A swarm of jellyfish swim the Panthalassic Ocean.
Contributor:Stocktrek Images, Inc. / Alamy Stock Photo
File size:51.9 MB (2.8 MB Compressed download)
Releases:Model - no | Property - noDo I need a release?
Dimensions:4920 x 3690 px | 41.7 x 31.2 cm | 16.4 x 12.3 inches | 300dpi
Date taken:23 May 2011
Photographer:Walter Myers / Stocktrek Images
A smack, or swarm, of jellyfish swim the Panthalassic Ocean 500 million years ago during the Cambrian Period. Jellyfish, also known as sea jellies, are free-swimming organisms from the phylum Cnidaria and may have been among the first mobile macro life forms to evolve on Earth. Their distinguishing feature is specialized cells that they use mainly for capturing prey. Their bodies consist of a non-living jelly-like substance, sandwiched between two layers of tissue that are mostly one cell thick. There are approximately 9,000 species of Cnidaria today.