The Magic of Electrifying Jellyfish
The ocean holds many treasures, and amongst some of the most colorful and electrifying are the different and many varieties of Jellyfish, they really are nature at its best.
Whilst the Jellyfish can cause a deadly and often painful sting, this is its defensive mechanism that allows them to survive in the ocean depths.
Page 4 of Nature at its best shows all these wonderful sea creatures in all their color, tentacles and rather transparent bodies.
Basically, Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria.
Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles although a few are not mobile, being anchored to the seabed by stalks.
Jellyfish are found all over the world, from surface waters to the deep sea. Scyphozoans (the “true jellyfish”) are exclusively marine, but some hydrozoans with a similar appearance live in freshwater. Large, often colorful, jellyfish are common in coastal zones worldwide. The medusae of most species are fast-growing, and mature within a few months then die soon after breeding, but the polyp stage, attached to the seabed, may be much more long-lived. Jellyfish have been in existence for at least 500 million years, and possibly 700 million years or more, making them the oldest multi-organ animal group.
Jellyfish are eaten by humans in certain cultures. They are considered a delicacy in some Asian countries, where species in the Rhizostomae order are pressed and salted to remove excess water. Australian researchers have described them as a “perfect food”, sustainable, and protein-rich but relatively low in food energy.
They are also used in research, where the green fluorescent protein used by some species to cause bioluminescence has been adapted as a fluorescent marker for genes inserted into other cells or organisms.
The stinging cells used by jellyfish to subdue their prey can injure humans. Many thousands of swimmers are stung every year, with effects ranging from mild discomfort to serious injury or even death; small box jellyfish are responsible for many of these deaths. When conditions are favourable, jellyfish can form vast swarms, which can be responsible for damage to fishing gear by filling fishing nets, and sometimes clog the cooling systems of power and desalination plants which draw their water from the sea.