PHYLUM ANNELIDA
General Characteristics
• came from the Latin word "annellus" meaning little ring
• formerly known as vermes
• has an anterior head with sense organs
• has a posterior end
• may have a distinct head
• elongate and flattened body
Distinct Characteristics
• no single feature distinguishes from other invertebrate phyla, but they have a
distinctive combination of features
• segmented body with cuticle covering
• closed circulatory system
• divided externally by shallow ring-like constrictions (annuli) and internally by
septa; in some species the septa are incomplete or absent
Mode of Life (Habitat)
• terrestrial
• freshwater
• marine
Mode of Life (Feeding Mechanism)
• parasites
• predators
• grazers
• detritivores
• filter feeders
,Mode of Life (Reproduction)
• sexual: through sex cells in the body cavity
• asexual: excretion of sperm and egg in the sea
Mode of Life
Mode of Life
,Anatomy and Structure (Soft Parts)
Anatomy and Structure
NERVOUS SYSTEM
• cerebral ganglia
• mid-ventral nerve cord
CIRCULATORY SYSTEM
• closed
• around 2 to 5 principal blood vessels
• peristaltic pulsations of the dorsal vessel
• contractions of five pairs of hearts in earthworms
, DIGESTIVE SYSTEM
• mouth
• esophagus
• gizzard
• intestine
General Characteristics
• came from the Latin word "annellus" meaning little ring
• formerly known as vermes
• has an anterior head with sense organs
• has a posterior end
• may have a distinct head
• elongate and flattened body
Distinct Characteristics
• no single feature distinguishes from other invertebrate phyla, but they have a
distinctive combination of features
• segmented body with cuticle covering
• closed circulatory system
• divided externally by shallow ring-like constrictions (annuli) and internally by
septa; in some species the septa are incomplete or absent
Mode of Life (Habitat)
• terrestrial
• freshwater
• marine
Mode of Life (Feeding Mechanism)
• parasites
• predators
• grazers
• detritivores
• filter feeders
,Mode of Life (Reproduction)
• sexual: through sex cells in the body cavity
• asexual: excretion of sperm and egg in the sea
Mode of Life
Mode of Life
,Anatomy and Structure (Soft Parts)
Anatomy and Structure
NERVOUS SYSTEM
• cerebral ganglia
• mid-ventral nerve cord
CIRCULATORY SYSTEM
• closed
• around 2 to 5 principal blood vessels
• peristaltic pulsations of the dorsal vessel
• contractions of five pairs of hearts in earthworms
, DIGESTIVE SYSTEM
• mouth
• esophagus
• gizzard
• intestine
