The Fascinating World Of Jellyfish

Probably the most impressive jellyfish invasion began in 1982 when a few, small baseball-sized hermaphrodite jellyfish got into the Black Sea, probably in the ballast water of a visiting freighter, found conditions to their liking, and began to reproduce in a major way. In order to explore the structure of the Jellyfish galaxies in 3D and calculate the timescales of their transformation, Dr. Callum Bellhouse of the University of Birmingham in the U.K. created interactive models that can also be experienced in virtual reality.
Essentially, the bell of a jellyfish is a fluid-filled cavity surrounded by circular muscles; the jelly contracts its muscles, squirting water in the opposite direction from where it wishes to go. Jellyfish aren’t the only animals to possess hydrostatic skeletons; they can also be found in starfish , earthworms, and various other invertebrates.



Because they are common in both temperate and tropical waters, they can tolerate temperature ranges anywhere between 42-88 F (6-31 C). Although they can survive in brackish water, a salinity level (specific gravity) of 1.023 will mimic their native marine environment.
The little nasties can swim in clusters and if you are caught in the middle of them, they can wrap their little tentacles around your neck, legs and arms and without protection you will receive stings received when thousands of microscopic spiny splinters poke through the skin of the unsuspecting victim.

Depending on the species these stings can be very painful, but apart from the occasional thought about how curious these animals look, few of us rarely consider these animals or indeed recognise them as living fossils, unchanged for over 600 million years.
Jellyfish also depend on a loose network of nerves located within their epidermal and gastrodermal tissue (outer and inner body walls, respectively) to detect touch and a circular ring throughout the rhopalial lappet located at the rim of their body.

jellyfish lack a central nervous system, a circulatory system, and a respiratory system Compared to vertebrate animals, they are extremely simple organisms, characterized mainly by their undulating bells (which contain their stomachs) and their dangling, cnidocyte-spangled tentacles.
This should not be surprising when considering the identical nature between plants and animals as pointed out by Frantisek Baluska, Dieter Volkmann, Andrej Hlavacka, Stefano Mancuso and Peter W. Barlow in Neurobiological View of Plants and Their Body Plan (Communication in Plants, Springer-Verlag Berlin Heidelberg 2006) in that both rely on identical sexual processes utilizing fusion between sperm cells and oocytes (female egg cells), both develop immunity when attacked by pathogens, and both use the same methods and means to drive their circadian rhythms (patterns of biological activity synchronized to day-night cycles).