Box jellyfish number soar

Box jellyfish.

Box jellyfish.

Although the mauve stinger jelly (Pelagia noctiluca) does not seem to be in abundance this summer, other species of jellyfish are rearing their head, Alan Deidun, the biologist coordinating the Spot the Jellyfish campaign said this morning.

One notable example, he said, was the box jellyfish – Carybdea marsupialis – which has been sighted by numerous bathers over the previous few days and who alerted the Spot the Jellyfish team. Although being largely transparent, the species is still relatively easy to spot and to identify since, unlike other species of jellyfish, it does not have a spherical umbrella but a squarsih one, with four tentacles dangling down from its umbrella.

Despite being a stinging species and being a box jellyfish, it's stings are not fatal, as those of its notorious Australian relative – the sea wasp (Chironex fleckeri) – responsible for a number of mortalities on Australian beaches each year.

Dr Deidun said that last year, the Spot the Jellyfish team recorded Carybdea marsupialis just a couple of times and not in bathing areas – the surge in numbers of this species (for which at least 30 individuals have been sighted over the past few weeks alone) this year could be due to a variety of reasons, ranging from sea temperatures, sea currents and even possibly the paucity in mauve stinger (a competing jellyfish species) numbers.

The venom in box jellyfish is distinct from that in other 'conventional' jellyfish and is used by the jellyfish to protect itself against predators as well, such as the rabbit fish and turtles, besides for capturing prey, although turtles seem to be immune to the box jellyfish venom.

The species is generally considered as a warm-water one, being known from the Mediterranean, Gulf of Mexico and even the Pacific coast of the USA. If stung, bathers should immediately seek medical attentionand freshwater should not be applied as it exacerbates the sensation of pain.

The Spot the Jellyfish initiative is coordinated by Dr Deidun, Prof. Aldo Drago and staff of IOI-MOC, and enjoys the support of the Malta Tourism Authority (MTA) and of Nature Trust, Friends of the Earth, EkoSkola, the BlueFlag Malta programme and, as from this year, Sharklab.

The initiative follows a citizen science approach and relies on the collaboration of the general public, mariners, divers, and especially the younger generations through their teachers and parents, by recruiting their assistance in recording the presence and location of different jellyfish through the use of a dedicated colourful reporting leaflet.

The leaflet is being widely distributed, and can be directly downloaded from, which is replete with snippets and anecdotes about different jellyfish species.

Reports of jellyfish sightings can be submitted either through the ad hoc website, by sending in the ad hoc leaflet distributed to local councils, by sending an email to [email protected] or even by sending an SMS to 7922 2278. With the support of MTA, large posters have furthermore been projected on boards along major bays on both islands.

A jellyfish photography competition is also being organised, jointly with Din l-Art Helwa, with submissions being received by Dr Deidun ([email protected]) and Stanley Farrugia Randon ([email protected]).

The competition is set along two tiers – one for SCUBA divers and snorkelers having an underwater camera and one for those having a conventional camera and taking photos of beached or surface jellyfish specimens.

Winners of both categories will be announced during Notte Bianca and prizes include an underwater watch and an underwater camera.


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