CNIDARIA

T HE S

T I NG

E RS

BY :

DO

UG

LA

NG

CHARACTERISTICS

• Inter-cell connections

• Carpet-like basement membranes

• Muscles

• Nerve net

• Statocyst

• Hydrostatic skeleton

ANATOMY

• Tentacle

• Nematocyst

• Mouth

• Gastrovascular cavity

• Bud

• Ocelli

DIGESTION

Eating-

• Predation

• absorb dissolved chemicals

• filter food particles from water

• Two-way digestion

Digestive waste-

• Enzymes reduce prey to slurry

• Gastroderm cells absorb nutrients

• Indigestible remains of prey go out mouth

RESPIRATION

• no respiratory organs

• Gas exchange over body surface

• Some pump water in and out of digestive cavity without opening mouth

INTERNAL TRANSPORT

• Do not have a organized internal transport

• Large gastrovascular cavity carries partially digested food through body

• Do not have any blood

• Gellationous material throughout their body

• The gellationous material is a storage unit for oxygen

EXCRETION

• Prey is broken down into slurry by enzymes

• Absorbs the nutrients

• After absorbed cells digest nutrients that takes a few days

• Releases the Indigestible remains out of the mouth

• Water currents remove cells’ internal processes (ammonia)

RESPONSE

• Nerve net

• Special cells cause contractions of muscle-like tissue• Movement of tentacles during prey capture

• Sensor organs

• No brain

• No eyes

MOVEMENT

• Only move when they are at the jelly fish stage.

• Hydrostatic Skeleton

• Some use jets to propel them

• Some are sessile

• Some sea anemones can slowly creep over rocks

REPRODUCTION

• Sexually

• Mass spawnings can make the water cloudy from so much gametes

• Water temperature lighting conditions trigger the spawning

• Asexually

• Polyps bud and occasionally split down the middle or above base

• Medusa split down the middle

• Larva stage, Polyp stage, Polyp strobilates, and Medusa stage

1-3 larva searches for site4-8 Polyp grows9-11 Polyp strobilates12-14 Medusa grows

EXAMPLES

• Sea Anemone

• Jellyfish

• Corals

• Sea Pens

• Box Jellies

FACTS (AKA FUN FACTS)

• The word Cnidaria comes from the Greek word “cnidos” that means stinging nettle

• Clownfish and Sea anemones have a symbiotic relationship

• Urinating on a jellyfish sting could make it worse or make it better

• Most corals do sting

• 130 different species have been recorded in Sydney Harbor

• Nematocysts fire tiny harpoon-like spears loaded with venom into prey.

• The firing of nematocysts is the fastest reaction in the animal kingdom.

LITERATURE CITED

• http://en.wikipedia.org/wiki/Cnidaria#Feeding_and_excretion

• http://cnidarianh.blogspot.com/2007/02/feeding-respiration-excretion.html

• http://cnidarianh.blogspot.com/2007/03/movement.html

• https://www.boundless.com/biology/textbooks/boundless-biology-textbook/the-musculoskeletal-system-38/types-of-skeletal-systems-215/hydrostatic-skeleton-exoskeleton-and-endoskeleton-812-12051/

• http://cnidarianh.blogspot.com/2007/02/internal-transport.html

• http://phylum-cnidaria.wikispaces.com/FUN+FACTS

• http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch7invertebrates/Invertwp/invert_wp_05/cnidaria/miles1/Cool.htm