca is characterised by the pronounced development of musculature known as the foot. It is the locomotory organ in Molluscs. This organ is quite uncommon and strange to others. It is regarded as the remnant of the ‘dermo-muscular tube’ of the ancestral form whose ventral side became greatly developed as an adaptation for creep­ing movement and the dorsal portion be­came degenerated.

In Mollusca, the foot originates at first as the ventral or ventro-lateral elevation of the ectodermal cells behind the mantle emerg­ing in Veliger and some other larval forms, later the mesodermal cells incorporate to give it a definite shape.