An Overview of the Atlantic Sea Nettle (Chrysaora quinquecirrha)

It is a bit of a fortune to jellyfish enthusiasts that one of the most attractive aquarium species, the Atlantic sea nettle (*Chrysaora quinquecirrha*), along with the newly classified Bay nettle (*Chrysaora chesapeakei*), are among the easiest to care for. The availability of captive-bred specimens, as well as high-quality live and prepared jellyfish foods, will almost surely lead to an increased presence of these beautiful animals in the marine aquarium hobby.

The Atlantic sea nettle (sometimes alternatively referred to as the East Coast sea nettle) has a geographic range that spans the Atlantic Ocean, especially along the U.S. East Coast from New England to the Caribbean. This species is commonly found in coastal waters but is distinct from the **Bay nettle (*Chrysaora chesapeakei*)**, which inhabits the brackish estuarine environments of the Chesapeake Bay and other nearby areas. The reclassification in 2017 separated these two species, acknowledging the unique genetic and morphological differences between them.

Both the Atlantic sea nettle and Bay nettle are born either male or female, but exhibit little to no sexual dimorphism (i.e., the bodies of males and females do not differ significantly in shape or size). These jellyfish experience two distinct body forms in their life cycle. The first, the polypoid stage, resembles a tiny sea anemone (usually only a few millimeters in length) that is attached to a hard substrate by a stalk. During this stage, it can reproduce asexually by budding, generating small, immature jellies called ephyra. Both species have multiple life stages, progressing from ephyra to the adult form, the medusa.

In its adult, medusa form, the Atlantic sea nettle’s body consists of an umbrella-shaped bell with long tentacles extending from the edges. The same is true for the Bay nettle, though the two species differ slightly in size and coloration. The Atlantic sea nettle has a bell averaging about 25 cm (10 inches) in diameter, with seven to ten tentacles extending from each of its eight lobes. Including its tentacles, it can reach up to 50 cm (20 inches) in length. Bay nettles are typically slightly smaller.

As an adult, the Atlantic sea nettle is a bit smaller in size than its Eastern Pacific counterpart, the Pacific sea nettle (*Chrysaora fuscescens*). Its coloration is also a bit different than its cousin, being paler (usually a ghostly white, but sometimes with light pink or yellow hues). Some wild specimens may have small whitish dots or brownish stripes radiating over the edge of the opaque umbrella cup. Captive individuals tend to be very pale, and can look very impressive under the glow of some forms of decorative colored lighting.

A potent venom in the stinging cells effectively immobilizes prey. Atlantic sea nettles feed primarily on copepods and other small crustaceans, but are also capable of capturing small fish, fish eggs, ctenophores, and even other jellyfishes. Due to its sting, it has relatively few natural predators; in the wild, it is preyed on by a small handful of creatures such as ocean sunfish, leatherback turtles, and larger jellies. Its sting rarely poses a serious danger to humans. Stings most often result in a rash that lasts for about twenty minutes. If the rash causes discomfort, misting (but not rubbing) the rash with vinegar can provide some relief.

Aquarists prize both species for their very active swimming behavior. Their frequent pulsations propel them efficiently through the water column while aiding in gas exchange. They generally prefer to swim against the prevailing currents but may alter their swimming patterns in the presence of prey. In the wild, Atlantic sea nettle and Bay nettle populations can concentrate in certain areas during the summer breeding season. It is believed that in these large congregations, they can exchange chemical signals.

The species is not currently under consideration for conservation status. Even so, captive-bred specimens (which have recently become available to aquarium hobbyists) are preferable as they have a much higher record of survivability than those that are harvested from the wild. Moreover, the sting from captive-bred individuals is said to be comparatively less intense. The maximum lifespan of this creature is still unknown, though they seem to live for about one to two years in captivity.

Compared to other jellyfish species, the Atlantic sea nettle and Bay nettle are considered to be easy to care for. If kept in an appropriately sized and maintained kreisel-style aquarium, they can thrive in captivity. When kept in large numbers, they may sometimes form tangled masses, only to untangle themselves naturally. They do not require special lighting, but good water quality is crucial. They should be kept at a tepid 68-77°F (20-25°C) and fed copepods, brine shrimp, and other specialty-prepared diets. Feedings should be small but frequent (two or more times daily). As long as water quality and food supply are consistently high, these jellies tend not to have major health issues in the home aquarium. Overall, Atlantic sea nettles and Bay nettles are among the most attractive, hardy, and interesting jellyfish species for aquarium hobbyists.

**References**

[1] “Chrysaora quinquecirrha (Sea nettle).” Animal Diversity Web. Retrieved Feb 5, 2017.

[2] “Chrysaora quinquecirrha.” Wikipedia.org. Retrieved Feb 5, 2017.