Preferred Scientific Name
- Rhopilema nomadica Galil, 1990
Preferred Common Name
- nomad jellyfish
Local Common Names
- Israel: hutit nodedet
Generate a print friendly version containing only the sections you need.Generate report
R. nomadica is a neritic epipelagic, swarming, planktotrophic jellyfish. It is native to the east coast of Africa and the Red Sea. It was introduced into the Mediterranean in the late 1970s through the Suez Canal and has spread along the Levantine coast, from Egypt to Turkey and Greece. It was estimated that in the summer of 1989 its swarms contained 5.5×105 specimens per square nautical mile. It is capable of delivering a painful sting.
R. nomadica is a medium-sized rhizostomid medusa. It has a nearly hemispherical umbrella, thickest centrally, thinning gradually towards margin. Exumbrella minutely granulate, granules fewer and blunter near margin. Margin of umbrella divided into 64 rounded velar lappets. Ocular lappets small, lanceolate, one third as wide as velar lappets. Subumbrellar circular muscles well developed, uniform. Arm disc prismatic, about one third of bell diameter, oral pillars quadrate. Distal corners of oral pillars prominently tuberculate. Subgenital ostium at each interradius kidney-shaped, as wide as oral pillar. A pear-shaped, tuberculate papilla interradially on subumbrella, opposite ostial opening. Eight pairs of large, deeply bowed scapulets arise from adradial sides of armdisc; underside concave, smooth; upper side bearing frilled mouths and numerous filaments. Distal part of scapullets bearing long filaments, sometimes twice as long as scapulets. Each scapulet is divided, midlength, into two, with five appendages on each side. Eight adradial mouth arms stout, smooth, fused to midlength. Lower part of mouth arm divided into two triangular flaps, each flap distally tripartite and terminating in claw-like digitate processes. Ventrally, mouth arms bear numerous frilled mouths and long filaments. Lowermost end bearing a vermicular appendage terminating in a thin filament. Stomach cavity nearly octagonal. Gastrovascular system consisting of four perradial, four interradial and eight adradial canals interconnecting in a complex network of anastomosing vessels extending almost to bell margin. Four principal canals extend from lower part of stomach to radii entering each scapulet and mouth arm, then branching to numerous minute canals leading to mouths (Galil et al., 1990).
Colour in life icy blue. It can reach up to 100 cm umbrella diameter, but is commonly 30-50 cm in diameter.
R. nomadica is considered a native of east Africa and the Red Sea, although the exact limits of its range remain unknown (Stiasny, 1938, 1939).
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.Last updated: 10 Jan 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Israel||Present, Widespread||Introduced||1976||Invasive||Annual swarming in summer observed along the coast of Israel|
|Lebanon||Present, Widespread||Introduced||1989||Invasive||Annual swarming in summer observed along the coast of Lebanon|
|Turkey||Present, Widespread||Introduced||1995||Invasive||In 1995 observed in southeastern Turkey, in 1998 off Izmir, on the Aegean coast of Turkey|
|Greece||Present, Few occurrences||Introduced||2006||Invasive||Observed off Lakonikos Gulf. Greece, in summer of 2006|
In 1976 it was first collected of the coast of Israel (Galil et al., 1990), in 1989 it appeared off Lebanon (Lakkis et al., 1990), in 1995 it appeared off the southeastern Turkey (Kideys and Gücü, 1995), in 1998 off Izmir, in 2002 off Syria (Ikhtiyar et al., 2002), in 2003 off Cyprus, and in 2006 off Lakonikos Gulf, Greece (Siokou-Frangou et al., 2006).
R. nomadica is already found in the Levantine basin of the Mediterranean Sea. It may spread westwards along the north African coast, as it is environmentally similar to areas in which it has become invasive. Further spread is likely with increase in the sea surface temperature in the Mediterranean.
|Marine||Inshore marine||Principal habitat||Harmful (pest or invasive)|
R. nomadica has a two-stage life cycle consisting of the conspicuous, large, sexually reproducing swimming medusa stage and a benthic polyp stage (scyphistoma) that, because of its small size <2 mm), remains cryptic. Spawning occurs in summer. Fertilization is external and planulae are formed within hours. Settlement occurs within 3-4 days, and polyps developed within 3 weeks. Asexual reproduction occurs mostly through podocyst formation; polyps produce podocysts by growing stolons from the base of the disk. Polyps developed into polydisc strobilae within 45 days. The strobilation process is complete in 7 days; 5-6 ephyrae are formed on each strobila. Mature polyps may strobilate repeatedly. The development from the newly released ephyra (1.5-2 mm in diameter) to the young medusa (7-10 mm in diameter) may be completed within 2 months (Lotan et al., 1992).
The juveniles of the shrimp scad, Alepes djedaba, itself an invasive from the Indo-Pacific through the Suez Canal, are commonly found in association with R. nomadica, trailing in small schools with the jellyfish and when disturbed, taking shelter underneath its umbrella and among the filamentous mouth arms. It is possible that the great increase in the carangid’s abundance in the 1980s owes to the presence of R. nomadica sheltering juveniles.
R. nomadica tolerates a wide range of temperature from 16°C to 31°C. Swarms occur in the summer months when the sea surface temperature in the southern Levantine basin ranges from 26°C to 31°C.
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
|Parameter||Minimum Value||Maximum Value||Typical Value||Status||Life Stage||Notes|
|Depth (m b.s.l.)||Optimum||0-40 tolerated|
|Salinity (part per thousand)||Optimum||39.5 tolerated|
|Water temperature (ºC temperature)||20||26||Optimum||16-31 tolerated. Reproduction begins when temperatures reach 20|
Natural Dispersal (Non-Biotic)
R. nomadica has a negative impact on the southern Levantine fisheries. Coastal trawling and purse-seine fishing are disrupted for the duration of the swarming due to net clogging and inability to sort yield: “It is not uncommon that fishermen, especially purse seines, discard entire hauls due to the overwhelming presence of poisonous medusae in their nets” (Golani and Ben Tuvia, 1995). Jellyfish-blocked water intake pipes pose a threat to cooling systems of port-bound vessels and coastal power plants: in the summer of 2001 Israel Electric removed tons of jellyfish from its seawater intake pipes at its two largest power plants, at estimated costs of US $50,000 (Galil, 2007).
R. nomadica is cogeneric with the edible jellyfish, Rhopilema esculenta, a popular food in South-East Asian cooking (Hsieh et al., 2001). The latter species is also used for medicinal purposes (Omori and Nakano, 2001), such as treatment of high blood pressure and bronchitis and have been commercially exploited along the coasts of South-East Asia for more than 1,000 years (Morikawa, 1984; Hsieh et al., 2001; Omori and Nakano, 2001). The fishery is characterized by considerable fluctuations in annual catch and very short fishing season. Attempts to process and export R. nomadica from the Mediterranean to South-East Asian markets have not been successful thus far.
R. nomadica is distinguished from its near relative R. hispidum by its blunt tuberculation of the exumbrella and the mouth arms ending in vermicular filaments as compared with the sharply conical warts and “swollen club” appendages of the latter.
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Golani D; Ben Tuvia A, 1995. Lessepsian migration and the Mediterranean Fisheries of Israel. In: Condition of the world's aquatic habitats. Proceedings of the World Fisheries Congress. Theme 1 [ed. by Armantrout NB, Wolotira RJ, ]: Oxford & IBH Pub. Co., 279-289.
Ikhtiyar S; Durgham H; Bakr M, 2002. [English title not available]. (Contribution a l'etude dy scyphomeduse Rhopilema [Rhopilema] nomadica dans les eaux cotieres syriennes) Journal of Union of Arab Biologists Cairo A Zoology, 18:227-244.
Lakkis S; Avian M; Negro PDel; Rottini-Sandrini L, 1990. [English title not available]. (Les Scyphomeduses du Bassin Levantin (Beyrouth) et de l'Adriatique du Nord (Golfe de Trieste): comparison faunistique et ecologique) Rapports et Procès-Verbaux des Réunions, Commission Internationale pour I'Exploration Scientifique de la mer Méditerranée, 32(1):220.
Ikhtiyar S, Durgham H, Bakr M, 2002. Contribution to the study of the scyphomedusa Rhopilema [Rhopilema] nomadica in Syrian coastal waters. (Contribution a l'etude dy scyphomeduse Rhopilema [Rhopilema] nomadica dans les eaux cotieres syriennes.). Journal of Union of Arab Biologists Cairo A Zoology. 227-244.
Lakkis S, Avian M, Negro P Del, Rottini-Sandrini L, 1990. The scyphomedusoids of the Levantine Basin (Beirut) and the North Adriatic (Gulf of Trieste): faunistic and ecological comparison. (Les Scyphomeduses du Bassin Levantin (Beyrouth) et de l'Adriatique du Nord (Golfe de Trieste): comparison faunistique et ecologique.). Rapports et Procès-Verbaux des Réunions, Commission Internationale pour l'Exploration Scientifique de la mer Méditerranée. 32 (1), 220.
Israel: National Institute of Oceanography, Israel Oceanographic and Limnological Research, IOLR Management and National Institute of Oceanography Tel- Shikmona, P.O.B. 8030, Haifa 31080, http://www.ocean.org.il
Europe: DAISIE - Delivering Alien Invasive Species Inventories for Europe, Web-based service, http://www.europe-aliens.org
06/07/09 Original text by:
Bella Galil, National Institute of Oceanography, Israel Oceanographic &, Limnological Research, Israel
One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/