|More Ocean Resources
Jellyfish, marine animals without backbones (invertebrates), live in oceans around the world.
The name jellyfish refers to the animal's jelly-like bell, or box shaped body, that is often accompanied by tentacles.
Technically, jellyfish get classified as Cnidarians, a group of animals often distinguished by their stinging ability. They are also carnivores that use their long tentacles to paralyze their prey with toxic substances.
While most jellyfish sting, not all jellyfish stings are deadly to humans. The Portuguese man-of-war (Physalia physalis), pictured above, and various box jellyfish are probably the two most dangerous jellyfish found along the coastal waters of the United States.
Other native jellyfish such as sea nettles and purple-striped jellyfish are also known to cause painful stings.
The second picture shows the Sea Nettle Jellyfish, which packs a medium to painful sting.
Two species are showing up more often on both the East Coast (Chrysaora quinquecirrha) and West Coast (Chrysaora fuscescens).
Knowing what they look like onshore improves the probability of being able to avoid them and their sting. The top picture shows the rust colored marks of the East Coast species.
Avoiding jellyfish stings can be as simple as checking local beach reports about areas where large numbers of jellyfish (often called blooms) have been cited. Avoiding any jellyfish that wash up on the beach also helps.
In most instances of jellyfish stings, the pain can be dealt with by rubbing sand and/or splashing salt water on the affected area to remove any remaining tentacles, and them applying vinegar on the area to reduce the pain.
In the past decade increasing numbers of jellyfish blooms have been reported, and scientists are testing a variety of hypotheses related to their cause.
One such hypothesis assumes that increases in jellyfish populations results from declining fish populations. The reasoning starts with the assumption that many jellyfish species share a similar diet with fish.
As an area becomes over fished, the jellyfish move in to feed on the smaller fish and plankton still remaining.
© 2007-2011. Patricia A. Michaels (mano-of-war photo courtesy of alexkaris flickr)