Chrysaora fuscescens
The Pacific sea nettle (Chrysaora fuscescens), or West Coast sea nettle, is a widespread planktonic scyphozoan cnidarian—or medusa, “jellyfish” or “jelly”—that lives in the northeastern Pacific Ocean, in temperate to cooler waters off of British Columbia and the West Coast of the United States, ranging south to México. The Pacific sea nettle earned its common name in-reference to its defensive, ‘nettle’-like sting; much like the stinging nettle plant (Urtica dioica), the sea nettle’s defensive sting is often irritating (possibly mildly painful) to humans, though rarely dangerous.
For other uses of "Pacific sea nettle", see Chrysaora melanaster.
The Pacific sea nettle has a distinctive, golden-brown bell—the main functioning ‘body’ or ‘head’ of a jelly—with a reddish tint. The bell can grow to be larger than one meter (3’) in diameter in the wild; however, most are less than 50 cm across. The long and spiraling, whitish oral arms (and 24 undulating, maroon tentacles) may trail behind the nettle as far as 15 feet (4.6 m).
Since about the mid-20th century, C. fuscescens has proven to be a very popular cnidarian to feature at aquariums (and even some zoos with aquatic exhibits), mainly due to the public’s fascination with their bright colors and extremely long tentacles. Additionally, the species is known for being quite low-maintenance in captivity, when provided with the appropriate water parameters and conditions. When these medusae are actively thriving under ideal conditions, they can even be easily bred via the culturing of polyps.[1]
Taxonomy[edit]
Johann Friedrich von Brandt described this species in 1835. The origin of the genus name Chrysaora lies in Greek mythology, with Chrysaor, brother of Pegasus, the son of Poseidon and Medusa. Translated, Chrysaor is Greek for "he who has a golden armament", in reference to the goldenrod color of the nettle’s bell.[2] The species name, fuscescens, is Latin for "dark into light".
Distribution and habitat[edit]
Chrysaora fuscescens is commonly found along the coasts of southern British Columbia, Washington, Oregon and most of California to Baja California Sur, México. Some sea nettles will range further north to the Gulf of Alaska, or west to Japan, and rarely into the Gulf of California. The populations reach their peak during the late summer. In recent years, C. fuscescens has become overly abundant off the coast of Oregon, which is thought to be an indicator of climate change. However, others suspect that the population is increasing because of human influences to coastal regions.[1][3] Industrial runoff to the ocean, as well as agricultural waste and other forms of human pollution (such as fertilizer and chemical plants), add considerable amounts of nutrients to the water when dumped into the ocean. This then feeds microorganisms and helps to fuel algal blooms, which subsequently fuels the entire food chain and potentially provides the nettles with enough food to see a population increase.