Note: These are 360° videos — press and hold to explore it!
These are organized by a classification scheme developed exclusively for Cosma. More…
jellyfish : the typically free-swimming, bell-shaped, usually sexually-reproducing solitary or colonial form of a cnidarian in which the whorls of tentacles lined with nematocysts arise and hang down from the margin of the nearly transparent, gelatinous bell — Webster
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 planula larva can disperse widely and is followed by a sedentary polyp phase.
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, mature within a few months and 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 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 also 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. These 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. — Wikipedia
Palau’s Jellyfish Lake reopens as thousands of jellyfish return (Maggie Hiufu Wong, CNN)
Ongeim’l Tketau Jellyfish Lake – Open to Visitors (Palau Gov)
Jellyfish Lake, Eil Malk island, Palau (Wikipedia)
Phys.org - latest science and technology news stories Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.
- Scientists resurrect 'forgotten' genus of algae...on July 1, 2021 at 5:34 pm
In the late 1800s, scientists were stumped by the "yellow cells" they were observing within the tissues of certain temperate marine animals, including sea anemones, corals and jellyfish. Were these cells part of the animal or separate organisms? If separate, were they parasites or did they confer a benefit to the host?
- The evolution of axial patterningon June 29, 2021 at 4:09 pm
Body axes are molecular coordinate systems along which regulatory genes are activated. These genes then activate the development of anatomical structures in correct locations in the embryo. Thus, the body ensures that we do not develop arms on our heads or ears on our backs. In many organisms, the main body axis is regulated by the β-catenin signaling pathway. In a new article in Nature Communications, a research group led by Grigory Genikhovich at the University of Vienna has found that the […]
- Paleonursery offers rare, detailed glimpse at...on June 28, 2021 at 3:00 pm
All life on Earth 500 million years ago lived in the oceans, but scientists know little about how these animals and algae developed. A newly discovered fossil deposit near Kunming, China, may hold the keys to understanding how these organisms laid the foundations for life on land and at sea today, according to an international team of researchers.
- Human-generated noise can contribute to deplete...on June 15, 2021 at 2:30 pm
When exposed to human-made noise, seagrass posidonia reveals permanent severe lesions in their sensory organs that sense gravity, which threatens their survival. This is the main conclusion of a recent study of the Laboratory of Applied Bioacoustics (LAB) of Universitat Politècnica de Catalunya BarcelonaTech (UPC) titled "Seagrass Posidonia is impaired by human-generated noise," which is published in Nature Communications Biology.
- Black holes help with star birthon June 14, 2021 at 3:14 pm
Research combining systematic observations with cosmological simulations has found that, surprisingly, black holes can help certain galaxies form new stars. On scales of galaxies, the role of supermassive black holes for star formation had previously been seen as destructive—active black holes can strip galaxies of the gas that galaxies need to form new stars. The new results, published in the journal Nature, showcase situations where active black holes can, instead, "clear the way" for […]