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