Jellyfish are believed to have existed for more than 650 million years and have done so with no life sustaining organs such as a heart, brain, or blood. Jellyfish belong to the phylum cnidarian and are grouped with corals, hydras, and sea anemones.
Jellyfish have no eyes and utilize chemosensory pits which allow them to only discern light from dark and their delicate bodies are comprised mainly of water.
The bodies of these invertebrates are unique in the animal kingdom because they are totally symmetrical with no left or right side.
The jellyfish is made up of primarily three body parts:
• The muscular bell or the umbrella shaped top which can be very colorful and moves the animal through the water by pulsing and jetting water with its bell.
• The tentacles which can extend and contract and what hold the stinging cells or nematocysts which sting anything which may come into contact with them.
• Oral arms which enable the jellyfish to begin the digestive process and slowly bring its prey, primarily plankton, to the mouth of the creature hidden under its “bell”.
The stinging cells, or nematocysts, of the jellyfish are located on the tentacles of the animal. These small microscopic barbs hold a protein based neurotoxin which can stun and paralyze its food. Some jellyfish stings can be very painful, while some can actually kill a human being, however, jellyfish found along our Southern California coastline have stinging cells which only cause mild irritation if the cells are ruptured when in contact with softer skin tissues such as the arms, belly, upper legs and other parts of our bodies.
If you are stung by a jellyfish immediately wash the wound with salt water. Never use fresh water or attempt to rub or scrape off the cells as this will break them and cause more discomfort and irritation. If you can’t face re-entering the ocean, find the nearest lifeguard and they can assist with a saline based solution to counteract the stinging. Some people do have allergic reactions with symptoms of troubled breathing and increased blood pressure which will necessitate calling 9-1-1.
Lastly, it is important to note the jellyfish tentacles and nematocysts can continue to sting even after a jellyfish is dead or lying on the beach. It is best to not touch jellyfish whether found in the water or on land.
For more fun facts about the ocean and beach environment please see one of your amazing lifeguards on your Encinitas Beaches.