Lecture—6 October 2003

Acanthocephalans

Cuticle

Round in cross section

Spiny head

Lack digestive track

Parasites in birds, mammals

Gastrotrichs

Small, microscopic, infaunal

They live in the spaces between the grains that make up the substrate in marine environments (interstitial fauna)

Arthropoda

Monophylic or

Polyphylic

Characteristics

Paired Jointed appendages

Exoskeleton

They are segmented, typically segments are associated with body regions (tagmata)

Shed exoskeleton

Mouthparts

Mandibles or chelicera

Appendages

Metanephric system (green gland) malphigian tubules

Ammonia, uric acid

Respiratory

Gills, book lungs