It’s not hard to imagine where these moon jellies got their name. As delicate as they look, jellies are tough: They’ve been around for 600 million years, predating sharks and surviving multiple mass extinctions, including the one that killed the dinosaurs.
What makes jellies such survivors? Unlike fish, they’re able to absorb oxygen directly through their bodies, storing it in their tissues so they can hunt in deep waters. Baby jellies can develop from swimming larvae directly into adults, but they often settle down and turn into polyps. Polyps can go dormant if conditions get bad, survive months without food, and even clone themselves.
C. cephea, sometimes called the Crown Jellyfish, (although this name is confusing as it is also used for other species) is a “true jellyfish” (Class Scyphozoa) in the small family Cephidae.
It is one of three species in its genus, all found in the Indo-Pacific and East Atlantic. Cephea occassionaly drifts inshore but is mostly oceanic, broadly distributed in waters from the mid-Pacific through the Indo-Pacific to the Red Sea, and in the Atlantic off West Africa. It is a large jellyfish, reaching 50-60 cm in diameter, with multiple wart-like projections on top of the central mound of its bell, which is surrounded by a moat.
Sugiura (1965) studied the life history of Cephea cephea in detail from planulae larvae collected from the oral system of females caught off Japan, reporting that this species reproduces frequently by budding of the scyphistome, while strobilation is monodisc, producing only one medusa from each scyphistome polyp...
Also known as the cabbage head jellyfish, the cannonball jellyfish is a species of jellyfish found from the eastern seaboard of North America all the way down to Brazil, with some populations found throughout the Pacific as well. Like other jellyfish the cannonball feeds mostly on zooplankton that it dispatches with its stinging nematocysts. The Cannonball also has a symbiotic relationship with L.dubia the Longnose Spider Crab (and a few fish/crab species)which resides on the jelly and feeds on passing zooplankton and sometimes the jelly itself. Like all jellyfish the cannonball jellyfish does sting and can cause immense pain in humans, it also has a mucus that it releases though its nematocysts as well, this mucus has a toxin that when released harms animals in the immediate area. This is used to stun prey and drive away predators and can be dangerous for humans as it can cause cardiac problems.
Red light does not reach ocean depths, so deep-sea animals that are red actually appear black and thus are less visible to predators and prey.
As you travel from surface waters to deeper waters, the quantity of light changes; it decreases with depth. The quality of light also varies with depth. Sunlight contains all of the colors of our visible spectrum (red, orange, yellow, green, blue, and violet). These colors combined together appear white.
Red light has the longest wavelength and, therefore, the least amount of energy in the visible spectrum. Wavelength decreases and energy increases as you move from red to violet light across the spectrum in the following order: red, orange, yellow, green, blue, and violet…
Also known as the black jellyfish, the black sea nettle is a species of true jellyfish found throughout the Western seaboard of the Pacific Ocean. Like other scyphozoan jellies the black sea nettle is carnivorous and will feed on any plankton that swim into its stinging tentacles. Its sting is powerful enough to kill or stun small animals but will only cause a painful sting that will last for about forty minutes in humans.
MBARI’s research expeditions sometimes yield encounters with extraordinary animals. During MBARI’s 2003 expedition to the Gulf of California, scientists spotted this massive jelly known as Stygiomedusa gigantea 1,300 meters below the surface of the Gulf. Its enormous reddish brown bell stretched about a meter (three feet) across and its oral arms were at least three meters (10 feet) long.
The researchers also collected a small fish in the genus Thalassobathia that was swimming over the jelly’s bell and among its billowing oral arms. In over 20 years of deep-sea dives, MBARI researchers have only seen Stygiomedusa jellies three times, so finding this drifting behemoth provided a truly memorable experience.
(via: Monterey Bay Aquarium Research Institute)
* look at that frisky little Lumpfish (Psychlorutes sp.) clinging to the side of the bell :3
What habitat a given organism lives in is one of those basic, immediate questions most of us have for a novel creature. That information is documented somewhere for every known species, but for most, the information is buried in a piece of text that you have to wade through (kind of like you’re doing now) to get to the answer you want:
Stalked jellyfish, hydrothermal vents.
An international research project called Environments-EOL is working to bring that information to the surface. They are currently refining a vocabulary of environment terms which will be used to process text sources, beginning with the EOL collection, to sort out which terms are applied to which species, and create a dataset which indexes species by their habitat. This will help us to complete biodiversity inventories for the different environments of the Earth, for the use of conservation science, ecological modelling, and anyone who wants to be able to inquire “What are all the species that live on the underside of polar ice?”
Glad you asked! In addition to all the hardworking plants and algae that are directly responsible for turning sunlight into energy, there are a number of animals that rely on photosynthesis by hosting symbiotic algae in their tissues. Corals are a familiar example, but not the only one.
The Golden Medusa gets about two thirds of its energy from the algae residing in its tissues. It can’t build a skeleton out of dissolved calcium carbonate like its reef forming cousins can, but there are advantages to its swimming lifestyle: During the day, it stays near the surface, where its algae can soak up the most sunlight. At night, it descends to deeper water with higher concentrations of nitrogen compounds- nutritious algae fertilizer.
This rare staurozoan, or stalked jellyfish (Haliclystus californiensis) is about 2 cm in length and was collected off the coast of California. Unlike the traditional bell-shaped floating jellyfish, staurozoans live attached to rocks or other hard surfaces and mostly live in cold water. They tend to blend in with their surroundings, so often go unnoticed except to those who seek them out.
Ephyrae, young jellyfish freshly sprouted from a polyp, look like small flower petals or, as the National Aquarium said, snowflakes! They are formed when a jelly in the polyp phase of its lifecycle reproduces asexually. The polyp is attached to a solid surface, and begins to bud off these small ephyra, which eventually mature into full-grown jellies.
Most people think of jellyfish as primitive floating balls of jelly and water that aren’t good at anything but stinging people. And while it is true that most jellyfish aren’t exactly “advanced” as far as animals go one class of jellies takes it to the next level. Box Jellies or Sea Wasps are cnidarians of the class cubozoa.
Named after their umbrella shaped medusae these small jellies are the one of the most venomous animals in the world. They are also the most developed as they sport a nerve ring and 24 sets of eyes which are located at the base of the bell. Most of these eyes do simple tasks like distinguished between light and dark. Amazingly they also have eight pairs of highly developed, almost human like, eyes which can detect the size and color of different objects. With these eyes the jellyfish can not only navigate its ocean environment with ease but it can also detect and avoid different obstacles.
Marine biologist Enric Sala spotted it off the coast of Chile, where he’s exploring the remote islands of Desventuradas.
“Something is approaching,” [submarine pilot Ari] says. Little by little, the figure starts to become visible in our lights but we do not know what it is. As soon as I hear him say, “This is incredible!” I know that this sighting is an exceptional one. A type of jellyfish, but with hard parts, like feet, that can turn and swim in all directions hypnotizes us. None of us have ever seen anything like it. We record it swimming for a half an hour thanks to the submarine’s true dance that Avi pilots to see this beautiful animal from every angle.
The most detailed account of what lives in this area is from 1875, and Enric hopes that cataloguing what lives in the area—including rare or unknown species like this jellyfish—will help Chilean scientists and conservation workers.