MOLLUSCA:
The word Mollusca derived from the Latin word which means “soft body”. Molluscas(Molluscs for short): are bilaterally symmetrical, have bodies consisting of more than one layer of cells, tissues, and organs, have bodies without cavities, have advanced nervous systems, have circulatory systems with both a heart and aorta, and have a pair of kidneys. Molluscs are the second most diverse phylum only below Arthropoda, with 110,000 species known which are mostly marine organisms. Molluscs occupy a large range of habitats from the arctic seas to high mountains and even deserts. The size of Molluscs range from microscopic species to the largest of all Molluscs, the giant squid (which weighs up to 270 kg and up to 65 meters long). Molluscs are ancient organisms that are believed to have evolved from a worm-like species during the Precambrium Period about 650 million years ago; because most Molluscs grow and form with a shell of some sort, the fossil record of Molluscs is good. Mollusc shells have been used as one of the earliest forms of money. Three classes of the phlyum Mollusca, in terms of the skeletal system are Bivalvia, Cephalopoda, and Scaphopoda.
The word Mollusca derived from the Latin word which means “soft body”. Molluscas(Molluscs for short): are bilaterally symmetrical, have bodies consisting of more than one layer of cells, tissues, and organs, have bodies without cavities, have advanced nervous systems, have circulatory systems with both a heart and aorta, and have a pair of kidneys. Molluscs are the second most diverse phylum only below Arthropoda, with 110,000 species known which are mostly marine organisms. Molluscs occupy a large range of habitats from the arctic seas to high mountains and even deserts. The size of Molluscs range from microscopic species to the largest of all Molluscs, the giant squid (which weighs up to 270 kg and up to 65 meters long). Molluscs are ancient organisms that are believed to have evolved from a worm-like species during the Precambrium Period about 650 million years ago; because most Molluscs grow and form with a shell of some sort, the fossil record of Molluscs is good. Mollusc shells have been used as one of the earliest forms of money. Three classes of the phlyum Mollusca, in terms of the skeletal system are Bivalvia, Cephalopoda, and Scaphopoda.