One of a number of Lessepsian invaders – species which have found their way into the Mediterranean via the Suez Canal – the lagocephalus sceleratus belongs to the family of blowfish (tetraodontidae) which are characterised by carrying a deadly neurotoxin which can be fatal if their flesh is eaten. Known in Japan as fugu, certain types of blowfish are considered a delicacy there and chefs have to go through several years of rigorous training to learn how to remove the poisonous organs (chiefly the liver) so as to make the fish safe for human consumption. It is not clear whether the lagocephalus sceleratus comes into this category, but what is certain is that the fish should not be consumed under any normal circumstances.

The silver-cheeked pufferfish or toadfish, as it is called, is extremely dangerous if eaten because it contains the poison tetrodotoxin in its ovaries and to a lesser extent its skin, muscles and liver, which protects it from voracious predators. It becomes toxic as it eats bacteria that contain the toxin. This substance causes paralysis of involuntary muscles, which may cause its victims to stop breathing or induce heart failure. Fatal intoxications have been reported in Egypt, Israel and Turkey. (Wikipedia).

In addition to being poisonous to eat, the silver-cheeked toadfish is unwelcome in Mediterranean waters for two further reasons: it is highly invasive, having no natural predators in the Mediterranean, and it causes a lot of damage both to marine life and to the fishing industry. Lately it is also proving to be a hazard to humans.

A fast-spreading invader
Native to the Red Sea, where it lives on rocky bottoms from shallow coastal waters down to a 250 m depth, the silver-cheeked toadfish was first seen in the Mediterranean around 2003-4. Since then it has been caught off the coasts of Israel, the south of Turkey, in Cyprus, the south coasts of mainland Greece, Crete, and Rhodes. By the second decade of the current century it had been identified on the island of Lampedusa, on Malta, in the south eastern Adriatic and south west France. The furthest West it has been sighted is at the Straits of Gibraltar.

Having no natural predators the lagocephalus proliferates rapidly and is a voracious feeder, consuming native fishing stocks and even indulging in cannibalisation. Specimens caught recently weigh 2 to 3 kg – a size it achieves in 2 years – with some in Cyprus weighing up to 7-8 kg. Its name is derived from the Ancient Greek words for “hare” and “head”, a reference to its powerful beak-like jaws, which can chew through nets and fishing tackle – it has even been videoed biting chunks out of an aluminium beer can. Although it is not naturally aggressive towards humans, there have been some reports of the fish biting swimmers and inflicting deep wounds.

Government compensation schemes
Their predation of native fish stocks and the damage they cause to fishing equipment have resulted in the lagocephalus posing a real threat to the livelihoods of fishermen, especially in Cyprus and Greece. One possible solution is for governments to pay a bounty to fishermen for every specimen caught, thereby encouraging them to catch a fish which otherwise has no commercial value and turn them in to the authorities for destruction, in the hope of reducing their populations.

The first such scheme has been instituted in Cyprus, and according to a report in the Cyprus Mail, the Fisheries Department has announced that approximately 103,000 kg of the toadfish have been collected since the launch of a grant scheme in June 2024. Under the scheme, funded jointly by the European Fisheries Fund and the Cypriot government until the end of 2029, eligible fishermen receive €4.73 per kg of fish landed, and around €487,000 has so far been paid out to participants. Eleven collective groups representing approximately 150 professional fishermen have joined the programme.

The problem is currently receiving increased attention in Greece, with fishermen demanding government action over the threat to their livelihoods which the proliferation of the lagocephalus represents. On 20th June Ekathimerini reported: “Fishermen across Greece are demanding government help to combat an invasive species threatening their livelihoods … Stathis Evangelou, 29, who has fished Astypalaia’s waters since he was 9, says he catches up to 200 pufferfish daily, which destroy nets and gear while eating valuable catch.”

In fact a similar scheme to that in Cyprus is already under consideration by the Ministry of Rural Development and Food. On 22nd June Athensvoice.gr reported the Ministry’s General Secretary Spyros Protopsaltis as saying: “For some months we have been working on a scheme which we have submitted to the European Commission. We are looking at whether we can offer a higher price than in Cyprus … In discussions we have had with fishermen’s representatives, they have explained to us that the €4.73 being paid in Cyprus is not a strong enough incentive, with the increase in the cost of diesel and all the problems associated with operating costs.”

Another article on Ethnos.gr states that “tackling the problem will be based on a complex of interventions which will include scientific monitoring of the problem, recording of catches, location of areas where the species is concentrated and reproduces, collaboration with research organisations, evaluation of digital tools, as well as the creation of processes for the safe management of the collected biomass…. Experience [in Cyprus] shows that targeted harvesting can help to reduce the pressure exerted by the species on marine ecosystems and provide relief to fisheries, without constituting a sole and definitive solution.”

The threat to humans
The potential threat to humans has been publicised in the international press recently, with inflammatory headlines directed at Northern European holidaymakers such as The Telegraph’s “Voracious pufferfish wreak havoc on the Mediterranean – Beach resorts warn of sharp-toothed invaders that bite fishing nets – and swimmers’ fingers and toes”. As the accompanying article makes clear, attacks on swimmers are fairly rare, and have mainly occurred when people have approached the fish in the water or even tried to feed them. Reporting on 20th June, the Telegraph’s Rome correspondent Nick Squires said:

“An elderly Greek woman was bitten by a silver-cheeked pufferfish this week and required stitches to the wound. She was injured while swimming off a beach in the coastal resort of Varkiza, near Athens. The fish lunged at her unexpectedly and without provocation, according to Greek media reports. …
“Nota Peristeraki, an expert on the species from the Hellenic Centre for Marine Research, said: ‘If you see this fish approaching you, you really need to avoid it. Some attacks have happened when people have tried to feed or touch the fish. There have been a couple of cases of people losing a finger or a toe. That said, these are rare incidents. You are more likely to encounter a shark.’”

On 21st June, under the headline “Warning to holidaymakers over toe-chomping pufferfish found lurking in Mediterranean waters”, the Daily Mail ran the same story, adding: “Alexis Charalambakis, a fisherman in Crete, told the AFP news agency: ‘If one of these bites you, it will take your finger clean off. They are the destruction of the sea. They leave nothing behind. If this wasn’t my boat, I’d quit this profession for good. The situation is dire … we cannot survive.’”

What to do if bitten by a pufferfish
With the upsurge in reports about the dangers of the lagocephalus, the Hellenic Red Cross has published instructions about what do do if one is bitten by one, as follows:

Sources
https://cyprusmail.com
https://www.ekathimerini.com
https://www.athensvoice.gr
https://www.ethnos.gr
https://www.telegraph.co.uk