This document summarizes the circulation, support, growth, movement, neural control, and sensory organs of various invertebrate phyla. It describes that mollusks have open or closed circulatory systems, annelids have closed circulatory systems with aortic arches, and arthropods and echinoderms have a variety of circulatory approaches. Support and movement is enabled through muscles, appendages, shells, and water vascular systems. Neural control systems include nerve cords, ganglia, sensory hairs and various eye structures.

1. Advanced Invertebrates Circulation Support, Growth & Movement Nervous Systems (cont’d)

2. Circulation mollusks bivalves and gastropods – open w/ hemolymph & heart cephalopods – closed w/ heart annelids – closed w/ aortic arches arthropods crustaceans – open chelicerates – open uniramians – open w/ heart & aorta echinoderms – cellular diffusion

3. Support, Growth & Movement mollusks Gastropods have 1 shell exhibit torsion move w/ wavelike contractions of foot Bivalves have 2 shells move with “hatchet foot” extruded from body

4. Support, Growth & Movement mollusks Cephalopods jet propulsion stabilize with fins sometimes can crawl very malleable body

5. Support, Growth & Movement annelida longitudinal muscles circular muscles parapodia – stumpy leg-like appendages setae – bristle like hairs

6. Support, Growth & Movement arthropods molt to grow larger – shed exoskeleton unprotected until new exoskeleton hardens many muscles jointed appendages allow full range of motion

7. Support, Growth & Movement echinodermata metamorphosis from bilaterally symmetrical larvae called bipinnaria to radially symmetrical adult movement with a water vascular system

8. Neural Control & Sensory Organs annelids chain of ganglia ventral nerve cord connects ganglia in each segment setae

9. Neural Control & Sensory Organs arthropods crustaceans paired ganglia pair of branched antenna & pair of antennules, sensory hairs compound eyes on stalks chelicerates brain simple eyes: usually three or more uniramians brain & ventral nerve cord paired ganglia in each segment antenna & sensory hairs simple & compound eyes tympanum: sound sensing

10. Neural Control & Sensory Organs echinodermata nerve ring radial nerves