Jellyfish

Cnidarians - "stinging creature." Phylum Cnidarians- example: hydras, jellyfish, sea anemone, coral Soft-bodied, carnivorous animals that have stinging tentacles Simplest animal to have body symmetry (radial) and specialized tissues.

Specialized cells: Cnidocytes- stinging cells located along tentacles used for defense and to capture prey Nematocyst- poison filled, stinging structure in the cell that contains a tightly coiled dart Epidermis- outer layer of skin Mesoglea- middle gel substance Gastroderm- inner lining of “stomach”.

Dorsal = upper/back side Ventral = underside/ abdominal

Fun fact! They can’t sting through pantyhose

Life Cycle Two stages: polyp and medusa Polyp- Medusa- cylindrical body w/ arm like tentacles mouth points upward sessile Medusa- bell shaped body w/ arm like tentacles mouth points down motile

Essential functions for Cnidarians Feeding – Carnivorous Tentacles arranged in circles around their mouths Gastrovascular Cavity- digestive chamber w/ one opening like a “stomach” No circulation, relies on the diffusion of nutrients from “stomach” Respiration/ Circulation/ Excretion- diffusion

Essential functions for Cnidarians Response- sensory cells sense light or gravity, no brain but a nerve net

Essential functions for Cnidarians Movement Only certain stages of life are motile Move by jet propulsion

Essential functions for Cnidarians Reproduction- both sexually and asexually asexually- polyps (budding new polyps or medusas) sexually- in medusa stage (external fertilization).

Coral

Coral Facts Coral has a symbiotic relationship with algae Coral excretes waste to the algae Algae produces sugars for coral Algae is VERY sensitive to light, temp, pH, etc

Coral Facts Coral can be used for bones transplants