Thursday, September 20, 2012

Jelly Fish

In general, jellyfish are an important indicator species for the health of the ocean. When they occur in great colonies, or blooms, it can signify increasing pollution, and an ecosystem that is out of balance.

On June 12, 2008, Hong Kong Post issued the special stamp set featured jelly fish species. The issue comprises of 6 postage stamps depicted each jelly species i.e:  Flower hat jelly, Octopus jelly, Brown sea nettle, Moon jelly, Lion’s mane jelly, and Pacific sea nettle.

Flower Hat Jelly

The flower hat jelly (Olindias formosa) is a species of jellyfish occurring in the West Pacific off southern Japan. Flower hat jelly is one of the most 14 beautiful jellyfish in the world.

Flower hat jelly is one of a rare species of jellyfish. These invertebrate animals living in coastal waters. Characterized by lustrous tentacles that coil and adhere to its rim when not in use, the flower hat jelly's bell is translucent and pinstriped with opaque bands, making it easily recognizable.

The flower hat jelly can grow to be about 15 cm  in diameter. Its sting is painful but non-lethal to humans. Its diet consists of mostly small fishes and some marine invertebrates.

The stinging cells of the flower hat jelly’s tentacle fringe cause pain, but not death. They can quickly coil and uncoil these tentacles when needed, to capture food, defend themselves against predators, and keep competitors at a distance. The flower hat jelly spends some time on the ocean floor, and some time swimming closer to the surface.

Octopus Jelly

Octopus Jelly  is actually a large jellyfish. It has eight long tentacles, hence the name "octopus". The edge of its large body has no tentacles, but each of its legs has a sticky feathery band which is made up of numerous mouths for catching food. This jellyfish is reported to have no sting.

Octopus Jelly can grow up to 100cms in diameter. They feed on tiny particles in the water, and can be seen all year round. When they move close to shore to breed they can form large pods and this sometimes results in stranding. They comes closer to the shore in the summer months but moves out to deeper water during the winter.

Brown Sea Nettle

Brown Sea Nettle or The northern sea nettle (Chrysaora melanaster), also called a brown jellyfish, is a species of jellyfish native to the northern Pacific Ocean and adjacent parts of the Arctic Ocean.
This jelly's medusa can reach 60 centimeters in length with tentacles growing up to three meters.The number of tentacles is up to 24 (8 per octant). It dwells at depths of up to 100 meters, where it feeds on copepods,larvaceans, small fish, large zooplankton, and other jellies.The sting is mild, although can cause serious skin irritation and burning.

Moon Jelly

Moon jelly or Aurelia aurita is a widely studied species of the genus Aurelia.The medusa is translucent, usually about 25–40 cm in diameter, and can be recognized by its four horseshoe-shaped gonads, easily seen through the top of the bell. It feeds by collecting medusae, plankton and mollusks with its tentacles, and bringing them into its body for digestion. It is capable of only limited motion, and drifts with the current, even when swimming.

Lion’s Mane Jelly

Lion's mane jellyfish remain mostly very near the surface at no more than 20 m depth, their slow pulsations weakly driving them forwards; they depend on ocean currents whereby the jellies travel great distances.

The lion's mane jellyfish (Cyanea capillata) is the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans.

The lion's mane jellyfish are most often spotted during the late summer and autumn, when they have grown to a large size and the currents begin to sweep them closer to shore.

Most encounters cause temporary pain and localized redness. In normal circumstances, and in healthy individuals, their stings are not known to be fatal. Common remedies include: vinegar, isopropyl alcohol, and meat tenderizer.

Pacific Sea Nettle

The Pacific sea nettle or Chrysaora fuscescens is a common free-floating scyphozoa that lives in the East Pacific Ocean from Canada to Mexico.

The Pacific sea nettle have a distinctive golden-brown bell with a reddish tint. The bell can grow to be larger than one meter (three feet) in diameter in the wild, though most are less than 50 cm across.

Chrysaora fuscescens are carnivorous animals. They catch their prey by means of cnidocyst (or nematocyst) -laden tentacles that hang down in the water. The toxins in their nematocysts are effective against both their prey and humans.For humans, its sting is often irritating, but rarely dangerous.

Chrysaora fuscescens feeds on a wide variety of zooplankton, crustaceans, salps, pelagic snails, small fish as well as their eggs and larvae, and other jellyfish. Chrysaora fuscescens is prey to many marine birds and large fish.

No comments:

Related Posts Plugin for WordPress, Blogger...