ZO O LO GY L EC TU R E N OTES
CHAPTER FOCUS
Faunal Diversity
ORGANISM PROFILES, SYSTEMATICS & LIFE CYCLES
, 1. PARAMECIUM CAUDATUM
Systematic Position
KINGDOM Protista
PHYLUM Protozoa
CLASS Ciliata
GENUS Paramecium
SPECIES caudatum
Habit & Habitat
• Unicellular, eukaryotic organism.
• Found in freshwater environments i.e., rivers, ponds, and lakes.
• Inhabits stagnant water, moist damp places, and also occurs on decaying organic matter.
Structure & Morphology
• Shape: Resembles the sole of a shoe, hence it is commonly called the slipper animalcule.
• Size: Characteristically ranges from 0.06 mm to 0.3 mm in length.
• Orientation: Anterior end is semicircular and blunt; Posterior end is pointed; Ventral surface is flat; Dorsal
surface is concave.
External & Internal Structural Components
• Pellicle: Thin, transparent, and elastic membrane covering the body.
◦ Cilia: Hair-like structures arising from the pellicle used for locomotion.
◦ Trichocysts: Specialized organelles used for offense and defense against enemies. Composed of a
distinct cap and shaft.
• Oral Groove: A large depression located on the anterior end of the ventral side.
• Protoplasm: Differentiated into an outer Ectoplasm (thin, transparent, and non-granular) and an inner
Endoplasm (thick and granular).
• Dimorphic Nucleus: Possesses two distinct types of nuclei:
◦ Macronucleus: Large, bean-shaped nucleus that controls all vegetative/metabolic activities.
Page 2
CHAPTER FOCUS
Faunal Diversity
ORGANISM PROFILES, SYSTEMATICS & LIFE CYCLES
, 1. PARAMECIUM CAUDATUM
Systematic Position
KINGDOM Protista
PHYLUM Protozoa
CLASS Ciliata
GENUS Paramecium
SPECIES caudatum
Habit & Habitat
• Unicellular, eukaryotic organism.
• Found in freshwater environments i.e., rivers, ponds, and lakes.
• Inhabits stagnant water, moist damp places, and also occurs on decaying organic matter.
Structure & Morphology
• Shape: Resembles the sole of a shoe, hence it is commonly called the slipper animalcule.
• Size: Characteristically ranges from 0.06 mm to 0.3 mm in length.
• Orientation: Anterior end is semicircular and blunt; Posterior end is pointed; Ventral surface is flat; Dorsal
surface is concave.
External & Internal Structural Components
• Pellicle: Thin, transparent, and elastic membrane covering the body.
◦ Cilia: Hair-like structures arising from the pellicle used for locomotion.
◦ Trichocysts: Specialized organelles used for offense and defense against enemies. Composed of a
distinct cap and shaft.
• Oral Groove: A large depression located on the anterior end of the ventral side.
• Protoplasm: Differentiated into an outer Ectoplasm (thin, transparent, and non-granular) and an inner
Endoplasm (thick and granular).
• Dimorphic Nucleus: Possesses two distinct types of nuclei:
◦ Macronucleus: Large, bean-shaped nucleus that controls all vegetative/metabolic activities.
Page 2
