Question

Please help me with this. Thanks

	Porifera	Cnidaria	Platyhelminthes	Mollusca	Annelida	Nematoda	Arthropoda
# of tissue layers
Symmetry type
Body Cavity
sac or tube/alimentary canal?
Protostome or Deuterostome? (or neither)
What type of environment(s) do they live in?
What/How do they eat?
Adaptations for digestion
Adaptations for respiration (how do they breathe?)
How do they circulate materials? Adaptations for circulation
How do they sense their environment?
Reproduction/life cycle details
Major groups (classes or subphyla)
Other key traits/notes

Answer 1

•   Phylum – Porifera (Gr., porus = pore; ferre = to bear)
   Salient features :-
-   Porifera means organisms with holes.
-   They are multicellular, radially symmetrical or asymmetrical organisms exhibiting cellular level of organization (tissue system not developed).
-   Most animals of this group are sedentary, plant – like, aquatic (fresh water or marine), and remain attached to the bottom of the sea.
-   Body is made up of two germ layers, i.e., they are diploblastic.
-   The skeleton of sponges is formed of needle – like structures known as spicules. Spicules are made up of calcium carbonate or silica or sponging fibres.
-   Whole body is perforated, bearing small pores called ostia. Ostia open into a single cavity called spongocoel, which opens to the exterior through a large opening called osculum. A regular flow of water is maintained through ostia, spongocoel and osculum. This system of water movement is called canal system, which exist in all sponges.
Water from outside  Ostia  Spongocoel  Osculum  Outside.
Examples :- Sycon (Scypha)
       Bath sponge (Euspongia)
       Boring sponge (Cliona)
       Freshwater sponge (Spongilla)
       Glass – rope sponge (Hyalonema)
       Horse sponge (Hippospongia)
       Finger sponge (Halichondria)
       Venus flower basket (Euplectella)
       Neptune’s goblet sponge (Poteria)

•   Phylum – Coelenterata (Cnidaria) (Gr., Koilos = hollow; enteron = gut)
   Salient features :-
-   Coelenterates are primitive, multicellular, aquatic animals. Their cells are organized into tissues.
-   They are diploblastic, have two layers of germ cells – ectoderm and endoderm.
-   They have a radially symmetrical body. Mouth is surrounded by a ring of tentacles.
-   Body contains a large cavity called coelenterons or gastrovascular cavity. Coelenterons has a single opening for ingestion and egestion.
-   Body contains a loose network of nerve cells.
-   Body bears special cells called nematocysts for defence, offence and to capture food.
-   Coelenterates exist in two forms – an asexual polyp form and a sexual medusoid form. In a few coelenterates, these two forms alternate with each other during life history, a phenomenon called alternation of generation.
-   Some of them live solitary life, eg., Hydra while some live in colonies, e.g., corals.
Examples :-   Freshwater polyp (Hydra)
       Organ pipe coral (Tubipora)
       Portuguese man of war (Physalia)
       Jellyfish (Aurelia)
       Sea pansy (Renilla)
       Sea anemone (Metridium)
       Red coral (Corallium)
       Sea pen (Pennatula)
       Mushroom coral (Fungia)
       Sea fan (Gorgonia)
       Soft coral (Alcyonium)

•   Phylum – Platyhelminthes (Gr., platys = flat; helminthes = worm)
   Salient features :-
-   They are bilaterally symmetrical, elongated, dorsoventrally flattened animals, commonly called flatworms.
-   Triploblastic, i.e., body consists of three germ layers, namely, ectoderm, mesoderm and endoderm.
-   Body is soft, leaf – like (liver fluke) or ribbon – like (tapeworm). They are acoelomate (no body cavity present).
-   Respiration and excretion by general body surface. Circulatory system is absent.
-   Excretory organs are in the form of flame cells.
-   Digestive system when present, bears a single opening, the mouth.
-   Mostly parasites (e.g. Tapeworm) but some are free – living forms (e.g. Planaria). Parasites bear spines, hooks or suckers.
-   Reproductive organs are highly developed.
-   Most of them are hermaphrodites, i.e., male and female reproductive organs are present in the same individual. Fertilization is internal.
Examples :-   Liverfluke (Fasciola hepatica)
       Blood fluke (Schistosoma)
       Pork tapeworm (Taenia solium)
       Beef tapeworm (Taenia saginata)
       Echinococcus
       Planaria

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