The sea nettle is a jellyfish found in the genus Chrysaora, and of the family Pelagiidae. There are various species of sea nettle jellyfish throughout the world, but they are all similar in some ways but vary slightly in others.

Featured image credit: Paul Harrison (CC BY-SA 4.0)



Appearance

The Atlantic sea nettle is typically smaller than the Pacific sea nettle and is known to have a wider range of colorations than its counterpart. The Atlantic sea nettle can be seen in pink, yellow, and a more pale hue. The Pacific sea nettle, however, follows a more distinctive color pattern. They are golden-brown with an element of red.

C. fuscescens‘s main section, or the bell, is mostly around 50 cm in diameter; however, they can grow up to 1 meter. Their tentacles have more room for growth as they can hit up to 15 feet. C. quinquecirrha is a smaller jelly, with its bell growing up to 40 cm.

The sea nettle has a medusa or bulb
The sea nettle has a medusa or bulb

Credit: Jim G from Silicon Valley, CA, USA, CC BY 2.0


Diet

Sea nettles have a broad diet as their hunting style is of a passive nature. This makes them accept a wider spectrum of prey. They are predators and carnivorous creatures. Small crustaceans, sea snails, zooplankton, small fish, fish eggs, larval fishes, other larvae, and even other jellyfish, are all on the menu.

Their hunting style consists of them leaving their tentacles hanging down in the water. These tentacles contain cnidocysts or stings that can paralyze their prey with their toxins. Once a creature is caught up in its tentacle web, the oral arms bring the prey to the mouth. The tentacles also digest the animal en route to the mouth.

Habitat

There are different types of sea nettle jellyfish, depending on the location. Some of the most significant species of sea nettle are the Chrysaora quinquecirrha, the Atlantic sea nettle or the east coast sea nettle, and the Chrysaora fuscescens, or the Pacific sea nettles. One of the less well-known species is the Chrysaora chesapeakei, or the bay nettle. This species is mainly found off the East Coast of the US, in the Chesapeake Bay.

The Japanese sea nettle is one of the species
The Japanese sea nettle is one of the species

Credit: Paul Harrison (CC BY-SA 4.0)

Reproduction

The life cycle, and reproductive cycle, of the sea nettle jellyfish, are very complex and dynamic. They can reproduce during multiple stages of their lifespan. For example, in their adult state, or medusa stage, the female will carry her eggs in her mouth until she captures the male’s sperm. This then fertilizes the eggs. The fertilized eggs continue to develop until they become polyps. They resemble flowers and get pushed out from the female into the open ocean.

They are also capable of asexual reproduction in their polyp stage once they anchor themselves to a solid surface. The polyps multiply themselves in identical forms with budding and are released once fully formed. They then grow as they swim.

Threats

Although climate change, and a shift in environmental conditions, are generally a threat to the majority of oceanic species, it seems to be having the opposite effect on the sea nettle. An overabundance of these jellies has been reported off the coast of Oregon. This is believed to be having a negative effect on the fish population as they are feeding on more and more fish as the numbers grow. Due to this population growth, it is hard to consider their conservation status as under threat.

Threats to Humans

Sea nettles do provide a level of threat to the human body if the situation arises. Normally, their toxic tentacles are not enough to be considered lethal. However, if a person was to be allergic to jellyfish stings, it could cause some serious issues and complications.

Facts about the Sea Nettle

  • The Pacific and Atlantic sea nettle vary in appearance but are otherwise very similar.
  • Their tentacles carry toxins that are fatal for many small ocean creatures.
  • They are capable of sexual reproduction in the young and adult stage of life.
  • Sea nettles hunt passively and use their tentacles to aid digestion.


FAQs

Are sea nettles poisonous?

Yes, sea nettles possess toxins called cnidocytes, which are lethal to their smaller prey and can stop predators in their tracks. They can cause issues with humans but are rarely lethal.

Are sea nettle jellyfish endangered?

No, in fact, the population of sea nettles is increasing. Due to this, they have not even been evaluated for the IUCN list.

Where are sea nettle found?

Different species of sea nettle are found in different areas of the world. The Atlantic sea nettle is found off the East Coast of the US and further down. The Pacific species is found off the Pacific coasts of many countries, from the US to Japan.

What class is the sea nettle in?

The sea nettle is in the class Scyphozoa, order Semaeostomeae, family Pelagiidea, and genus Chrysaora.