Phylum Cnidaria [ni’ der ee uh]

Characteristics of Cnidarians Radial Symmetry

Characteristics of Cnidarians Sessile

Characteristics of Cnidarians . . .and Motile

Characteristics of Cnidarians Tissues- cells specialized for different purposes.

Characteristics of Cnidarians Gastrovascular cavity- digestive cavity with one opening.

Characteristics of Cnidarians Nervous System Nerve Net- No brain

Characteristics of Cnidarians Things Cnidarians don’t have: Brain- or “central nervous system” Circulatory System- No heart, no blood Excretory Organs Respiratory- no gills or lungs Skeletal System

Characteristics of Cnidarians Cnidocytes- Stinging cells Poisonous Use Pressure Automatic

Characteristics of Cnidarians

Cnidarian Reproduction

Cnidarian Reproduction 2 body forms in lifecycle Medusa- motile; produce eggs or sperm. Polyp- sessile; reproduces asexually to form new medusae Both forms are diploid

Cnidarian Reproduction Cnidarian Larvae = Planula

Cnidarian Reproduction Polyp budding Asexual

Cnidarian Reproduction Polyps

Cnidarian Diversity Anthozoa- Corals and Anenomes

Cnidarian Diversity Scyphozoa- True Jellyfish

Cnidarian Diversity Hydrozoa- Hydroids, Portugese Man-o-war Colonial