1. Moon Jelly (Aurelia aurita): Moon jellyfish are common in coastal waters worldwide. They have a saucer-shaped, transparent body with four horseshoe-shaped gonads visible through the bell.
2. Lion's Mane Jellyfish (Cyanea capillata): The lion's mane jellyfish is one of the largest jellyfish species, with tentacles that can grow up to several meters long. They are found in cold waters in the Northern Atlantic and Pacific Oceans.
3. Portuguese Man o' War (Physalia physalis): Despite its name, the Portuguese man o' war is actually a colonial organism composed of several specialized individuals called zooids. They have a gas-filled float that keeps them afloat and long, stinging tentacles.
4. Comb Jelly (Ctenophore): Comb jellies are related to jellyfish but are not true jellyfish. They have a unique arrangement of cilia that create a shimmering effect when they move, hence the name "comb jelly".
5. Sea Walnut (Mnemiopsis leidyi): Sea walnuts are small, transparent sea jellies that resemble walnuts in shape. They are found in coastal and oceanic waters worldwide.
6. Blue Jellyfish (Cyanea lamarckii): The blue jellyfish is a large jellyfish species found in the Atlantic Ocean and the Mediterranean Sea. They have a deep blue or purple coloration and long, trailing tentacles.
7. Red-Spotted Jellyfish (Phacellophora camtschatica): Red-spotted jellyfish are found in the Pacific and Indian Oceans and are characterized by their red or orange spots on the bell.
8. Upside-Down Jellyfish (Cassiopea andromeda): Upside-down jellyfish are unusual in that they spend most of their time upside down on the ocean floor. They have a flattened bell and short, oral arms that they use to capture prey.
9. By-the-Wind Sailor (Velella velella): By-the-wind sailors are small, triangular-shaped sea jellies that float on the surface of the ocean using a sail-like structure.
10. Crystal Jellyfish (Aequorea victoria): Crystal jellyfish are small, transparent jellyfish that are native to the Pacific Northwest. They are known for their bioluminescent properties and have been used in research on green fluorescent protein (GFP).