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Animal Taxonomy Kingdom: Animalia Systematic Position Kingdom: Animalia Subkingdom: Eumetazoa Division: Triploblastica Sbdivision: coelomates Phylum: Mollusca 1-Class: Gastropoda Example: snails Phylum: Mollusca • • • • • Mollusca includes snails and slugs, octopuses and squids. Most mollusks are marine, though some inhabit fresh water, and some snails and slugs live on land. Mollusks are soft-bodied animals, but most are protected by a hard shell of calcium carbonate. All mollusks have a muscular foot for locomotion, a visceral mass with most of the internal organs, and a mantle. Most mollusks have separate sexes, with gonads located in the visceral mass, and some are hermaphrodites. 1-Class: Gastropoda Example: snails • • Most Gastropoda are marine, but there are also many freshwater species. The anus and mantle cavity are above the head in adults. • Most gastropods are protected by a spiraled shell. • Other species have lost their shells entirely and may have chemical defenses against predators. • Many gastropods have distinct heads with eyes at the tips of tentacles. • They move by their foot. • Some species are predators. Kingdom: Animalia Systematic Position Kingdom: Animalia Subkingdom: Eumetazoa Division: Triploblastica Sbdivision: coelomates Phylum: Mollusca 2- Class: Cephalopoda Example: Octopus 2- Class: Cephalopoda Example: Octopus • Cephalopods use rapid movements toward their prey which they capture with several long tentacles. • A mantle covers the visceral mass, but the shell is reduced and internal in squids missing in many octopuses. • • • • The foot of a cephalopod (“head foot”) has been modified into the muscular siphon and parts of the tentacles Most octopuses live on the seafloor. Cephalopods have an active, predaceous lifestyle. They have a welldeveloped nervous system with a complex brain and welldeveloped sense organs. Kingdom: Animalia Systematic Position Kingdom: Animalia Subkingdom: Eumetazoa Division: Triploblastica Sbdivision: coelomates Phylum: Annelida Class: Oligochaeta Genus: Allolobophora (Earthworm) Species: caliginosa Allolobophora caliginosa • • • • All annelids (“little rings”) have segmented bodies. Annelids live in the sea, most freshwater habitats, and damp soil. The coelom of the earthworm, a typical annelid, is partitioned by septa, but the digestive tract, longitudinal blood vessels, and nerve cords penetrate the septa and run the animal’s length. Most annelids, including earthworms, burrow in sand and silt. • • The digestive system consists of a pharynxء, an esophagus, crop, gizzard and intestine The closed circulatory system carries blood with oxygen-carrying hemoglobin through dorsal and ventral vessels connected by segmental vessels. • In each segment is a pair of excretory tubes, metanephridia, that remove wastes from the blood and coelomic fluid. • Earthworms are cross-fertilizing hermaphrodites. • Some earthworms can also reproduce asexually by fragmentation followed by regeneration. Kingdom: Animalia Systematic Position Kingdom: Animalia Subkingdom: Eumetazoa Division: Triploblastica Sbdivision: pseudocoelomates Phylum: Nematoda (Roundworms) Class: Rhalditea Order: Ascariida Family: Ascariidae Genus: Ascaris Species: lumbricoides Ascaris lumbricoides Ascaris • Roundworms are pseudocoelomates covered by tough cuticles • Roundworms are found in most aquatic habitats, wet soil, moist tissues of plants, and the body fluids and tissues of animals. Some species parasitize animals. They range in length from less than 1 mm to more than a meter. The body of Nematode is covered with a tough exoskeleton, the cuticle. They have a complete digestive tract. Nematodes usually engage in sexual reproduction. • • • • • The Summary