ANIMAL KINGDOM

Phylum Porifera

• Members called sponges;

• mostly marine, some freshwater;

• mostly asymmetrical;

• primitive multicellular animals;

• cellular level of organisation;

• water transport (canal) system present;

• water enters through ostia, passes into spongocoel and exits through osculum;

• canal system helps in food gathering, respiration and waste removal;

• choanocytes (collar cells) line spongocoel and canals;

• digestion intracellular;

• skeleton made of spicules or spongin fibres;

• hermaphrodite;

• asexual reproduction by fragmentation;

• sexual reproduction by gametes;

• fertilisation internal;

• development indirect with larval stage;

• Examples: Sycon (Scypha), Spongilla, Euspongia

Phylum Coelenterata (Cnidaria)

Aquatic, mostly marine; sessile or free-swimming; radial symmetry; tissue level of organisation; diploblastic; cnidoblasts (cnidocytes) with nematocysts present for defence, anchorage and prey capture; gastrovascular cavity with single opening (mouth) on hypostome; digestion extracellular and intracellular; skeleton of calcium carbonate in corals; body forms polyp (sessile, cylindrical)- Hydra, Adamsia and medusa (free-swimming, umbrella-shaped)- Aurelia, Jelly fish; alternation of generations (metagenesis) in some- obelia; Examples: Physalia, Adamsia, Pennatula, Gorgonia, Meandrina, Aurelia

Phylum Ctenophora

Comb jellies or sea walnuts; exclusively marine; radial symmetry; diploblastic; tissue level of organisation; eight rows of ciliated comb plates for locomotion; digestion extracellular and intracellular; bioluminescence present; hermaphrodite; reproduction only sexual; fertilisation external; development indirect; Examples: Pleurobrachia, Ctenoplana

Phylum Platyhelminthes

Flatworms with dorso-ventrally flattened body; mostly endoparasitic; bilateral symmetry; triploblastic; acoelomate; organ level of organisation; hooks and suckers in parasitic forms; nutrients absorbed through body surface; flame cells for osmoregulation and excretion; hermaphrodite; fertilisation internal; development indirect with many larval stages; high regeneration in some; Examples: Taenia, Fasciola

Phylum Aschelminthes (Nematoda)

Roundworms with circular cross-section; free-living or parasitic; organ-system level of organisation; bilateral symmetry; triploblastic; pseudocoelomate; complete alimentary canal with muscular pharynx; excretory tube opens by excretory pore; sexes separate (dioecious); females usually longer; fertilisation internal; development direct or indirect; Examples: Ascaris, Wuchereria, Ancylostoma

Phylum Annelida

• Aquatic (marine and freshwater) or terrestrial;

• free-living or parasitic;

• organ-system level;

• bilateral symmetry;

• triploblastic;

• true coelom;

• metameric segmentation;

• circular and longitudinal muscles which helps in locomotion;

• Nereis possesses lateral appendages-parapodia (help in swimming);

• closed circulatory system;

• nephridia for excretion and osmoregulation;

• nervous system with paired ganglia connected by lateral nerves to double ventral nerve cord;

• monoecious (earthworms, leaches) or dioecious (nereis);

• sexual reproduction;

• Examples: Nereis, Pheretima (earthworms), Hirudinaria (blood sucking leach)

Phylum Arthropoda

• Largest phylum- includes insects;

• over two thirds of all named species on earth are arthropods;

• organ-system level;

• bilateral symmetry;

• triploblastic;

• segmented;

• coelomate;

• body covered with chitinous exoskeleton;

• body divided into head, thorax and abdomen;

• jointed appendages;

• respiration by gills, book gills, book lungs or trachea;

• open circulatory system;

• sensory organs like antenna, eyes(compound and simple), statocysts or balancing are present;

• Malpighian tubules for excretion;

• dioecious;

• fertilisation usually internal;

• mostly oviparous;

• development direct or indirect;

• Examples: Apis (honey bee), Bombyx (silkworm), Laccifer (lac insect), Vectors- Anopheles, Culex and Aedes (Mosquitoes)

  Gregarious pest- Locusta (locust), Living fossil- Limulus (king crab)

Phylum Mollusca

• Second largest phylum;

• terrestrial or aquatic (Marine or freshwater);

• organ-system level;

• bilateral symmetry;

• triploblastic;

• coelomate;

• soft unsegmented body;

• body divided into head, muscular foot and visceral hump;

• calcareous shell present;

• soft and spongy layer of skin forms mantle over the visceral hump. space between mantle and hump is called mantle cavity in which feather like gills (respiratory and excretory functions) are present;

• anterior head region consists sensory tentacles

• mouth contains a file like rasping organ called radula;

• usually dioecious;

• oviparous;

• development indirect;

• Examples: Pila (Apple snail), Pinctada (Pearl oyster), Sepia (Cuttlefish), Loligo (squid), Octopus (Devil fish), Aplysia (Sea hare), Dentalium (Tusk shell), Chaetopleura (Chiton)

Phylum Echinodermata

• Endoskeleton of calcareous ossicles hence named echinodermata;

• spiny-bodies animals;

• exclusively marine;

• organ-system level organisation;

• adults radially symmetrical, larvae bilaterally symmetrical;

• triploblastic;

• coelomate;

• complete digestive system;

• mouth on lower ventral side and anus on upper dorsal side;

• distinct feature- water vascular system for locomotion, capture and transport of food and respiration;

• excretory system absent;

• dioecious (sexes are separate);

• sexual reproduction;

• fertilisation external;

• development indirect with free swimming larva;

• Examples: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber), Ophiura (Brittle star)

Phylum Hemichordata

• Have a rudimentary structure in the collar region called stomochord, a structure similar to notochord

• worm-like marine animals;

• organ-system level;

• bilateral symmetry;

• triploblastic;

• coelomate;

• body is cylindrical and divided into anterior proboscis, collar and trunk;

• open circulatory system;

• respiration by gills;

• proboscis gland for excretion;

• dioecious (sexes are separate);

• fertilisation external;

• development indirect;

• Examples: Balanoglossus, Saccoglossus

Subphylum Urochordata

Marine chordates; notochord present only in larval tail; adult loses notochord; Examples: Ascidia, Salpa, Doliolum

Subphylum Cephalochordata

Marine chordates; notochord extends from head to tail; persists throughout life; Examples: Branchiostoma (Amphioxus)

Class Cyclostomata

Jawless vertebrates; ectoparasites on fishes; elongated body; 6–15 pairs of gill slits; circular sucking mouth; no scales or paired fins; cartilaginous skeleton; closed circulation; marine but migrate to freshwater for spawning; die after spawning; Examples: Petromyzon, Myxine

Class Chondrichthyes

Marine fishes; cartilaginous endoskeleton; streamlined body; ventral mouth; placoid scales; gill slits without operculum; persistent notochord; two-chambered heart; air bladder absent; poikilothermous; internal fertilisation; many viviparous; Examples: Scoliodon, Pristis, Carcharodon, Trygon

Class Osteichthyes

Bony fishes; marine and freshwater; streamlined body; terminal mouth; gills covered by operculum; cycloid or ctenoid scales; air bladder present; two-chambered heart; cold-blooded; fertilisation usually external; mostly oviparous; development direct; Examples: Exocoetus, Hippocampus, Labeo, Catla, Clarias, Betta, Pterophyllum

Class Amphibia

Live both on land and water; moist scaleless skin; two pairs of limbs; eyes with eyelids; tympanum present; cloaca present; respiration by gills, lungs and skin; three-chambered heart; cold-blooded; sexes separate; fertilisation external; oviparous; development indirect; Examples: Bufo, Rana, Hyla, Salamandra, Ichthyophis

Class Reptilia

Mostly terrestrial; dry cornified skin with scales or scutes; tympanum present; limbs may be present or absent; heart usually three-chambered, four in crocodile; poikilothermous; internal fertilisation; oviparous; development direct; Examples: Chelone, Testudo, Calotes, Chameleon, Crocodilus, Alligator, Hemidactylus, Naja, Bangarus, Vipera

Class Aves

Body covered with feathers; beak present; forelimbs modified into wings; hindlimbs adapted for walking or perching; skin dry with oil gland; pneumatic bones; crop and gizzard present; four-chambered heart; warm-blooded; lungs with air sacs; internal fertilisation; oviparous; development direct; Examples: Corvus, Columba, Psittacula, Struthio, Pavo, Aptenodytes, Neophron

Class Mammalia

Mammary glands present; hair on skin; external ears (pinnae); two pairs of limbs with various adaptations; heterodont teeth; four-chambered heart; warm-blooded; lungs for respiration; sexes separate; internal fertilisation; mostly viviparous; development direct; Examples: Ornithorhynchus, Macropus, Pteropus, Camelus, Macaca, Rattus, Canis, Felis, Elephas, Equus, Delphinus, Balaenoptera, Panthera tigris, Panthera leo