Within the phylum Cnidaria Jelly Fish Cnidaria contains “stinging animals” which use nematocysts to capture petty Around 10,000 species in Cnidaria, nearly all living in marine waters Lacks basic organs such as heart, brain, kidneys, etc. Posses digestive sack (stomach) and stinging cells called nematocysts

Commonly known as Moon Jellies, or Saucer Jellies Size range between 5cm-40cm in diameter (2in-16in) Usually have large translucent bells, small, short tentacles, 4 gonads, and slow rhythmic pulsing Found worldwide Drift in ocean currents; they can travel far; therefore offspring are far reaching Moon Jellyfish Predators include sea turtles, fish, shore birds, and other jelly species Adults may live over a year, polyps can live up to 25 years

Taxonomy Kingdom- Animalia Subkingdom- Radiata Phylum- Cnidaria Subphylum- Medusozoa Class- Scyphozoa Subclass- Discomedusae Order- Semaeostomeae Family- Ulmaridae Subfamily- Aureliinae Genus- Aurelia Species- Aurelia aurita

Swim by pulsations of the bell-shaped upper part of the animal Swimming mainly functions to keep the Moon Jelly near the surface of the water rather than to make progress in the water The Moon Jelly swims horizontally, keeping the bell near the surface at all times, which allows tentacles to be spread over the largest possible area, to better catch food Swimming

Moon Jellies are found near the coast in mostly warm waters Can withstand temperatures as low as -6°C and as high as 31° C (21°F to 87°F) Occur in huge numbers Optimum temperature: 9°C to 19°C (48°F to 66°F) Known to live in brackish water with as low of a salt content as 0.60% Biomes- reef, tropical coastal, freshwater lake

Moon Jellies are carnivorous Feed on zooplankton Primary food includes mollusks, crustaceans, tunicate larvae, copepods, rotifers, nematodes, young polychaetes, protozoans, diatoms and eggs. (small plankton organisms) Also observed eating small hydromedusae and ctenophores

These foods collect on the surface of the animal, where they become entangled in mucus Food items are then passed to the margins They are moved along 8 separate canals, which are unique to the Moon Jelly These canals branch off and run into the stomach How Moon Jellies Eat

Sexual maturity in the Aurelia aurita commonly occurs in the spring and summer Their eggs develop in gonads located in pockets formed by the frills of the oral arms Their gonads are commonly the most recognizable part of the animal, because of their deep and conspicuous coloration Their gonads lie near the bottom of the stomach

Two main stages of life cycle: -polyp (asexual reproduction) -medusae (sexual reproduction) A male Moon Jelly releases sperm and the female takes it internally for fertilization The fertilized eggs go through development in the gonads until they are ready to be released When released, the larvae will spend a short period of time free swimming The larvae will settle in one spot as a polyp The polyp will reproduce asexually by creating clones of itself which will bud off the polyp and release them into the water column These polyps will eventually grow into a Moon Jelly and restart the cycle Alternation of Generation

moom.jpg the-month/664-moonjelly Sources