In this article we will discuss about the phylogeny and phylogenetic relationship of phylum Mollusca. Phylogeny of Mollusca: The phylogeny of Mollusca is a controversial issue. It was previously argued that Mollusca originated from annelids, generally assumption based on the evidence of fossilized monoplacophorans. But this theory was largely rejected because the body structure of Neopilina galatheae has revealed a [...]
In this article we will discuss about Pearl:- 1. Meaning of Pearl 2. Chemical Composition of Pearls 3. Shape, Size and Colour 4. Formation 5. Species Used in Pearl Culture 6. Distribution of Pearl Oysters in Indian Waters 7. Pearl Fishery in Japan and Other Countries. Meaning of Pearl: Pearl is a spherical or irregular mass formed by the [...]
In this article we will discuss about Achatina:- 1. Distribution of Achatina 2. Habit and Habitat of Achatina 3. External Structures 4. Coelom 5. Digestive System 6. Locomotion 7. Respiratory System 8. Circulatory System 9. Excretory System 10. Nervous System 11. Reproductive System 12. Development. Contents: Distribution of Achatina Habit and Habitat of Achatina External Structures of Achatina Coelom of [...]