nervous system until echinodermata

• Systematics


  The study of the diversity of organisms and their evolutionary relationships
• Introduction to zoological nomenclature

  • Animal-like protist
  • Phylum Porifera
  • Phylum Cnidaria
• Nomenclature


  The assigning of formal names to all or some of the tips and nodes of a hierarchical classification
• Biologists use the "BINOMIAL SYSTEM" for naming organisms
• Binomial nomenclature

  Scientific names of organisms consist of a genus name and a species name, written in italics with the genus name capitalised and the species name in lowercase
• Carolus Linnaeus published "Species plantarum" in 1753, establishing the binomial system of nomenclature
• Origins of scientific names


  • Descriptive
  • Scientist's names
  • Geographic places
  • Organizations
• Biologists desire a natural system of classification to infer the diversity of organisms
• Linnean hierarchy


  The taxonomic classification system developed by Carolus Linnaeus, including domains, kingdoms, phyla, classes, orders, families, genera, and species
• Animal-like protists


  Also known as protozoans, they are believed to be descendants of the forms of life that gave rise to multicellular organisms
• Phyla of animal-like protists

  • Amoebozoa
  • Euglenida
  • Kinetoplastida
  • Granuloreticulosa
  • Apicomplexa
  • Ciliata
• Euglena


  • Spindle-shaped with a pointed posterior and blunt anterior, has a pellicle, a long whip-like flagellum, contractile vacuoles, a nucleus with an endosome, chloroplasts, and paramylum bodies
• Trypanosoma


  • Spends most of its life in the blood and body fluids of vertebrate hosts, transmitted by tsetse flies, has a single flagellum originating from a posterior basal granule
• Amoeba


  • Has an outer ectoplasm and inner endoplasm, with a nucleus, contractile vacuole, and food vacuoles, forms temporary finger-like lobopodia for locomotion
• Foraminifera


  • Have shells or tests made of calcium carbonate with many chambers, extend slender pseudopodia through pores in the test
• Plasmodium


  • The causative agent of malaria, spends a large part of its life cycle within the host's red blood cells, transmitted by Anopheles mosquitoes, undergoes sexual reproduction by fusion of gametes
• Paramecium


  • Has a protective pellicle, an asymmetrical body with an oral groove, cilia covering the body, a large macronucleus and a smaller micronucleus, and contractile vacuoles for osmoregulation
• Vorticella


  • Has a bell-shaped body attached by a contractile stalk, cilia confined to the oral region, a bean-shaped macronucleus and a dot-like micronucleus, and food vacuoles
• Phylum Porifera


  Also known as sponges, they are sessile organisms that depend on water currents to bring in food and oxygen and carry away wastes, have a body mass of cells embedded in a gelatinous matrix and stiffened by spicules, and have no organs or tissues
• Classes of Porifera


  • Calcarea
  • Hexactinellida
  • Demospongiae
• Grantia


  • A calcareous sponge with an asconoid type of canal system, has a tube-like body with an osculum at the top and many ostia in the body wall, and contains triradiate spicules
• Euplectella


  • Also known as the Venus Flower Basket, has a long, curved, cylindrical body with a large spongocoel and a terminal osculum covered by a sieve plate
• Spongia


  • The common commercial bath sponge, has a complex network of spongin fibers and several oscula on the surface
• Carteriospongia


  • Has a broad leathery plate-like body with several oscula on the surface and is attached to the substrate by a root-like stalk
• Phylum Cnidaria


  Radially symmetrical organisms with two tissue layers (epidermis and gastrodermis) and a jelly-like mesoglea, have specialized stinging cells called cnidocytes or nematocysts for prey capture
• Classes of Cnidaria


  • Hydrozoa
  • Scyphozoa
  • Cubozoa
  • Anthozoa
• Hydra


  • A solitary polyp without a medusa stage, has a mouth surrounded by tentacles and a basal disk for attachment
• Obelia


  • Has both polyp and medusa stages in its life cycle, the colony consists of a main stem with side branches bearing feeding polyps (hydranths) and reproductive polyps (gonozooids)
• Aurelia


  • Also known as the moon jellyfish, has a semi-transparent, discoidal umbrella with a fringe of tentacles, a central manubrium with four oral arms
• Metridium


  • A sea anemone, has a flattened oral disk with circlets of tentacles around the central mouth, a short pharynx, and a gastrovascular cavity
• Elia


  • They contain young medusa buds stacked one on top of the other
  • A transparent, chitinous layer, the perisarc, covers the entire colony
• Aurelia


  • It has a semi-transparent umbrella, more discoidal and less cup-shaped than hydromedusae
  • It has short tentacles, from a fringe around the animal's umbrella margin. The tentacles are armed by nematocysts
  • The square mouth in the subumbrella opens at the end of the manubrium (a tube-like extension) which hangs down from the center of the subumbrella
  • The manubrium is drawn out to form four long, trough-like oral arms for prey capture and ingestion
• Metridium


  • The free end (oral end) is differentiated into a flattened oral disk that bears several short, hollow tentacles arranged in circlets around the central mouth
  • The slit-like mouth leads to a short pharynx and then into the gastrovascular cavity
  • It bears, at one or both ends, deep, ciliated grooves called siphonoglyphs that drive the water and its circulation into the gastrovascular cavity
  • At the opposite end of the column (aboral end) is the basal or pedal disk that attaches the animal to a solid substrate
• Acropora


  • The staghorn corals are plate-like colonies that are usually branching and bushy. The colony is made up of nonliving exoskeleton of calcium carbonate called corallum, secreted by the polyps that resemble sea anemones
  • Each individual coral polyp is found encased in a calcareous skeletal cup called corallite or calyx and are interconnected laterally
• Fungia


  • Mushroom corals are usually solitary and generally free-living except for juveniles
  • They are flat or dome-shaped (convex above and concave below), and circular or elongate in outline, with a central mouth
  • The skeleton of this very large polyp is limited to sclerosepta projecting from the basal plate
• Tubipora


  • Characterized by the lack of coenchyme, this alcyonarian produces a creeping may of stolons from which polyps arise singly
  • The tubes are connected at intervals by transverse calcareous plates or platforms
• Sarcophyton


  • The coenenchyme forms a rubber mass and the colony may have a massive mushroom shape
  • The polyps are embedded but restricted on the outer lobe of the fleshy coenenchyme, where they can extend and retract
  • Calcareous spicules are scattered and embedded in the coenenchyme
• Phyla

  • Platyhelminthes
  • Nematoda
  • Annelida
• The distinguishing feature of the phylum Platyhelminthes is worms with dorsoventrally flattened body
• Platyhelminthes lack a body cavity, hence called acoelomate