Many organisms belonging to this phylum have a calciferous shell. The body is cylindrical or vase shaped with bristly outer surface. Estimates of the number of species alive today range from 50,000 to 130,000. Contains snails, slugs, octopus, squid, and the "shell fish" (clams, oysters,limpets, and scallops); second largest phylum (greater than 100,000 species) B. Body divided into head, muscular foot and visceral hump. Phylum Annelida is divided into four main classes, primarly on the basis of setae, parapodia, metameres and other morphological features. chitons. True coelomates (schizocoelomates). 1. PDF | On Jan 1, 2016, Richard C. Brusca and others published Phylum Mollusca | Find, read and cite all the research you need on ResearchGate Most mollusks are herbivores, carnivores or filter feeders Protection Run away, hide in shell, release ink, secrete poisonous or distasteful chemicals, sting, camouflage . Classification Kingdom- Animalia Phylum- Mollusca 4 classes: 3. Polyplacophora. Kidney Function. They are terrestrial or aquatic (both marine and freshwater). Download Phylum - Mollusca MCQ Question Answer PDF « Animal Kingdom Organ. Most of the shells found on the beaches of the modem world belong to mollusks and mollusks are probably the most abundant invertebrate animals in modern oceans. Geothermal. Members of this phylum include snails, octopuses, squids, oysters etc. Phylum Mollusca means “soft body” 100,000 species of mollusks often called “shellfish” basic body plan-have soft body divided into 4 major parts 1. head-contains mouth & sensory organs 2. foot-used for movement 3. visceral mass-contains internal organs 4. mantle-thin layer of tissue that covers visceral mass & protects organs; also, secretes calcium carbonate for shell 249 1 University of KwaZulu-Natal, School of Life Sciences, Pietermaritzburg, South Africa 2 Southern Underwater Research Group, Kommetjie, Cape Town 3 South African Environmental Observation Network, Egagasini Node, Cape … Mollusca Notes 1. Most of these animals have a closed digestive system with only one opening, and a true coelom. Phylum Mollusca. These 64 slides will provide your students with a solid lesson on the animals found in the Phylum Mollusca and their characteristics. Animal Kingdom Classification System Class 11 Notes Download In PDF ☞ Class 12 Solved Question paper 2020 ☞ Class 10 Solved Question paper 2020. Lamarck coined the term Molluscus. Biology notes for O level. Inside the shell, a delicate layer called mantle envelops the whole visceral mass. The bodies are generally very soft and are covered by the hard exoskeleton.They can be found in terrestrial regions as well as in the depths of the seas.You will be amazed to know that the size of the molluscans can range from 20 metres to one millimetre, with a few microscopic animals too. They are usually white, long and thin. Phylum Mollusca . The diversity of the phylum is shown by at least eight known classes (cover). major features of mollusks • Learn the external and internal anatomy of the clam and squid • Understand the major advantages and limitations of the exoskeletons of mollusks in relation to the hydrostatic skeletons of worms and the endoskeletons of vertebrates, which you will examine later in the semester Section 21.5 Figure 21.15 Key features Mollusks Are Soft and Unsegmented. You are on page 1 of 35. ADVERTISEMENTS: 2. Search inside document . General Characteristics of Phylum Mollusca: 1. 249-320. Lamellidense, commonly known as mussels, belong to phylum-Mollusca, class — Bivalvia, and subclass — Palaeoheterodonta. Many, however, occur in fresh water and some even in damp soil. Phylum Mollusca - From mollus meaning “soft” 2. Classes in Phylum Mollusca.