Animal Phyla:A Summary
Danilo V. Rogayan Jr.Faculty, College of Education, Arts and Sciences
Ramon Magsaysay Technological University
Phylum Platyhelminthes 2
Phylum Platyhelminthes
• The phylum consists of four classes• Turbellaria (flatworm)
• Trematoda (fluke)
• Cestoda (tapeworm)• Monogenian
Triclad Flatworm
Summary
• The first groups of worms that we will discuss are the flatworms. As their common names suggest, flatworms are flattened dorso-ventrally and soft-bodied. Some intestinal tapeworms may grow up to 100 feet (30 meters). All flat worms belong to Phylum Platyhelminthes. Turbellaria (e.g Planaria), Cestoda (e.g tapeworm) and Trematoda. (e.gfluke).
Phylum Nematoda
• Nematodes (Gr. nematos, thread) or roundworms
• About 16,000 species have been described
• Triploblastic, bilateral, vermiform (resembling a worm in shape; long and slender), unsegmented
• Body round in cross section and covered by a layered cuticle; molting usually accompanies growth in juveniles
Phylum Nematoda
• Complete digestive tract; mouth usually surrounded by lips bearing sense organs
• Most with unique excretory system comprised of one or two renette cells or a set of collecting tubules
• Body wall has only longitudinal muscles
Phylum Annelida
• Members of the phylum Annelida are the segmented worms.
• Metamerism has important influences on virtually every aspect of annelid structure and function.
Phylum Annelida
• Members of the class Polychaeta are annelids that have adapted to a variety of marine habitats. Some live in or on marine substrates; others live in burrows or are freeswimming.
• Parapodia and numerous, long setae characterize the polychaetes.
Phylum Mollusca
• Molluscs are protostomes. Relationships to other protostomes are distant and evolutionary pathways are speculative.
• Molluscs have a coelom, as well as a head-foot, visceral mass, mantle, and mantle cavity
• Most also have a radula
Phylum Mollusca
• Members of the class Gastropoda are the snails and slugs. They include the only terrestrial molluscs. Torsion and shell coiling modify their bodies.
• Clams, oysters, mussels, and scallops are members of the class Bivalvia. They are all aquatic filter feeders and often burrow in soft substrates or attach to hard substrates.
Phylum Mollusca
• The class Cephalopoda includes the octopuses, squids, cuttlefish, and nautili. They are the most complex of all invertebrates and are adapted for predatory lifestyles.
• Other molluscs include members of the classes Scaphopoda (tooth shells), Monoplacophora, Aplacophora(solenogasters), and Polyplacophora(chitons). Members of these classes are all marine.
Phylum Arthropoda
• The arthropods are by far the most successful phylum of animals, both in diversity of distribution and in numbers of species and individuals.
• They have adapted successfully to life in water, on land and in the air.
Phylum Arthropoda
• About 80% of all known animal species belong to the Arthropoda - about 800,000 species have been described, and recent estimates put the total number of species in the phylum at about 6 million.
Phylum Arthropoda
• Arthropods are found in a greater variety of habitats than any other animal group; on top of mountains, at great depths in the ocean and in the icy wilderness of Antarctica.
• They can survive great extremes of temperature, toxicity, acidity and salinity.
Phylum Echinodermata
• Although many classes of echinoderms are extinct, living echinoderms are divided into six classes: (1) Asteroidea, sea stars; (2) Ophiuroidea, brittle stars and basket stars; (3) Echinoidea, sea urchins and sand dollars; (4) Holothuroidea, sea cucumbers; (5) Crinoidea, sea lilies and feather stars; and (6) Concentricycloidea, sea daisies.