Rhopilema Nomadica Research Articles

Phenological shift in swarming patterns of Rhopilema nomadica in the Eastern Mediterranean Sea

Abstract Jellyfish (JF) swarms impact human wellbeing and marine ecosystems. Their global proliferation is a matter of concern and scientific debate, and the multitude of factors affecting (and affected by) their density and distribution merits long-term monitoring of their populations. Here we present an eight-year time series for Rhopilema nomadica, the most prominent JF species swarming the Eastern Mediterranean Sea. Reports were submitted by the public and within it a group of trained participants via an internet website between June 2011 and June 2019. Data collected included species, size, location, ranked amount and stinging. Swarms of R. nomadica prevailed in July and ended in August but were also prominent in winter from January to March. Both observations deviate from past swarming patterns described in the late 1980s, when summer swarms persevered until October and winter swarms were not documented. Climate change (increasing water temperature) and the westwards up-current spread of R. nomadica are discussed as possible explanations for this phenological shift. We further demonstrate how data obtained by Citizen Science is used to develop a swarming indicator and monitor JF in time and space, and propose a forecast based on these observations.

The Levantine jellyfish Rhopilema nomadica and Rhizostoma pulmo swim faster against the flow than with the flow

Jellyfish locomotion and orientation have been studied in the past both in the laboratory, testing mostly small jellyfish, and in the field, where it was impossible to control the seawater currents. Utilizing an outdoor water flume, we tested the locomotion of jellyfish when swimming against and with currents of up to 4.5 cm s−1. We used adult jellyfish from two of the most abundant species in the eastern Mediterranean, Rhopilema nomadica and Rhizostoma pulmo, and measured their pulsation frequency and swimming speed relative to the water. While pulsation frequency was not affected by the water velocity, jellyfish swam faster against the current than with it. This finding suggests that jellyfish possess a sensory ability, whose mechanism is currently unknown, enabling them to gauge the flow and react to it, possibly in order to reduce the risk of stranding.

Risk screening of the potential invasiveness of non-native jellyfishes in the Mediterranean Sea

The aim of the present study was to risk screen 45 jellyfish species (30 hydromedusae, 14 scyphomedusae, one cubomedusa) for their potential invasiveness in the Mediterranean Sea to aid managers in making informed decisions on targeting appropriate species for management. Using the Aquatic Species Invasiveness Screening Kit (AS-ISK), calibrated basic and climate-change threshold assessment scores of 6.5 and 12.5, respectively, were identified for distinguishing reliably between species that pose ‘low-to-medium’ and ‘high’ risk of becoming invasive in the risk assessment area. Using these thresholds, 16 species were classified as high risk, 23 as medium risk and six as low risk under current climate conditions. Whereas, under future climate conditions, 13, 30 and two species, respectively, were classified as high, medium and low risk, respectively. Upside-down jellyfish Cassiopea andromeda, Australian spotted jellyfish Phyllorhiza punctata, sea nettle Chrysaora quinquecirrha and Rhopilema nomadica were the highest-scoring species, with the maximum increase in risk score under predicted climate change conditions being achieved by C. andromeda.

The Spring Outbreak of the Invasive Scyphomedusa Rhopilema nomadica Galil, Spannier & Ferguson, 1990 in the Antalya Bay, the eastern Mediterranean

The present paper reports the spring bloom of the alien scyphomedusa Rhopilema nomadica in the Antalya Bay, in northern Levant Sea. This study also provides additional information with its distribution and biomass values of the species in the eastern Mediterranean.

Pediatric jellyfish envenomation in the Mediterranean Sea.

Several species of jellyfish native to the western Indian Ocean have entered the Mediterranean Sea through the Suez Canal. Since the late 1980s, each summer Rhopilema nomadica forms swarms as long as 100 km in the southeastern Levant and since the millennium aggregations of additional nonnative jellyfish have been sighted. The aim of this study was to evaluate children seen in the emergency department after jellyfish envenomations and to establish patterns of toxicity associated with this organism. A retrospective chart review was performed of all children presenting after jellyfish envenomations to the pediatric emergency department during the jellyfish swarming seasons (June-August) between 2010 and 2015. Extracted data included age, location of envenomation, pain scores, local and systemic manifestations, treatment provided in the emergency department and hospital, and disposition. Forty-one patients fulfilled the inclusion criteria; their ages ranged from 1 to 16 years and the median age was 9.4 years. Clinical manifestations were evident in all patients. Pain, present in 100% of patients, and an erythematous, whip-like, linear rash present in 87.8%, were the most common manifestations. The majority of 'burns' associated with jellyfish stings were first and second degree. The upper limb was affected in 34% and the lower limb was affected in 61% of cases. One patient suffered a sting to the abdomen and three patients suffered a sting to the face. Treatment in the emergency department included pain control, with nonsteroidal anti-inflammatory drugs and opiates, and antihistamines and topical corticosteroids in some cases. Nearly 49% of patients were seen during the summer of 2015 alone and seven patients in this group needed hospitalization. Reasons for hospitalization included systemic symptoms such as fever, chills, tachycardia, and muscle spasms. Two patients developed severe cellulitis, one patient had an anaphylactic reaction, and one was admitted to the ICU after suffering an anaphylactic reaction to a sting sustained while surfing. The prevalence of the jellyfish swarms and the severity of clinical manifestations because of their envenomations suggest that it should be considered as a health hazard in the Mediterranean Sea. We call for public health authorities in affected countries to initiate a health hazards database, familiarize medical and healthcare staff with the clinical syndromes, train medical and healthcare staff` in appropriate treatment, and initiate and continue public awareness campaigns.

Validation and redescription of the hyperiidean amphipod Brachyscelus rapacoides Stephensen, 1925 (Crustacea: Amphipoda: Hyperiidea: Brachyscelidae), a new record of association with the scyphozoan jellyfish Rhopilema nomadica Galil, 1990 (Scyphozoa: Rhizostomeae: Rhizostomatidae) in the Mediterranean Sea.

The hyperiidean amphipod Brachyscelus rapacoides Stephensen, 1925 is recorded from the scyphozoan jellyfish Rhopilema nomadica Galil, 1990, a new record of association for the genus Brachyscelus, as well as the first record of hyperiid infestation of a non-indigenous scyphozoan host. Because of some past confusion concerning the status of B. rapacoides and the closely related species B. rapax (Claus, 1871) a redescription of B. rapacoides and molecular analysis are provided in order to validate it as a species distinguished from B. rapax.

Citizen science: a successful tool for monitoring invasive alien species (IAS) in Marine Protected Areas. The case study of the Egadi Islands MPA (Tyrrhenian Sea, Italy)

The chief purpose of Marine Protected Areas (MPAs) is biodiversity conservation. The effects that invasive alien species (IAS) have on MPAs, and vice versa, are not yet fully known, even though assessing them is crucial for MPA planning. Management plans require sound knowledge of the pathways of introduction, the impact and current distribution of IAS. Monitoring plans are essential for preventing and reducing the risk of IAS introduction. In this respect, the involvement of citizen scientists in gathering data (validated by taxonomic experts) on the occurrence of IAS, that would otherwise be impossible to collect, may be crucial. We report on our experience of citizen science in the Egadi Islands MPA with the project ‘Caulerpa cylindracea – Egadi Islands’, aimed at monitoring the spread dynamics of the ‘sea grape’ C. cylindracea. The project registered 156 sightings and also allowed collection of records and information concerning other non-indigenous and cryptogenic species, e.g. the spotted sea hare (Aplysia dactylomela), the harpoon weed (Asparagopsis armata), the red sea plume (Asparagopsis taxiformis), the tube-building sabellid (Branchiomma bairdi), the blue spotted cornet fish (Fistularia commersoni) and the nomad jellyfish (Rhopilema nomadica).

Rediscovery of Sanderia malayensis and remarks on Rhopilema nomadica record in Pakistan (Cnidaria: Scyphozoa)

In this report, we record the rediscovery of Sanderia malayensis in Pakistani waters since the John Murray Expedition (1933‑34) who collected two small specimens off-Karachi, Pakistan. The specimens were described and we discuss the shape of gastric pouches contour. We also comment upon the newly recorded Rhopilema nomadica jellyfish from the region, and assume it to be previously recorded as Rhopilema hispidum.

Rediscovery of Sanderia malayensis and remarks on Rhopilema nomadica record in Pakistan (Cnidaria: Scyphozoa)

In this report, we record the rediscovery of Sanderia malayensis in Pakistani waters since the John Murray Expedition (1933‑34) who collected two small specimens off-Karachi, Pakistan. The specimens were described and we discuss the shape of gastric pouches contour. We also comment upon the newly recorded Rhopilema nomadica jellyfish from the region, and assume it to be previously recorded as Rhopilema hispidum.

New Mediterranean Biodiversity Records (October 2015)

The Collective Article “New Mediterranean Biodiversity Records” of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided per countries, listed according to a Mediterranean west-east geographic position. New biodiversity data are reported for 7 different countries, although one species hereby reported from Malta is overall new for the entire Mediterranean basin, and is presumably present also in Israel and Lebanon (see below in Malta). Italy: the rare native fish Gobius kolombatovici is first reported from the Ionian Sea, whilst the alien jellyfish Rhopilema nomadica and the alien fish Oplegnathus fasciatus are first reported from the entire country. The presence of O. fasciatus from Trieste is concomitantly the first for the entire Adriatic Sea. Finally, the alien bivalve Arcuatula senhousia is hereby first reported from Campania (Tyrrhenian Sea). Tunisia: a bloom of the alien crab Portunus segnis is first reported from the Gulf of Gabes, from where it was considered as casual. Malta: the alien flatworm Maritigrella fuscopunctata is first recorded from the Mediterranean Sea on the basis of 25 specimens. At the same time, web researches held possible unpublished records from Israel and Lebanon. The alien crab P. segnis, already mentioned above, is first formally reported from Malta based on specimens collected in 1972. Concomitantly, the presence of Callinectes sapidus in Maltese waters is excluded since based on misidentifications. Greece: the Atlantic northern brown shrimp Penaeus atzecus, previously known from the Ionian Sea from sporadic records only, is now well established in Greek and international Ionian waters. The alien sea urchin Diadema setosum is reported from the second time from Greece, and its first record date from the country is backdated to 2010 in Rhodes Island. The alien lionfish Pterois miles is first reported from Greece and concomitantly from the entire Aegean Sea. Turkey: the alien rhodophyte Antithamnion hubbsii is first recorded from Turkey and the entire eastern Mediterranean. New distributional data are also offered for the native fishes Alectis alexandrina and Heptranchias perlo. In particular, the former record is constituted by a juvenile of 21.38 mm total length, whilst the latter by a mature male. Cyprus: the rare native cephalopod Macrotritopus defilippi, and the alien crab Atergatis roseus, sea slug Plocamopherus ocellatus and fish Cheilodipterus novemstriatus are first recorded from the entire country. Lebanon: the alien crabs Actaea savignii and Matuta victor, as well as the alien fish Synanceia verrucosa, are first recorded from the entire country. In addition, the first Mediterranean record of A. savignii is backdated to 2006, whilst the high number of M. victor specimens observed in Lebanon first suggest its establishment in the basin. The Atlantic fishes Paranthias furcifer and Seriola fasciata, and the circumtropical Rachycentron canadum, are also first reported from the country. P. furcifer record backdate its presence in the Mediterranean to 2007, whilst S. fasciata records backdate its presence in the eastern Mediterranean to 2005. Finally, two of these latter species have been recently ascribed to alien species, but all the three species may better fit the cryptogenic category, if not a new one.

Radioactivity in three species of eastern Mediterranean jellyfish

Activity concentrations of 137Cs, 40K, 210Po, 210Pb, 234U and 238U were determined in umbrella and oral arms of three widely distributed jellyfish species; namely Rhopilema nomadica Galil, 1990, Aurelia aurita Linne, 1758 and Aequorea forskalea Péron & Lesueur, 1810 collected from February 2011 to January 2012 in four sampling locations along the Syrian coast (Eastern Mediterranean Sea). The results have shown significant variations in radionuclides activity concentrations amongst the species. The average activity concentrations of 40K, 210Po, 210Pb, 234U and 238U in the umbrella of R. nomadica species were higher than the average activity concentrations in the umbrella of A. aurita species by about 3.2, 1.4, 1.8, 3.2 and 3.2 folds, and A. forskalea species by about 45.5, 15.4, 19, 7.4 and 7.6 folds, respectively. The average activity concentrations of 40K, 210Po, 210Pb, 234U and 238U in oral arms of R. nomadica species were higher than the average activity concentrations in oral arms of A. aurita species by about 3.8, 1.7, 1.9, 2.8 and 2.9 folds, respectively. 137Cs activity concentrations were below the detection limit in all measured samples. In addition, activity concentrations of 137Cs, 40K, 210Po, 210Pb, 234U and 238U were also determined in 44 surface seawater samples and the activity concentrations ranged between 10.6 and 11.9 Bq l−1 for 40K, 1.1 and 1.4 mBq l−1 for 210Po, 0.5 and 0.7 mBq l−1 for 210Pb, 40.8 and 44.5 mBq l−1 for 234U, and 36.9 and 38.4 mBq l−1 for 238U, while 137Cs activity concentrations were below the detection limit in all measured samples. Moreover, the umbrella and oral arms readily accumulated 40K, 210Po, 210Pb, 234U and 238U above ambient seawater levels in the sequence of 210Po > 210Pb > 4 K > 234U and 238U. Concentration ratio (CR) values were relatively high for 210Po and 210Pb and reached 103 and 102, respectively for the jellyfish R. nomadica species compared to A. aurita and A. forskalea species. Therefore, R. nomadica can be used as biomonitor for these two radionuclides in the Eastern Mediterranean Sea. However, the obtained data can be considered the first reported baseline values for radioactivity in jellyfish.

The Enlargement of the Suez Canal and Introduction of Non‐Indigenous Species to the Mediterranean Sea

The Suez Canal is one of the most important waterways in the world – during the last year 17,148 ships passed through the Canal – reducing emissions, saving time, and operating costs to shippers. The rapid increase in ship size from the “Post-Suezmax” (> 12,000 TEU) to the latest container vessels (> 19,000 TEU) now requires enlargements of port facilities and canals. A project of this magnitude, and with potentially negative environmental outcomes, requires a transparent and scientifically sound “Environmental Impact Assessment” (EIA). An explicit obligation on Parties to the Convention on Biological Diversity (https://www.cbd.int/doc/ legal/cbd-en.pdf) was made to consider transboundary impacts on biodiversity, particularly those associated with invasive non-indigenous species. Although a nonbinding instrument, the “Rio Declaration on Environment and Development” sets forth important principles of international environmental law (UN 1992): States are responsible for ensuring that activities within their jurisdiction do not damage the environment of other States, and EIA, as a national instrument, shall be undertaken for proposed activities that are likely to have a significant adverse impact on the environment. To our knowledge, no Environmental Impact Assessment has been

Jellyfish outbreak impacts on recreation in the Mediterranean Sea: welfare estimates from a socioeconomic pilot survey in Israel

Jellyfish outbreaks in the Mediterranean Sea are part of an anthropogenic alteration of the marine ecosystem and have been documented as health hazards and threats to tourism. Their impacts on human welfare have, however, been poorly quantified. A socioeconomic survey, carried out in summer 2013, captures the impacts of an outbreak of Rhopilema nomadica on seaside recreation in Israel. Welfare losses are estimated based on per-visit value and expected change in visits patterns. We estimate that an outbreak reduces the number of seaside visits by 3–10.5%, with an annual monetary loss of €1.8–6.2 million. An additional 41% of the respondents state that their recreational activities on the beach are affected by the outbreak. Through a contingent valuation, we find that 56% of the respondents state a willingness to contribute to a national environmental protection program with an estimated annual benefit of €14.8 million. These figures signal an opportunity to invest in public information systems. A pilot study for adaptation was conducted in Barcelona, whose results confirm the importance of the welfare benefits of real-time public information systems. This study provides a benchmark against which the economic impacts of jellyfish outbreaks on coastal recreation and potential adaptation policies can be evaluated.

The invasive tropical scyphozoan Rhopilema nomadica Galil, 1990 reaches the Tunisian coast of the Mediterranean Sea

The alien Erythraean jellyfish Rhopilema nomadica was first recorded in Tunisia waters (Gulf of Gabes) in 2008. Subsequently it was sighted in the Bizerte Channel and Gulf of Tunis where it has been regularly observed since 2010 during summer and autumn months.

Purification and inflammatory edema induced by two PLA2 (Anch TX-I and Anch TX-II) from sea anemone Anthothoe chilensis (Actiniaria: Sagartiidae)

The Anch TX-I and II PLA(2) were purified from Anthothoe chilensis (Lesson, 1830) from the extract of the anemone after only two chromatographic step using molecular exclusion chromatography (Sephadex G-75) and reverse phase HPLC on μ-Bondapak C18 column. Both PLA(2) showed a molecular mass of ~14kDa determined by MALDI-TOF mass spectrometry and showed a high catalytic activity (data not showed). Although homologous with mammalian or snake venom group I PLA(2)s, Anch TX-I and II is sufficiently structurally different for the question of its placement into the existing PLA(2) classification scheme to arise. In addition, Anch TX-I and II, despite possessing many common structural features, also differ in some important structural properties. The amino acid sequence of both PLA(2) (Anch TX-I and III) showed high amino acid sequence identity with PLA(2)Rhopilema nomadica and Bunodosoma caissarum Cnidaria and PLA(2) of group III protein isolated from the Mexican lizard Heloderma horridum horridum and Heloderma suspectum. In addition, Anch TX-I and Anch TX-II showed high amino acid sequence identity with PLA(2) from group III also showed significant overall homology to bee Apis dorsata, Bombus terrestris and Bombus pennsylvanicus and PLA(2). We also investigated the in vivo edematogenic activity of Anch TX-I and Anch TX-II in a model of paw and skin edema in rats and observed that both are able to induce dose-dependent edema.

An updated review of alien species on the coasts of Turkey

This 2010 review of alien species along the coasts of Turkey represents a total of 400 alien species belonging to 14 systematic groups. The present paper also reports the first findings ofVanderhorstia mertensi in the Aegean Sea (Gökova Bay), Chama adspersa in the Sea of Marmara andMya arenaria in the Aegean Sea. A total of 124 new alien species was determined within the last 5 years. Mollusca had the highest number of species (105 species), followed by Polychaeta (75 species), Crustacea (64 species) and Pisces (58 species). The highest number of alien species (330 species) were encountered on the Levantine coast of Turkey, followed by the Aegean Sea (165 species), Sea of Marmara (69 species) and Black Sea (20 species). The Suez Canal (66% of the total number of alien species) is the main vector for species introductions to the coasts of Turkey, followed by the ship-mediated transport (30%). The majority of species (306 species, 76% of total number of species) have become established in the area, while 59 species are classified as casual (15%), 23 species as questionable (6%) and 13 species as cryptogenic (3%). One new alien species was introduced to the coasts of Turkey every 4 weeks between 1991 and 2010. The majority of aliens were found on soft substratum (198 species) in shallow waters (0-10 m) (319 species). Some species such asCaulerpa racemosa, Amphistegina lobifera, Amphisorus hemprichii, Rhopilema nomadica, Mnemiopsis leidyi, Hydroides spp., Ficopomatus enigmaticus, Charybdis longicollis, Rapana venosa, Asterias rubens, Siganus spp. and Lagocephalus sceleratus show high invasive characters, and have great impacts both on the prevailing ecosystems and humans.

The first confirmed record of the alien jellyfish Rhopilema nomadica Galil, 1990 from the southern Aegean coast of Turkey

The scyphozoan jellyfish Rhopilema nomadica Galil, 1990 has been observed in June 2011 in Marmaris Harbour, on the southern Aegean coast of Turkey. Information on previous records of this invasive species from the Mediterranean coast of Turkey is provided.

The westernmost record of Rhopilema nomadica (Galil, 1990) in the Mediterranean – off the Maltese Islands

In late autumn and early winter of 2004, two individuals of the Erythrean alien Rhopilema nomadica were sighted at two locations off the Maltese Islands, marking the westernmost records of this species in the Mediterranean Sea. Since only two adult specimens were ever reported from Maltese waters, in the species has yet to establish a reproducing population in the Sicily Channel. The record is considered as yet another hallmark of the warming trend of the Mediterranean Sea.

A new record of an alien jellyfish from the Levantine coast of Turkey - Cassiopea andromeda (Forsskål, 1775) (Cnidaria: Scyphozoa:Rhizostomea)

To date, three alien scyphozoan species were reported from the Eastern Mediterranean, but only one, Rhopilema nomadica, was reported from the Turkish coast. Recently, a second alien scyphozoan, Cassiopea andromeda, was collected on 20 July 2005 in Iskenderun Bay, SE Turkey.

First record of the scyphomedusa Rhopilema nomadica Galil, 1990 (Cnidaria: Scyphozoa: Rhizostomeae) in Greece

The scyphomedusa Rhopilema nomadica, recorded in July 2006 from Lakonikos Gulf, on the Ionian coast of Greece, is a Lessepsian alien established in the Levantine Sea. The jellyfish’s painful stings may pose a danger to swimmers. Because of its invasiveness and its impact it is considered among the worst invasive marine species in European Seas.