Sponges and Cnidarians
Objectives:• Explain how sponges feed and reproduce.• List classes, identify representatives, and list
characteristics.
Phylum Porifera "pore bearers"
– Sponges• Salt – fresh water• Vaselike or
encrusting
Phylum Porifera "pore bearers"
Characteristics– Skeleton
• spongin (elastic fibers) • spicules (hard siliceous) • calcareous structures
– Assymetrical body form– body contains small openings
(pores)– Feeding: filter water through
pores
Sponge Reproduction– Asexually
• buds break off and grow into separate sponges
– sexually using male and female gametes
• http://www.pbs.org/kcet/shapeoflife/episodes/origins_explo1.html
Phylum Cnidaria "able to sting"
Types of Cnidarians– Class Hydrozoa
(Portuguese Man-of-War)
– Class Scyphozoa (jellyfish)
– Class Anthozoa (sea anemones, corals)
Phylum Cnidaria "able to sting"
Characteristics– able to sting– occur in one of two
body forms: polyp (sea anemone, coral) or medusa (jellyfish)
– have radial symmetry – similar body parts are arranged and repeated around a central axis
Feeding– carnivores (animals that prey
on other animals)– tentacles are arranged
around a central mouth– nematocysts (stinging cells)
to stun and capture prey which bring food to mouth into gut
Cnidarian Reproduction
• Sexual• Asexual - budding
• http://www.youtube.com/watch?v=BpKKGB-ivQo
• http://www.youtube.com/watch?v=RYVHK2vM1_Y