Spineless As a Jellyfish

What makes something a Jellyfish? Take a second: On a blank sheet of paper write down all of the characteristics that identify a jellyfish. When you think of a jellyfish—what do you think of? Describe the picture in your mind Now: Draw the jellyfish you just described.

Jellyfish History Jellyfish have been around for over 650 million years There are more than 2000 known species Can be found everywhere from the surface of the water to the depths of the ocean

What is a Jellyfish? Where do they fit in? A jellyfish is not a fish at all, it is an invertebrate in the phylum Cnidaria Cnidarians are a group of invertebrates that have stinging tentacles This includes corals, anemones, and JELLYFISH

Cnidarian Characteristics All Cnidarians share the following characteristics: Invertebrates (no backbone) Radial symmetry (tentacles arranged around a central mouth) Tentacles Only 2 cell layers Saclike digestive tract (in and out the same way) Simple nervous system (nerve net)

Bounce on the Tops The top of the jellyfish is called the medusa It is made of 2 cell layers Epidermis (outside) and gastrodermis (inside) In between the layers is a jelly-like material called the mesoglea A jellyfish is 90% water

Jellyfish Movement Jellyfish float on the water because the mesoglea is less dense than the ocean Move by contracting the medusa in a rhythmic motion Very weak swimmers and will not swim after humans or prey

Living and Breathing Oxygen will diffuse directly INTO the cell membrane from the water Carbon dioxide and wastes will diffuse OUT OF the cell membrane into the water

Feed Me: Tentacles have 2 main functions: Tentacles: Gather food and Bring the food to the mouth and digest it in the cavity CNIDOBLASTS are the stinging cells IN the tentacles: Little barbs in the cells called NEMATOCYSTS poke into prey and disable them They can only be used once and then need to be replaced

Nematocyst The barbs inside the stinging cells (cnidoblasts) that are inside tentacles and contain toxins >Now watch it in slow motion!

Predators and Prey Predators (who eats jellyfish?): Tuna Sharks Turtles Prey (what do jellyfish eat?): microscopic plankton, fish larvae, other jellyfish

Making More Jellyfish The four-leaf clover on top of the jellyfish are the sex organs Sperm cells swim out of the mouth of the male and into the mouth of the female Egg cells are fertilized in the female ovary

Jellyfish Life Cycle Larva are called planula They attach to a substrate and develop into a POLYP The POLYP will mature and develop into a MEDUSA which is a free floating organism

Human Uses of Jellyfish Food: 12 different species of jellyfish are used in food in southeast Asia Bioluminescence: Scientists found a protein for bioluminescence in jellyfish and recreated it to help detect specific genes in cells

Jellyfish Blooms A jellyfish happens when ocean currents and other environmental events cause there to be groupings of thousands of jellyfish! Blooms can have a bad effect on people as they result in: More jellyfish stings Decline in tourism on coasts Decline in commercial fish supplies due to jellyfish feeding Clogging engines of boats, power plants and desalination plants

Jellyfish Stings Many jellyfish stings are not deadly and only cause irritation Some jellyfish venom can cause anaphylaxis (allergic reaction where you can’t breath)—which may result in death Box jellyfish stings can be deadly

Treatment of Jellyfish Stings Primary Goal of treating jellyfish stings: Prevent injury to rescuers How to treat Jellyfish stings: Inactivate nematocysts—using vinegar or salt water (do not use alcohol, ammonia, or urine) Remove tentacles attached to the patient - shaving the area with a safety razor or credit card also removes nematocysts

Largest Jellyfish Lion’s Mane Jellyfish Medusa can be up to 7 feet in diameter Tentacles can reach 120 feet

Smallest Jellyfish Irukandji Only 1.5 inches across Almost invisible

Most Toxic Jellyfish Box Jellyfish Most deadly venom in the animal kingdom (caused 5568 recorded deaths since 1954) Found in the warm waters of Australia and Indo-Pacific

Amnemonemomne Sea Anemones

Sea Anemone Characteristics Classified in the class Anthozoa (which means “flower animal”) Tentacles Radial Symmetry Nerve net Sessile (stationary) lifestyle

Feeding in the Sea Anemone Tiny organisms and small fish swim into the tentacles and are paralyzed Bring food to mouth Food is digested in the digestive sac Undigested food and wastes are eliminated through the mouth

Sea Anemone Life Cycle Sea anemones do not reach a medusa stage They live as a polyp, attached to a substrate Reproduction: Asexually - fission, regeneration Sexually - male and female sex cells combine

Symbiosis Symbiosis: a mutually beneficial relationship between different species Ex: sea anemones and clownfish Clownfish keep the anemone from being bitten by other fish Sea anemones protect the clownfish from predators

Predators and Prey Predators: grey sea slug, tompot blenny Prey: small fish, shrimp, sea stars

Sea Anemone Habitat Sea anemones are mostly found in rocky coastal areas When the tides go out, they can be found in tide pools

Sea Anemones vs. Jellyfish Both Jellyfish Sessile Symbiotic Relationships End at polyp stage Basic cnidarian characteristics Stinging Tentacles Radial symmetry Sac-like digestive tract 2 Cell layers Nerve net Medusa stage Free swimming