1. Phylum
    2. 1. Classification of Animals
    2. Protozoa
    3. Porifera
    4. Coelenterata
    5. Platyhelminthes
    6. Nemathelminthes
    7. Annelida
    8. Earthworm
    9. Arthropoda
    10. Cockroach
    11. Mosquito
    12. Honey bee and Silk moth
    13. Mollusca
    14. Echinodermata
    15. Hemichordata
    16. Chordata
    17. Pisces
    18. Amphibia
    19. Frog
    20. Reptile
    21. Aves
    22. Mammalia
    23. Rabbit bone
  2. Animal Behaviour and Adaptation
    3. 24. Animal behaviour
    25. Animal adaptation
    26. Migration
  3. Developmental Biology
    4. 27. Development of Animals
    28. Development of Frog
  4. Human Biology
    5. 29. Tissues
    30. Sense organs
    31. Digestive system
    32. Circulatory system
    33. Respiratory system
    34. Nervous system
    35. Endocrine system
    36. Reproductive system
    37. Excretory system
    38. Skeletal system
    39. Basic concept of Immunology
    40. Human diseases
  5. Evolutionary Biology
    6. 41. Origin of Life
    42. Organic Evolution
    43. Theories of Evolution
    44. Evolution of Human beings
    45. Horse Evolution
Animal Behaviour and Adaptation
25. Animal adaptation
▢ Aquatic Adaptation (Water 💦 Inhabitant):
❖ Primary Aquatic Adaptation (Gill Breathers):
◉ Adaptive Features:
◈ Body Contour:
■ Body Shape:
  1. Streamlined
  2. Laterally compressed
■ Head: Subconical
■ Neck: Absent
◈ Locomotion:
■ Primary: Lateral undulation of flexible body
■ Secondary: Fins
◈ Swim Bladder/Air Bladder:
  1. Hydrostatic in function
  2. Also functions in breathing
◈ Gills: Primary respiratory organs
◈ Lateral Line Sense Organs: Detects changes caused by mechanical disturbance in surrounding water
◈ Scales: Forms protective covering/Exoskeleton of the body
◈ Nictitating Membrane/3rd Eyelid: Eye 👁‍🗨 protection and for making vision clear
◉ Examples:
    ❖ Secondary Aquatic Adaptation (Lung Breathers):
    ◉ Adaptive Features:
    ◈ Body Contour:
    ■ Body Shape:
    ● Head: Sub-conical
    ● Neck: Shortens
    ● Tail: Enlarges
    ■ External Ears: Reduced in amphibious mammals and totally lost in fully aquatic forms
    ■ Lungs: Large in size to store large amount of oxygen
    ◈ Locomotive Mechanism:
    ■ Oar Propulsion:
    ● Limbs: Equally sized limbs like turtle
    ● Propulsion: Propulsive power generated as that of oar (by displacing water)
    ■ Tail Propulsion:
    ● Limbs: Hind limbs tend to disappear (e.g., cetacea, sirenians)
    ● Propulsion: Propulsive power generated from strong tail
    ■ Note: Propulsive power is stronger in oar propulsion than in tail propulsion
    ◈ Limbs:
    1. Webbed feet
    2. Limbs developed into flipper or paddles
      3. ● Hyperdactyly & Hyperphalangy: Increase in no. of digits and phalangeal bones helps in limb enlargement for displacing more water
    ◈ Integument:
    ■ Skin: Naked (reduction of hair, skin glands)
    ■ Blubber: Subcutaneous fat layer developed to compensate hair loss
    ◉ Examples:
      ▢ Aerial/Volant Adaptation (Flying ✈):
      ❖ Adaptive Features:
      ◉ Body Shape: Boat or Spindle shaped
      ◉ Neck:
      ◈ Long and modified:
      ◈ Beak:
      ■ Description: Modification of jawbones in birds
      ■ Function: Preening (spreading oil secreted by Uropygial glands)
      ◉ Tail: Short
      ◉ Body Covering: Feathers
      ◉ Flight Muscles:
      ◈ Pectoralis Major: Depresses/Lowers wings
      ◈ Pectoralis Minor: Elevates/Raises wings
      ◉ Limbs:
      ◈ Forelimbs: Modified into wings
      ◈ Hindlimbs:
      1. Strong and modified for automatic perching
      2. Slightly anterior for balance
      ◉ Endoskeleton:
      ◉ Respiratory System: Inelastic lungs supplemented by airsacs
      ◉ Nervous System: Highly developed cerebellum
      ◉ Reproductive System: Single functional ovary (left side) for weight reduction
      ❖ Examples:
      ◉ Flight Types:
      ◈ Gliding/Passive Flight:
      ■ Description: No locomotive power ⛮ applied from body
      ■ Examples:
      1. Exocoetus (Flying fish)
      2. Rhacophorus (Flying frog)
      3. Draco (Flying lizard)
      ◈ True/Active Flight:
      ■ Description: Locomotive power applied from body
      ■ Examples:
      1. Birds
      2. Bat
      ▢ Desert 🏜 Adaptation:
      ❖ Adaptive Features:
      ◉ Water Conservation:
      1. Tough, thick skin to avoid perspiration
      2. Reduced sweat glands
      3. Highly concentrated urine
      4. Water cells in rumen (e.g., Camel)
      ◉ Senses: Well-developed sight, hearing, smell
      ◉ Protection: Eyes, ears, nostrils protected from sand
      ◉ Eyelids: Highly enlarged
      ◉ Special Adaptation: Desert lizard 🦎 has hygroscopic skin absorbing atmospheric water
      ❖ Examples:
        ▢ Fossorial/Burrowing Adaptation:
        ❖ Adaptive Features:
        ◉ Body Contour:
        ◈ Body Shape:
        1. Cylindrical (Snakes, Ichthyphis)
        2. Fusiform/Spindle-shaped (Mole)
        ◈ Head: Tapers into snout
        ◉ Limbs: Short forelimbs with powerful claws for digging
        ❖ Examples:
          ▢ Arboreal/Scansorial Adaptation (Climbing):
          ❖ Adaptive Features:
          ◉ Body Contour:
          ◈ Shape: Long, narrow elongated body
          ◈ Vertebrae:
          1. Dorsolumbar elongation
          2. Increased count (19 to 25-27)
          ◉ Limb Girdles:
          1. Strongly built
          2. Curved ribs
          3. Well-developed clavicle & scapula
          4. Broad, flat ilium for visceral support
          ◉ Limbs:
          ◈ General: Usually plantigrade
          ◈ Types:
          ■ Branch Runners: Equal fore/hind limbs
          ■ Suspending Forms: Elongated humerus in forelimbs
          ◉ Feet:
          1. Prehensile (Grasping) with opposable digits (Syndactyly common)
          2. Non-Prehensile
          ◉ Tail:
          1. Prehensile
          2. Long for balancing
          ❖ Examples:
          ◉ Marsupials:
          1. Kangaroo
          2. Koala
          ▢ Cursorial/Running Adaptation:
          ❖ Adaptive Features:
          ◉ Body Shape:
          ◈ Body: Spindle-shaped/Streamlined
          ◈ Neck: Shortened
          ◉ Limbs:
          ◈ Forelimbs: Less developed
          ◈ Hindlimbs: Stout, muscular, longer
          ◈ Bone Reduction:
          1. Fibula
          2. Ulna
          ◉ Foot Posture:
          ❖ Examples: