Polychaete Worms (pol-i-keet)

Classification Kingdom Animalia Phylum Annelida (segmented worms) Class Polychaeta 5000 species Nearly all marine

Structure Segmentation Organs Compartments Separated by septa (shallow partitions) Organs Systems Digestive Circulatory Nervous

Examples

Clam Worm Nereis Minimal specialization Typical polychaete body Repeated identical body segments Parapodia Paired paddle-shaped appendages Setae move parapodia and are connected to muscles

Nereis structure Head 2 segments Prostomium Sensory – Light, chemical, tactile Peristomium Mouth Contains the proboscis Folded structure that can extend from body with muscles Holds jaws that move with body’s fluid pressure

Clam Worm Diet Habitat Carnivores Omnivores Including scavengers Herbivores Habitat Rocky intertidal Burrow into mud and sand flats

Blood Worm Glycera Structure Possesses large proboscis 1/5 of body length Has 4 short antennae Each with a poison gland Sense changes in water pressure Can be as large as 20 in Makes nest of galleries (burrows)

Lug Worm Arenicola Deposit feeder Makes an L-shaped burrow Opens its mouth to pass sand through it’s digestive system Removes organic matter (nutrients) Creates a fecal mound (caste)