EPOW - Ecology Picture of the Week

The Lion's Mane That Swims

Lion's Mane Jellyfish (Cyanea capillata), Family Cyaneidae
Alaska, USA

Explanation:  This ocean swimmer trails a long and deadly mane, but it's no lion.  This is a lion's mane jellyfish, whose stinging tendrils can reach lengths of about 9 meters (27 feet) ... although some sources claim 36 meters (120 feet)!  Regardless, this is the largest jellyfish.  Divers beware!

I found this specimen washed up on the north shore of St. Lawrence Island in the far north Bering Sea of Alaska.  It was well over a foot in diameter.

Jellyfish are amazing creatures who "go with the flow" of the tides and currents but also are somewhat self-propelled with their pulsing bells and tentacles.  This species feeds largely on fish, wrapping its 8 clusters of up to 150 tentacles around its prey and stunning it with nematocysts (stinging cells).  One source reports that a specimen of lion's mane jellyfish captured and ate another species of jellyfish!

Lion's mane jellyfish are widespread in cold waters of the world.  

 
Information
     Hansson, L. J.  1997.  Capture and digestion of the scyphozoan jellyfish Aurelia aurita by Cyanea capillata and prey response to predator contact.  Journal of Plankton Research 19(2):195-208.