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Australian spotted jellyfish

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Australian spotted jellyfish
Phyllorhiza punctata.jpg
Scientific Classification
Binomial Name

Phyllorhiza punctata

White spotted jelly 2.jpg
Different angle of Australian white spotted jellyfish

The White-Spotted Jellyfish is a species of jellyfish known by the scientific name Phyllorhiza punctata . They are native to Australia, but an invasive species in many other areas. They are generally found in large swarms which can threaten their local ecosystem because of the amount of plankton they filter from the water. This deprives other species such as corals, anemones, and some whales of their food source. These jellyfish are a member of the Cnidaria family –“cnid” referring to the stinging barbs on their tentacles. Each tentacle is covered with cells called cnidocytes that can sting or kill other animals. Most jellyfish use their sting to hunt or for defense mechanisms. Some do not have tentacles at all. Unlike some other jellies, the sting contains only a mild venom that does not cause a serious reaction in humans. [1]

The White-Spotted Jellyfish has a beautiful body with white spots over their body. It has radial symmetry with two germ layers which are the ectoderm(innermost layer) and the endoderm(outermost layer). The White Spotted Jellyfish has a simple digestive system with only one opening. They reproduce both sexually and asexually. In most cases, adults release sperm and eggs into the surrounding water. They achieve movement by both floatation and relying on the oceans currents and winds. They excrete from their internal cavity, the coelenteron. They use muscle contraction of their bell, and muscular contraction of the tentacles to circulate seawater and nutrients. They don't have well developed resiratory system but their skin is so thin on the body and tentacles that the oxygen flows through their body and goes through to their vital organs, carbon dioxide is removed the same way. [2]

Body Design

The umbrella or bell of the Australian white spotted jellyfish

White spotted jellyfish has average of 45-50cm in bell diameter but there has been a maximum reported size of 62cm. Between 94% and 98% of its body is water. White spotted jellyfish uses the same opening to eat and expel waste. [3]

White spotted jellyfish has a semi-spherical transparent rounded bell. The bell is covered with white spots. The bell shape consists of a layer of epidermis (skin), gastrodermis (stomach lining), and a thick layer called mesoglea that produces most of the jelly and separates the skin from the stomach. [4] The eight radial canals communicate directly with the stomach and there are 8 thick transparent branching rhopalia (oral arms) which terminate with large bundles of stinging cells. 14 lappets are found in each octant of the bell. Sub-genital Ostia (small openings) are wider than they are high, and the circular sub-umbrella muscles are interrupted by the 8 radial canals. [5]

Life Cycle

Shows the life cycle of a typical Jellyfish, including the Australian Spotted Jellyfish.

The basic cnidarian reproduction cycle can be divided broadly into two parts. It involves an asexually reproducing polyp stage, alternating with a sexually reproducing medusoid stage (the "jellyfish stage"). This way of reproduction is known as "alternation of generations". This alternation of generations may facilitate the transport of jellyfish by shipping through ballast water (planktonic planula, ephyrae or medusa) or fouling (benthic scyphistoma or strobila).[6]

The scyphozoan reproductive cycle is typically dominated by the medusoid stage. Sexes are separate in the medusae and these produce haploid gametes that combine through external fertilization to form free-swimming planula larvae. The adult planktonic medusa is commonly referred to as a jellyfish. The planktonic planula larvae of the sexually reproducing medusa search out suitable settlement sites and leave the water column to normally settle to the bottom where it attaches and grows (which is the scyphistoma stage). It may then either directly form additional scyphistoma through a process of budding, and/or develop into a strobila, a benthic form which asexually produces and releases young medusa known as ephyrae, detach from the ends of the sessile scyphistomae in a process termed strobilation. Ephyrae develop into mature medusae over a period of usually several weeks.[7] One study concluded that small Western medusa and ephyrae grow in the early summer, but when researching in Brazil, they found that in the winter and spring, all sizes of Phyllorhiza punctata are present. The study concluded the cause of this was linked to extended photoperiod and seasonal high water temperatures.[8]

Ecology

A world map of the locations where the Australian Spotted Jellyfish has been sighted

The phyllorhiza punctata lives in warm temperate waters . and is often found in near shore waters. The jellyfish is native to the tropical western Pacific Ocean. It can also be located near the surfaces of murky waters near estuaries in harbors and embayments. One of the ways that this species has migrated is by attaching themselves onto the hulls of boats and are transported to different destinations.[9] The Phyllorhiza punctata also has a wide distribuation around the Australian costal lagoon waters and across the Indo-Pacific Ocean involving the Philippine archipelago. [10]

Although they look very graceful and harmless, the White spotted jellyfish is another kind of threat to marine ecosystems. They affect many other populations of organisms around them, especially because they are invasive to their new surroundings. The jelly fish also eats small fish and shrimp. White spotted jellyfish are like sponges in that they filter sea water in one day in search of food and nutrition. They feed mainly on microscopic plankton in large quantities in sea water. However, the problem with the fact that they are as much as 13,200 liters sea water filter every day. Additionally, White spotted jellyfish often found in large flocks, and the intake of plankton by a swarm of White spotted jellyfish can be very high. This means that their consumption of plankton is extremely great. Feeding on plankton is a beneficial and a crucial way for the jellyfish to survive, it has some rewarding effects, but most are harmful to its physical surroundings. The main reason for this is again its invasive qualities to the native environment. [11]

Invasive Behavior

The White Spotted Jellyfish often travel in large flocks together. They are native to Australia and the Philippines. They have been involuntarily migrated to other areas the reason is unknown but people speculate that they got trapped in the ballast tanks of marine vessels. Another hypothesis is that they attached to the bottoms of the ships and they ended up where they are. They have been found in many different places like Hawaii, California and the Gulf of Mexico. But they have been more of a problem in The Gulf of Mexico because they are found in massive amounts there. They each individually filter through about 13,200 gallons of sea water each day. Out of all the water they filter especially in large groups they take most of the plankton leaving almost none left for other marine animals living off of plankton too. Animals as diverse as Coral, Sea Anemones, and Whales are impacted, as well they negatively affect the shrimp industry. All depend on Plankton in this area. They have also [12] [13]

Control Efforts

No current control efforts.

Video

Movement of Australian white spotted jellyfish A slide show of information about the Australian Spotted Jellyfish

References

  1. Unknown. Australian White-spotted Jellyfish Houston Zoo Fast Facts. Web. Date-of-access 10/7/2014.
  2. Jaskula,Patrick. Invertebrate Project: The White Spotted Jellyfish "Biology 11 Blog".Web. Date-of-publication 19 December 2012.
  3. National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG). Phyllorhiza punctata (jellyfish)."Global invasive spieces database" .Web.Date of publication 24 May 2006
  4. Unknown. Australian White-spotted Jellyfish "Houston Zoo Fast Facts". Web. Date-of-access 12 Oct 2014
  5. Life of Sea. Life of white spotted jellyfish."Life of Sea".Web. Date of publication Friday, July 08, 2011.
  6. Lendenfeld, Von. Phyllorhiza punctata Guidebook of Introduced Marine Species of Hawaii. Web. Date-of-access 10/7/2014.
  7. Masterson, J. Phyllorhiza punctata Smithsonian Marine Sation at Fort Pierce. Web. Date-of-last-update June 13, 2007.
  8. Masterson, J. Growth Phyllorhza Puncata. Web. Date-of-access 10/12/14.
  9. Graham, W.H. Phyllorhiza punctata. Texas Invasive Species Institute. Web. 10-3-14.
  10. Pagad, Shyama. Phyllorhiza punctata (jellyfish). Global Invasive Species Database. Web. 10-12-14.
  11. Komentar, O. Life of White Spotted Jellyfish. Life of Sea. Web. 10-12-14.
  12. Life of Sea, Life of Sea. [1] Life of Sea. Date of publication Friday, July 08, 2011.
  13. Dickerson, Nathan. [2] Jellyfish-Facts. October 13, 2014.