phylum mollusca notes
-Blood without haemoglobin and circulatory system open. Things to remember. -Body - Head, Thorax and Abdomen(three parts). Phylum Mollusca Characteristics. Each mollusk has a muscular organ called a foot that is used for gripping or creeping over surfaces. 1.100). Some secrete a hard shell. Generally, these animals live in water. The proportion of undescribed species is very high. Phylum 2. Start studying Intro to Mollusca Notes and Class Gastropoda notes. They possess osphradia to test the chemical nature of water. -Excretion by malpighian tubules. The statocysts maintain body equilibrium. The group Mollusca, established by Cuvier (1798), comprises of almost 1,00,000 species and is the second largest animal phylum (Fig. Phylum Mollusca is a very diverse (85,000 species ) group of mostly marine species, with a dramatic variety of form. Phylum Arthropoda( Jointed Legs) – -Largest phylum. GENERAL CHARACTERISTICS BODY CHARACTERS : Soft Unsegmented Triploblastic No jointed appendages SYMMETRY : Bilaterally symmetrical SHELL : Externally mantle secretes a hard , brittle , calcareous shell . They also possess ink glands for protection. Many organisms belonging to this phylum have a calciferous shell. 2 nd largest animal phylum after Arthropoda. Key Points on Mollusca. There is a between Mollusca and Echinodermata in terms of morphological, physiological and behavioural characteristics. Members of the phylum Mollusca are soft-bodied animals, such as the snail, clam, squid, oyster, and octopus. 3. Phylum Mollusca and Phylum Echinodermata belong to the Kingdom Animalia. It protects the soft body . Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Soft-bodied invertebrate covered with protective mantle that may or may not form a hard, calcium carbonate shell; Includes chitons, snails, slugs, clams, oysters, squid, octopus, & nautilus; Second largest animal phylum; Have a muscular foot for movement which is modified into tentacles for squid & octopus PHYLUM MOLLUSCA (SOFT BODY) I. CHARACTERISTICS A. ; Unio contains a digestive gland called Green gland, which is comparable to liver of vertebrates. However, both molluscs and echinoderms are triploblastic, and they possess a complete digestive system. -Respiration by gills, book lungs and trachea. 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. It is primitive with segmented body. Octopus has 8 arms and contains no shell. Phylum Mollusca 1. Phylum Mollusca is the second largest phylum. Contains snails, slugs, octopus, squid, and the "shell fish" (clams, oysters,limpets, and scallops); second largest phylum (greater than 100,000 species) B. This phylum can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda. Neopilina is considered as connecting link between Annelida and Mollusca. Phylum Mollusca – -Soft body animals. Learn vocabulary, terms, and more with flashcards, games, and other study tools. -Bilateral symmetry, Triploblastic, segmented coelomate. Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda.The members are known as molluscs or mollusks (/ ˈ m ɒ l ə s k /).Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. A few molluscs such as Unio possess green glands which mimic the liver in vertebrates. ; Statocysts- for maintaining equilibrium of the body. Phylum Mollusca.