CLASSIFICATION
Kingdom Prokaryotae
Prokaryotic, unicellular organisms; heterotrophic by absorption, autotrophic by chemosynthesis or by photosynthesis; primarily asexual reproduction by binary fission but genetic exchange occurs by conjugation, transformation, transduction; motile forms move by flagella.
- Subkingdom Archaebacteria Bacteria that lack peptidoglycan walls. Methanogens, halophiles, thermoacidophiles.
- Subkingdom Eubacteria Bacteria having peptidoglycan walls:
- Gram-negative bacteria (thin layer of peptidoglycan)
- Phylum Chemoautotrophs Rod-shaped; derive energy
from oxidizing inorganic compounds. Nitrobacteria.
- Phylum Photoautotrophs Rod-shaped; derive energy from sunlight. Includes the anoxygenic photosynthesizers such as the purple nonsulfur bacterium Rhodospirillum and the oxygenic photosynthesizers such as the cyanobacteria, Anabena and Oscillatoria.
- Phylum Enterobacteria Rod-shaped, heterotrophic
bacteria. Salmonella, Escherichia coli, Vibrio cholerae. Phylum Myxobacteria Rod-shaped, form masses;
some are spore-bearing. Myxobacteria.
- Phylum Pseudomonads Rod-shaped, flagellated soil
bacteria. Pseudomonas.
- Phylum Rickettsias Obligate parasites of vertebrates and arthropods. Rickettsia.
- Phylum Spirochaetes Spiral-shaped, flagellated bacteria. Borrelia, Treponema.
- Phylum Cyanobacteria Photosynthetic bacteria; chlorophyll a and phycobilin. Anabena, Oscillatoria, Spirulina.
- Gram-positive bacteria (thick layer of peptidoglycan)
- Phylum Actinobacteria Spore-producing, filamentous bacteria. Actinomyces, Streptomyces, Mycobacterium.
Kingdom Protocrista
Eukaryotic, unicellular microorganisms and their immediate multicellular descendants; asexual and sexual reproduction; flagella and cilia with 9 + 2 microtubules. Nucleated algae, protozoa, slime molds, and water molds.
The Algae*
- Phylum Chlorophyta Mostly freshwater unicellular, colonial, or multicellular; chlorophylls a and b; starch accumulates within chloroplast. Cell wall; some with flagella. Green algae: Chlamydomonas, Spirogyra, Oedogomm, Ulva. 7,000 species.
- Phylum Phaeophyta Almost all marine, often multicellular; common along rocky coasts; chlorophylls a and c. Brown algae: Fucus, Laminaria, Nereocystis, Sargassum. 1,500 species.
- Phylum Chrysophyta Marine and freshwater, mostly unicellular; chlorophylls a and c. Cell wall in some contains silica. Diatoms and allies. I 1,000 species.
- Phylum Dinoflagella Mostly marine, unicellular; chlorophylls a and c. Cellulose plates for cell wall, two unequal flagella beat in grooves at right angles. Many are symbiotic and then known as zooxanthellae. Dinoflagellates. 1,000 species.
- Phylum Euglenophyta Mostly, freshwater, unicellular; often chlorophylls a and b. No cell wall; two flagella. Euglenoids: Euglena. 1,000 species.
- Phylum Rhodophyta Mostly marine, multicellular; chlorophyll a and phycobilin like the cyanobacteria. Red algae. 4,000 species.
The Protozoa*
- Phylum Sarcodina Freshwater and marine unicellular heterotrophs by ingestion; movement by pseudopods; no cell wall but marine forms may have shells; asexual reproduction. Amoebas and allies: Amoeba proteus, Entamoeba histolytica. 40,000 species.
- Phylum Ciliophora Freshwater unicellular heterotrophs by ingestion; movement by cilia; no cell wall but some have a flexible pellicle; asexual reproduction with complex sexual exchange through conjugation. Ciliates: Paramecium, Stentor, Vorticella. 8,000 species.
- Phylum Zoomastigophora Freshwater or parasitic unicellular heterotrophs by ingestion or absorption; movement by flagella. Asexual reproduction. Zooflagellates: Giardia, Trichomonas, Trypanosoma (African sleeping sickness).
- Phylum Sporozoa Unicellular het.erotrophs by absorption; nonmotile, spore-forming parasites of animals; complex life cycles. Sporozoa: Plasniodium (malaria), Pneumocysfis (pricurrionia), Toxigplasnia (toxoplasmosis). 3,600 species.
The Slime Molds and Water Molds*
- Phylum Gymnomycota Individual amoeboid cells or multinucleated mass; heterotrophic by ingestion; nonmotile spores with rigid cell walls and motile cells with flexible walls are produced. Slime molds. 560 species.
- Phylum Oomycota Filamentous mildews or molds with cellulose cell walls; heterotrophic by saprotrophism or parasitism; asexual reproduction by formation of zoospores; oogamy during sexual reproduction. Water molds. 580 species.
Kingdom Fungi
Multicellular eukaryotes; heterotrophic by absorption; lack flagella; nonmotile spores form during both asexual and sexual reproduction.
- Division Zygomycota Hyphae nonseptate; asexual reproduction common by sporangiospores; sexual reproduction involves thick-walled zygospore. Zygospore fungi: soil and dung molds, black bread molds (Rhizopus). 600 species.
- Division Ascomycota Hyphae septate; asexual reproduction common by conidiospores; sexual reproduction involves dikaryotic hyphae with formation of ascospores in asci. Sac fungi: many small wooddecaying fungi, yeasts (Saccharomyces), molds (Neurospora), morels, cup fungi, truffles; plant parasites: powdery mildews, ergots. 30,000 species.
- Division Basidiomycota Hyphae septate; asexual reproduction by conidiospores; sexual reproduction common by long-lasting dikaryotic mycelium with fort-nation of basidiospores on basidia. Club fungi: mushrooms, stinkhoms, puffballs, bracket and shelf fungi, coral fungi; plant parasites: rusts, smuts. 16,000 species.
- Division Deuteromycota Hyphae septate; asexual reproduction common by conidiospores; sexual reproductive structures are not known. Imperfect fungi:
athlete's foot, ringworm, candidiasis. 25,000 species.
Kingdom Plantae
Multicellular, primarily terrestrial eukaryotes with welldeveloped tissues; autotrophic by photosynthesis; alternation of generations life cycle. Like green algae, plants contain chlorophylls a and b, carotenoids; store starch in chloroplasts; cell wall contains cellulose.
- Division Hepatophyta. Strap-shaped (some leafy, some thallose), that creep along the substrate; dominant garnetophyte and dependent sporophyte; mostly moist
and shaded habitats. Liverworts. 10,000 species.
- Division Bryophyta Stemlike, leaflike, and rootlike
structures; dominant gametophyte and dependent
sporophyte; mostly moist and shaded habitats. Mosses.
12,000 species.
- Division Anthocerotophyta nallose plants with green
gametophytes; photosynthetic sporophytes at the upper
surface of gametophyte; dominant gametophyte and
dependent sporophyte; mostly moist and shaded habitats. Hornworts. 100 species.
The Vascular Plants
- Division Psilotophyta Rhizome with erect branched stems; no roots or leaves; tenninal sporangia borne on stems; tropical and subtropical habitats. Whisk ferns.
Several species.
- Division Lycopodophyta In Lycopodium, rhizome with upright branches and roots; scalelike leaves (microphylls) cover stems and branches; sporangia mostly borne in terminal cones; mostly tropical and subtropical but also temperate to Arctic and dry habitats. Club mosses, spike mosses, quillworts. 1,000 species.
- Division Equisetophyta In Equisetum, horizontal underground rhizome jointed stems; whorled branches and scalelike leaves; sporangia borne in terminal cones; moist habitats. Horsetails. 15 species.
- Division Pteridophyta Well-developed leaves (megaphylls) called fronds; sporangia on sporophylls; moist, shaded habitats common; sometimes dry areas. Ferns. 12,000 species.
The Seed Plants
Gymnosperms
- Division Pinophyta Woody tree with thick trunk; needlelike or scalelike evergreen leaves (some shrubby); reproductive organs in pollen and seed cones; widespread distribution. Conifers: pines, firs, yews, redwoods, spruces. 550 species.
- Division Cycadophyta nick woody stem; large leaves resembling palm fronds; massive male and female cones; mostly tropical and subtropical. Cycads. 100 species.
- Division Ginkgophyta Woody tree with long side branches; fan-shaped deciduous leaves; microsporangia in cones, naked ovules on stalks; gardens and parks. Maidenhair tree. One living species.
- Division Gnetophyta In Gnetum, trees and climbing vines with large leathery leaves; moist tropical habitat. In Ephedra, a profusely branched shrub with small, scalelike leaves; desert habitat. In Welwitschia, massive woody, disk-shaped stem with straplike leaves; desert habitat.
Gnetophytes. 70 species.
The Angiosperms
- Division Magnoliophyta Trees, shrubs, herbs; most with broad leaves; herbs are perennials or annuals; reproductive organs in flower; pollen often carried by insects; double fertilization; seeds enclosed by fruits; widespread distribution; some aquatic. Flowering plants.
- Class Liliopsida (monocot) Flower parts in threes or multiples of threes; parallel-veined leaves; one cotyledon. Grasses, lilies, pineapple. 65,000 species.
- Class Magnoliopsida (dicot) Flower parts in fours, fives, or multiples of these; net-veined leaves; two cotyledons. Most flowering herbs, shrubs, trees. 170,000 species.
Kingdom Animalia
Multicellular organisms with well-developed tissues; usually motile; heterotrophic by ingestion, generally in a digestive cavity; diplontic life cycle.
- Phylum Porifera Multicellular bodies perforated by many pores that admit water which exits through the only opening; internal skeleton of spicules; digestion within collar cells (choanocytes); regeneration possible. Mostly marine sponges. 5,000 species.
- Phylum Cnidaria Two-layered radially symmetrical body; gastrovascular cavity has only one opening; characterized by presence of stinging cells (cnidocytes); regeneration possible; all aquatic and most marine. Hydras, jellyfishes. 9,000 species.
- Class Cubozoa Medusa form square with toxic sting. Sea wasps, box jellyfish.
- Class Anthozoa Polyp forms with no medusae. Sea anemones, corals.
- Class Hydrozoa Polyp form dominant, often colonial, frequently with an alternation of generations. Hydra,Obelia.
- Class Monogenea Parasitic, with hooks. Anchor worms.
- Class Scyphozoa Medusa form dominant. Aurelia.
- Phylum Ctenophora Free-swimming, often almost spherical animals; translucent, sometimes bioluminescent; plates of cilia and a thick layer of mesoglea; radially symmetrical with two very long, specialized tentacles. Comb jellies, sea walnuts. 90 species.
- Phylum Platyheiminthes Three-layered bilaterally symmetrical body; gastrovascular cavity has only one opening; excretion by means of flame cells; complex hermaphroditic reproductive systems; regeneration possible.
Flatworms. 13,000 species.
- Class Turbellaria Ciliated, carnivorous with eyespots.
Planaria.
- Class Trematoda Parasitic with oral and ventral suckers; digestive cavity. Flukes.
- Class Cestoda Parasitic with scolex having hooks and suckers and proglottids; no digestive cavity. Tapeworms.
- Phylum Nemertea Usually marine worms with proboscis apparatus; acoelomate; a complete digestive system. Ribbon worms. 650 species.
- Phylum Nematoda Nonsegmented worms; pseudocoelom and a tube-within-a-tube body plan; free living and parasitic. Roundworms: Ascaris. 12,000 species.
- Phylum Rotifera Microscopic, pseudocoelomate wormlike or
spherical animals with a corona (circle of cilia) on the
head, the beating of which resembles a revolving
wheel. Rotifers. 2,000 species.
The Protostomes
Schizocoelomates; the first embryonic
opening is associated with the mouth; cleavage is spiral and determinate.
- Phylum Mollusca Body divided into foot, visceral mass, and mantle; usually also radula and shell; reduced coelom. Mollusks. 110,000 species.
- Class Polyplacophora Body flattened dorsoventrally; shell consisting of eight dorsal plates; grazing marine herbivores. Chitons.
- Class Bivalvia Body enclosed by a shell consisting of -Ives; no head or radula; wedge-shaped foot; marine and freshwater sessile filter feeders. Clams, scallops, oysters, mussels.
- Class Cephalopoda Tentacles about head;'shell may be reduced or absent; head in line with elongated visceral mass, closed circulatory system; welldeveloped nervous system with cephalization; marine active predators. Squids, chambered nautilus, octopus.
- Class Gastropoda Shell is coiled if present; body symmetry distorted by torsion; head with tentacles; marine, freshwater, and terrestrial grazing herbivores. Snails, slugs, nudibranchs.
- Phylum Annelida Segmented worms with a long, cylindrical, soft body; protostome coelomates with internal septa; specialized digestive tract; definite central nervous system with brain and ventral solid nerve cord; closed circulatory system. Annelids. 12,000 species.
- Class Polychaeta Marine with good cephalization; bundles of setae on parapodia. Clam worms (Nereis), tube worms.
- Class Oligoehaeta Fewer setae with no parapodia; no distinct head in terrestrial forms. Earthworms.
- Class Hirudinea External parasites or scavengers, or with anterior and posterior suckers; parapodia and setae absent. Leeches.
Phylum - Arthropoda (Animals With An Exoskeleton)
Chitinous exoskeleton with jointed appendages specialized in structure and function; well-developed central nervous system with brain and ventral paired nerve cord; reduced coelom; hemocoel. Arthropods. Over 30 million species.
Subphylum Trilobitomorpha (Trilobita) Three-lobed body with distinct head, thorax, and abdomen; serially repeated biramous appendages; extinct.
Subphylurn Chelicerata Chelicerae, pedipalps, and four pairs of walking legs attached to a cephalothorax; no antennae, mandibles, or maxillae. Spiders, scorpions, horseshoe crabs.
Class - Merostomata - Horseshoe Crabs
Class - Arachnida - Arachnids
Arachnid Orders
- Scorpionida (Scorpiones) - Scorpions
- Pseudoscorpionida - Pseudoscorpions
- Solfugae - Sun Spiders
- Uropygi - Whip Scorpions (Vinegaroons)
- Amblypygi - Tailless Whipscorpions (Whipspiders)
- Araneae - Spiders
- Ricinulei - Ricinuleids
- Opiliones - Daddy Longlegs (Harvestmen)
- Acarina (Acari) - Mites and Ticks
Class- Pycnogonida - Sea Spiders
Subphylum Crustacea Compound eyes and five pairs of walking appendages; antennae and antennules, mandibles and maxillae on head; biramous appendages on thorax and abdomen. Lobsters, crayfish, shrimps, crabs, many others.
Class - Branchiopoda - Fairy Shrimp, Water Fleas, Etc.
Class - Copepoda - Fish Lice Etc.
Class - Ostracoda - Ostracods
Class - Cirripedia - Barnacles
Class - Malacostraca - Lobsters, Crayfish, Crabs, Isopods, and Shrimps
Subphylum Uniramia (Atelocerata) Uniramous appendages; one pair of antennae, one pair of mandibles, and one or two pairs of maxillae; terrestrial with tracheae. Millipedes, centipedes, insects.
Class - Onychophora - Velvet Worms (Peripatus) (Of uncertain status, may be a link between Annelid Worms and Arthropods)
Class - Diplopoda - Millipedes
Class - Chilopoda - Centipedes
Class- Insecta (Hexopoda)
Insect Orders
- Protura- Proturans
- Thysanura - Bristletails and Silverfish
- Collembola - Spring Tails
- Ephemeroptera - Mayflies
- Odonata - Dragonflies and Damselflies
- Orthoptera - Grasshoppers, Crickets, and Katydids
- Dictyoptera - Praying Mantids (Mantodea) and Roaches (Blattaria)
- Phasmatodea (Phasmida) - Walkingsticks
- Isoptera - Termites
- Plecoptera - Stoneflies
- Dermaptera - Earwigs
- Embioptera - Webspinners
- Psocoptera - Booklice and Barklice
- Zoraptera - Zorapterans
- Mallophaga - Chewing Lice
- Anoplura - Sucking Lice
- Thysanoptera - Thrips
- Hemiptera - True Bugs
- Homoptera - Cicadas, Hoppers, Whiteflies, Aphids, and Scale Insects
- Neuroptera - Dobsonflies, Fishflies, Alderflies, Lacewings, and Antlions
- Coleoptera - Beetles
- Strepsiptera - Twisted-Winged Parasites
- Mecoptera - Scorpionflies
- Trichoptera - Caddisflies
- Lepidoptera - Moths, Skippers, and Butterflies
- Diptera - (Two-Winged Flies) Houseflies, Horseflies, Mosquitos, and Gnats
- Hymenoptera - Sawflies, Ichneumons, Chalcids, Ants, Wasps, and Bees
- Siphonaptera - Fleas
The Deuterostomes
Enterocoelomates; the second embryonic opening is associated with mouth; cleavage is radial and indeterminate.
Phylum - Echinodermata (Echinoderms)
- Radial symmetry; endoskeleton of spine-bearing plates; water vascular system with tube feet. Echinoderms. 6,000 species.
- Class Crinoidea Filter feeders with feathery arms. Sea lilies, feather stars. 600 species.
- Class Asteroidea Five arms project from central disk; movement by tube feet. Sea stars. 1,500 species.
- Class Ophiuroidea Slender, long, often spiny, highly flexible arms from central disk. Brittle stars. 2,000 species.
- Class Echinoidea No distinct arms; spines used for locomotion, defense, burrowing. Sea urchins, sand dollars. 950 species.
- Class Holothuroidea Long, leathery body with tentacles about mouth. Sea cucumbers. 1,500 species.
- Phylum Hemichordata Marine; wormlike body divided into proboscis, collar, trunk; pharyngeal gill slits and dorsal hollow nerve cord in proboscis. Hemichordates: acorn worms. 90 species.
Phylum - Chordata (Chordates)
- Phylum Chordata Pharyngeal pouches; dorsal hollow nerve cord; notochord; post-anal tail. Chordates. 45,000 species.
- Subphylum Urochordata Larva free swimming with three chordate characteristics; adults sessile filter feeders with plentiful gill slits. Tunicates. 1,250 species.
- Subphylum Cephalochordata Marine fishlike animals with three chordate characteristics as adults. Lancelets. 23 species.
The Vertebrates
Subphylum Vertebrata Notochord replaced by vertebrae that protect the nerve cord; skull that protects the brain; segmented with jointed appendages. Vertebrates. 43,700 species.
- Superclass Agnatha Marine and freshwater fishes; lack jaws and paired appendages; cartilaginous plates added to notochordal skeleton; notochord. Lampreys, hagfishes. 63 species.
- Superclass Gnathostomata Hinged jaws; paired appendages. Jawed fishes, tetrapods.
- Chordate Classes
- Class Chondrichthyes Marine cartilaginous fishes; lack operculum and swim bladder; tail fin usually asymmetrical. Sharks, skates, rays. 850 species.
- Class Osteichthyes Marine and freshwater bony fishes; operculum; swim bladder or lungs; tail fin usually symmetrical. Lungfishes, lobe-finned fishes, rayfinned fishes (herring, salmon, sturgeon, eels, sea horse). 20,000 species.
- Class Amphibia Tetrapod with nonamniote egg; nonscaly skin; metamorphosis; three-chambered heart; ectothermic. Urodeles (salamanders, newts), anurans (frogs, toads). 3,900 species.
- Class Reptilia Tetrapod with amniotic egg; scaly skin; ectothermic. Squamata (snakes, lizards), chelonians (turtles, tortoises); crocodilians (crocodiles and alligators). 6,000 species.
- Class Aves Tetrapod with feathers; bipedal with wings; double circulation; endothermic. Sparrows, penguins, ostriches. 9,000 species.
- Avian Orders
- Coraciiformes - Kingfishers
- Apodiformes - Hummingbirds
- Strigiformes - Owls
- Columbiformes - Pigeons
- Falconiformes - Eagles, Hawks, and Falcons
- Anseriformes - Ducks
- Gaviiformes - Loons
- Charadriiformes - Gulls
- Pelecaniformes - Pelicans
- Ciconiiformes - Herons
- Podicipediformes - Grebes
- Struthioniformes - Ostrich
- Galliformes - Chickens, Turkeys, Pheasants, and Quail
- Piciformes - Toucans
- Passeriformes (Perching Birds) - Sparrows, Larks, Thrush, Robins, and Mockingbirds
- Sphenisciformes - Penguins
- Phoenicopteriformes - Flamingos
- Psittaciformes - Parrots
- Class Mammalia Tetrapods with hair, mammary glands; double circulation; endothermic; teeth differentiated. Monotremes (spiny anteater, duckbill platypus), marsupials (opossum, kangaroo), placental mammals (whales, rodents, dogs, cats, elephants, horses, bats, humans). 4,500 species.
- Mammal Orders
- Monotremata - Platypus and Spiny Anteater
- Marsupialia (Pouched Mammals) - Opossums, Wombats, and kangeroos
- Insectivora - Shrews, Tenrecs, and Moles
- Sirenia - Manatees
- Perissodactyla - Rhinoceros
- Tubulidentata - Aardvark
- Hyracoidea - Hyrax
- Cetacea - Whales and porpoises
- Carnivora - Lions, Tiger, Bears, and Dogs, etc.
- Rodentia - Squirrels, Chipmunks, Rats, and Mice, Etc.
- Primates - Lemurs, Monkeys, Gorillas, Chimpanzees, and Man, Etc.
- Chiroptera - Bats and Flying Foxes
- Lagomorpha - Rabbits
- Pholidota - Pangolins (Scaley Anteaters)
- Dermoptera - Flying Lemurs
- Artiodactyla - Sheep
- Pinnipedia - Walrus and Seals
- Edentata - Anteaters
- Proboscidea - Elephant