Jellyfish

Share Top Five March 9, 2019

Jellyfish or 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. The bell can pulsate to provide propulsion and highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, the planulalarva can disperse widely and is followed by a sedentary polyp phase,More info:wiki

Below are photos and Images you may like:

#10 Jellyfish wash up near Oregon’s Haystack Rock at Cannon Beach,More info:statesmanjournal

CANNON BEACH, Ore. (AP) — Huge numbers of moon jellyfish have washed up as far as the eye can see around Haystack Rock on the Oregon Coast.

The Daily Astorian reported Thursday that it’s not unusual for the jellies to wash up after a winter storm or ocean upwelling.

But marine biologists are urging beachgoers not to touch them.

While moon jellies usually don’t sting, another kind of jellyfish called the Pacific sea nettle does sting — sometimes even after it’s dead.

Scientists are still studying the role of jellyfish in marine food webs and their impact on fishing.

#9 The Jellyfish Dance,More info:kuma1024

#8 10 Cool things you didn’t know about jellyfish,More info:cbc

#7 Seabirds find fine dining among jellyfish,More info:sciencemag

Seabirds may have unknowing allies in their hunt for fish. Several years ago, a Japanese seabird specialist now studying the effects of climate change on life in Alaska’s Bering Sea noticed that some birds seemed to target clusters of jellyfish. Last summer, he went back to Alaska and outfitted eight thick-billed murres (Uria lomvia), 45-centimeter-long black and white birds that nest on island cliffs, with the avian equivalent of a GoPro camera and a device that tracked their movements. Half of the resulting videos documented underwater excursions, which included 197 feeding events. In 85% of the birds’ U-shaped dives, they encountered the jellyfish Chrysaora melanaster (pictured above), a common species in that area, on their way back up. About one-fifth of the time, the birds altered their ascent to go after young fish hiding among the jellyfish, the seabird specialist and his colleagues report online in Biology Letters. The more fish hiding under the jellyfish, the more likely the birds were to attack, they note. In recent years, it seems that the number of jellyfish have been on the rise, fueling concerns that their voracious appetites for microscopic sea creatures might have a negative impact on the food web and that their density might alter how fish behave—young fish seek refuge among the jellies’ tentacles, for example—and consequently hamper the ability of predators to catch these fish. But this study shows the opposite can be true as well, with jellyfish creating more opportunities for sea birds. Next, the researchers plan to study murres in years when jellyfish numbers are down.

#6 JELLYFISH HAVE EVOLVED EYES AT LEAST 8 TIMES,More info:futurity

#5 THE UK JELLYFISH SURVEY,More info:outdoorswimmingsociety

Jellyfish are a bit like Marmite of the swimming world. Some people love them, the way they elegantly move through the water, the beautiful colours, the different varieties that visit UK shores and how they arrive in large blooms as summer arrives. However, as many UK jellyfish can leave a mild sting, swimmers also loathe them.

Love them or loathe them, you can help out the Marine Conservation Society (MCS) this summer by recording them! The MCS want to learn more about what is happening to jellyfish populations in UK seas. If you visit the seaside, walk along beaches, swim, dive or sail – you can help.

“Little is known about jellyfish in UK waters, but we do know that they are the staple diet of the threatened leatherback turtle,” says the MCS. “These spectacular reptiles are seasonal visitors to UK seas, migrating from their tropical nesting beaches, and analyses of stomach contents of dead leatherbacks stranded on UK shores have revealed that they feed on several species of British jellyfish. By comparing the distribution of jellyfish with environmental factors such as sea temperature, plankton production and current flow, we hope to understand what influences the seasonal distribution of jellyfish in UK waters.”