Species Fact Profile: Pacific Sea Nettle (Chrysaora fuscescens)

                                                              Pacific Sea Nettle

                                            Chrysaora fuscescens (Brandt, 1835)

Range: Northeastern Pacific Ocean, from southern Canada to Mexico.  Occasionally seen in western Pacific, near Japan

Habitat:  Coastal Waters.  Usually found near the surface in shallow water, but can congregate in deeper water in warm weather

Diet:  Zooplankton, Crustaceans, Mollusks, Small Fish, Jellies

Social Grouping: Asocial, but found in large congregations

Reproduction: Capable of both sexual and asexual reproduction.  Females catch sperm released by males, fertilizing eggs they are holding onto.  Fertilized eggs are attached to her arms, then released as polyps which attach to solid surfaces.  Polyps replicate themselves to form nettles, then release themselves from the surface they are clinging to, undergo metamorphosis, and take on a drifting lifestyle

Lifespan: 6-18 Months

      Conservation Status:  IUCN Not Evaluated

• Jelly with a distinctive golden-brown, lobed bell, capable of growing up to 1 meter in diameter, though usually less than half that.  They long, trailing tentacles (white oral arms and about two dozen maroon tentacles) may be up to 4.5 meters long
• Swims using jet propulsion, pushing water through the bell to allow them to swim against the currents.  Usually prefers simply to float, however
• Catch prey with toxin-laden tentacles drifting in the water, with barbed stingers being released when prey is contacted.  The oral arms begin digestion as prey is transported to the mouth 
• Primary defense mechanism is the potent sting of the tentacles, but some predators seem to not be effected by it.  Predators include large fish, seabirds, cetaceans, and especially the leatherback sea turtle.  The sting is painful, but generally not dangerous, to humans (common name references the stinging nettle plant of Eurasia)
• Small crabs sometimes hide within the bell of the nettle for protection, and may sometimes nibble at their hosts
• Populations have been increasing and range expanding.  Both climate change and pollution (industrial and agricultural runoff dumping nutrients into the water) have been suggested as possible causes