Rhopilema nomadica or Nomad Jellyfish is a jellyfish that has been identified in the Northwest Pacific. The Nomad Jellyfish is a tiger-striped jellyfish that is around the size of a baseball, and if it were to sting a human, there would be little to no chance of survival.
Rhopilema nomadica is a neritic epipelagic, and its swarms are recorded at a distance of 2-4 km offshore. Occasionally it is swept nearer shore and into the intertidal zone. The Nomad Jellyfish has been found to be in high-density concentrations around Japanese waters at the Pacific coast and around the Korean Peninsula.
Many factors can contribute to Nomad Jellyfish’s migration throughout oceans, including currents, temperature changes, predation, and human effects.
Rhopilema Nomadica (Nomad Jellyfish) Characteristics’
The species was first described in 1873 by the French biologist Pierre Duchassaing de Fontbressin. Nomad jellyfish have a gelatinous umbrella that can reach up to 95 cm in diameter, with marginal tentacles reaching up to 60 cm. The radial canals through which water flows are clearly visible. The Nomad Jellyfish bell is clear and transparent but lacks the same color and pigmentation as other jellyfish. In the past, Nomad Jellyfish were used for various functions, including food and medicinal purposes.
Rhopilema Nomadica Life Cycle
Rhopilema nomadica are large (up to 95 cm), fragile jellyfish that move by crawling. They have a short life span of about one year and have three stages: a planula larva, polyp stage, and medusa jellyfish stage. Many factors can affect their success in each stage.
Rhopilema Nomadica /Nomad Jellyfish Sting
The Nomad Jellyfish has the largest head in the Rhopilema genus, making up approximately 70% of its body length. A large white spot is located near the head. The tentacles are a yellowish-orange color and are short and blunt. There are two types of stinging cells: nematocysts and cnidocytes. Cnidocytes are coiled, hair-like stinging cells and nematocysts are uncoiled, finger-like stinging cells. Most of the tentacles contain cnidocytes, except for the ones surrounding the mouth of the jellyfish.
These jellyfishes are well-known for forming massive swarms in the summer. Because of such outbreaks, R. nomadica has caused a socioeconomic problem in Israel by releasing venomous stinging cells.
The Nomad Jellyfish, most often measured, can reach a diameter of up to 90 cm, with 16 tentacles over in length. The bell is usually white or grey with countless small papulae. Like all jellies, it has no brain and moves in response to stimuli as well as currents and water movement. It is not poisonous but will sting if touched with the end of a boat’s anchor or similar object.
Rhopilema Nomadica /Nomad Jellyfish Size
Nomad Jellyfish can grow to be 95 cm in diameter with a bell length of 46 cm and a marginal tentacle length of up to 64 cm. Their bell is relatively transparent, and their edges are not clearly defined from other parts of their body. The average life span of Nomad Jellyfish is one year, although some have been known to live up to two years.
Nomad Jellyfish are found in the Mediterranean Sea and along the coast of South Africa. They are also found in other places worldwide, including Japan, Queensland, Australia, and New Zealand. They have also been seen off the coast of Texas and Florida in North America.
Rhopilema Nomadica Other Facts
There are two species of Nomad Jellyfish: Rhopilema nomadica and Rhopilema erythrée. Nomad jellyfish are most often found in the Mediterranean Sea but have been seen in many other parts of the world.
Nomad Jellyfish is primarily a coastal species that occurs near sandy beaches during most months of the year. However, they have also been found in estuaries and commonly enter tidal rivers where they can become trapped when low tide occurs. This can lead to death due to their inability to swim against currents of their own power.
Most sightings are reported between late spring to early autumn. They are also found in the Black Sea, Red Sea, Persian Gulf, and the Gulf of Mexico.