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PROTOZOA GENERAL CHARACTERS & CLASSIFICATION. Dr. P. RAVI SEKHAR LECTURER IN ZOOLOGY GOVT. COLLEGE FOR MEN (AUTONOMOUS) KADAPA. PROTOZOA GENERAL CHARACTERS & CLASSIFICATION.
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PROTOZOA GENERAL CHARACTERS & CLASSIFICATION Dr. P. RAVI SEKHAR LECTURER IN ZOOLOGY GOVT. COLLEGE FOR MEN (AUTONOMOUS) KADAPA
PROTOZOA GENERAL CHARACTERS & CLASSIFICATION The animals kingdom is often distinguished into two major categories, is based on a singular character, the notochord. Animals without notochord are called Non –Chordates. Animals possessing notochord are called Chordates.
Major and minor Phyla • Invertebrates are divided into major and minor phyla. The concept of major and minor phyla depends upon two factors. • Number of species and individuals in the phyla • Participation of Phyla in ecological communities • On the basis of these two factors Major phyla : 9 Minor phyla : 21
Introduction • Protozoans are microscopic and acellular animalcules, without tissue and organs. • First discovered by Antony Von Leeuwenhoek in1671. • Van Siebold(1845) identified protozoans as single cellular organisms. • Dobell named them as acellular or Non-cellular animals. • Goldfuss named these organism as Protozoans (G., protos=first; zoan=animal). • About 50,000 species have been identified and named. This phylum includes free and parasitic forms and cosmopolitan in distribution.
PROTOZOA GENERAL CHARACTERS
PROTOZOA - GENERAL CHARACTERS • Protozoans are first formed animals • Small microscopic animalcules • Originated in Precambian period of Paleozoic era. • Shape: Some of them are spherical, oval, ball shaped, while some other are shapeless (or) irregular.
PROTOZOA - GENERAL CHARACTERS • Habitat: Distributed all over the world, free living symbionts, commensals and parasites. • Lives in water, soil, air, on animals and inside the animals. • Symmetry: Radial or spherical, bilateral symmetry and Asymmetrical,
PROTOZOA - GENERAL CHARACTERS • All are unicellular, body madeup of a single cell • Single cell is capable of carrying out all the metabolic activities, which characterized the animal body. • Body is naked or bounded by a pellicle, some have shellor exoskeleton madeup of CaCo3orsilica. • Size: 0.002 mm to 16mm in size. • A fossil, Nummulite is large and measured 19cm.
PROTOZOA - GENERAL CHARACTERS • Nucleus: Usually only one nucleus, eilophores have two nuclei (dimorphic) One nucleus is large and called macronucleus it carry all vegetative metabolic activities and the other is small and called micronucleus which is exclusively for reproduction. Locomotion: Locomotor organelles are finger – like pseudopodia or wip like flagella or hair like cilia or absent.
Nutrition:holozoic (animal like), holophytic (plant like), saprozoic or parasitic. Digestion occurs intracellular inside of food vacuoles. • Respiration: No special respiratory organs, Respiration is carried by general body surface through diffusion. • Excretion:Through diffusion or through contractile vacuoles which serves mainly for osmoregulation.
PROTOZOA - GENERAL CHARACTERS • Reproduction:Asexually and Sexually • Asexual reproduction by binary fusion, multiple fusion or budding. • Sexual reproduction by conjugation or by fusion of gametes (syngamy). • Life history often completed with alternation of asexual and sexual phases. • Encystment is a common protective phase, commonly occurs to resist the unfavorable conditions of food.
PROTOZOA - CLASSIFICATION • There are different opinions on the classification of protozoa. • According to B.M. Honigberg (1964), Carlis (1967)the phylum protozoa is classified in to four subplyla: • Sub phylum : Sarcomastigophora • Sub phylum : Sporozoa • Sub phylum : Cnidospora • Sub phylum : Ciliophora
PHYLUM - PROTOZOA Sporozoa Cnidospora Ciliophora Sarcomastigophora Mastigophora Sarcodina Haplosporia Opalinata Teleosporia Taxoplasmia Phyrophasmida Actinopoda Phyto Mastigophora Zoo Mastigophora Rhizopoda Mixosporidia Microsporidia Ciliata Sub Phylum Super class Class Class Class Class Class
PROTOZOA - CLASSIFICATION • SUB PHYLUM - I. SARCOMASTIGOPHORA • Locomotory organs are flagella , pseudopodia or any one of them. • One kind of Nuclei • Body is covered by protective Pellicle. • This sub phylum is divided into three super classes: 1) Mastigophora, 2) Opalinata, 3) Sarcodina
Super class 1: Mastigophora (Flagellata): • The locomotary organs are flagella • Nutrition is autotropic or heterotropic or both • The body is surrounded with firm pellicle • They are divided into two classes: 1. Phytomastigophora, 2. Zoo mastigophora
Class 1: Phytomastigophora (= Phytoflagellata) • Chlorophil, chromatophores are present. • Nutrition mainly holophytic • Organisms are with one or two flagella. • Reserve food material is starch or paramylon • Orders: Chrysomonalida, Cryptomonalida, Euglenida, Volvocida, Chloromonadida and Dinoflagellida. • Eg: Chrysamoeba, Chilomonas, Clathodiccidella, Discoaster, Euglena, Clamydomonas,Volvox, Coelomonas, Noctiluca, Ceratium
PROTOZOA - CLASSIFICATION • Class 2: Zoomastigophora (= Zooflagellata) • Chlorophil or chromatophoresabasent • Nutrition is holozoic or saprozoicmostly parasitic • The reserve food is glycogen • orders : Rhizomastigida, kinetoplastida, Choanoflagellida, Diplomonadida, Hypermastigida and Trichomonadida • Eg: Mastogamoeba, Dimorpha, Leishmania, Trypanosoma, proterospongia, Giardia, Lophomonas, Trychonympha, Trichomonas etc
Super class 2: Opalinata : • Entire body covered by cilia like flagella • The Nuclei are two to many and are monomorphic • They lead parasitic life mainly on amphibians • Reproduction is by binary fission or by syngamy • This includes only one order i.e. Opalinida • Eg: Opalina, Jellirilla Opalina
PROTOZOA - CLASSIFICATION • Super class 3: Sarcodina • locomotary organs are Pseudopodia and help in food capturing • Mostly free living some are parasitic • Nutrition is holozoic or saprozoic • Food vacuoles, contractile vacuoles are present. Marine forms lack contractile vacuoles. • Encystmenttakes place in unfavorable conditions • They are divided into three classes: Rhizopoda, Actinopoda, Pyroplasmida
Class 1: Rhizopoda: • Pseudopodia are lobopodia, filopodia or reticulopodia. • In general body is naked without pellicle, in some cases body is enclosed in chambered shell. • Protoplasm is divided into outer ectoplasm and inner endoplasm. • Eg: Amoeba, Entamoeba, Arcella Difflugia, Globigerina Euglypha, Elphidium, Laberinthula etc. Globigerina Elphidium
PROTOZOA - CLASSIFICATION Class 2: Actinopoda: • Pseudopodia are delicate and form of axopodia and reticulopodia • These are round and floats on water • Body may be naked or enclosed with chitin or silica shell • Eg: Thallaciocola, Actinophyns (sun animalcule), Acanthometra, Clathrulina. Pseudospora etc. Actinophyns ( Thallaciocola,
Class 3: Phyrophasmida: • Blood parasites in vertebrate blood. • Cilia and flagella are absent • Gliding locomotion • Eg: Thilaria, Babesia
PROTOZOA - CLASSIFICATION • SUB PHYLUM - II. SPOROZOA: • Locomotory organelles are absent • Exclusively endoparasites • Body is covered by protective pellicle • Asexual reproduction - multiple fission. • Sexual reproduction - fusion of micro and macro gametes. • It is divided in to three classes : Teleosporia, Texoplasmia, Haplosporia
Class 1: Teleosporia: • Monogenetic or digenetic parasites • Produce spores without polar capsule of filament • Locomotary organelles are absent - gliding locomotion • Ex: Celenadium, Monocystis, Gregarina, Neina, Ophiocystis, Eimeria, Plasmodium etc. • Class 2 : Texoplasmia: • They lead parasitic life on Humans, Birds and Reptiles • Only asexual reproduction - binary fission Ex: Sarcocystis, Taxoplasma
PROTOZOA - CLASSIFICATION SUB PHYLUM – III . CNIDOSPORA: • All are parasites • Spores with polar filaments, spores formation occur throughout the life • Asexual reproduction is by binary fusion, • Sexual reproduction is by iso or anisogamets. • There are two classes in this subphylum: Myxosporidea, Microsporidea • Class 1 : Myxosporidea: • Spores are large, developed from several nuclei • Valvular membrane encloses the gamets. • It includes orders: Mixosporida, Actinomixida, Helicosporida Ex: Mixidium, Leptotheca, Triactinomixon, Helicosporidium
Class 2 : Microsporidea: • Spores are very small developed from one nucleus. • The spores may be with or without polar capsule. • They live as parasites ininsectsandfishes. • It includes only one order: Microsporidia • Ex: Cadospora, Nosema
PROTOZOA - CLASSIFICATION SUB PHYLUM - IV. CILIOPHORA: • Locomotor and feeding organelles are cilia • Body covered with hard pellicle and posses cilia all over the body • All these organisms included in the class Ciliata • Micro nucleus and macronucleus are present • In ciliates one or more contractile vacuoles are present • Reproduction is by sexual and asexual methods • Ex: Praramoecium, Balantidium, Vertecella, Didinium, Ephelota, Nectotherus, Podophrya etc.