Scientists have recorded six species of pufferfish in the Greek seas, all belonging to the Tetraodontidae family. Most entered the Mediterranean from the Red Sea through the Suez Canal in a process known as Lessepsian migration, named after the French diplomat Ferdinand de Lesseps, who oversaw the canal’s construction.
While all are considered non-native, they differ considerably in size, toxicity, and ecological impact.
Lagocephalus sceleratus (Silver-cheeked Toadfish)
The silver-cheeked toadfish is by far the most notorious and dangerous pufferfish in the Mediterranean.
Growing to more than one meter (3.3 feet) in length and weighing up to seven kilograms (15 pounds), it is a formidable predator equipped with four fused teeth that form a powerful beak capable of crushing crabs, shellfish, sea urchins, and even fishing hooks.
Its organs—particularly the liver, ovaries, intestines, and skin—contain tetrodotoxin (TTX), one of the most potent natural neurotoxins known. There is no antidote, and poisoning can lead to paralysis, respiratory failure, and death.
Because of its rapid expansion, the species is considered one of the Mediterranean’s most damaging invasive fish. It destroys fishing gear, consumes commercially valuable species, and has become increasingly common around Crete, the Dodecanese, the Cyclades, and the eastern Aegean.
Just days ago, an elderly woman was injured after being bitten by a silver-cheeked toadfish while swimming at a beach in Varkiza, south of Athens, highlighting the growing presence of the invasive species in Greek waters.
According to local reports, the fish bit the woman on the leg without warning while she was in the sea. She was taken for medical treatment, where doctors treated the wound with stitches.
Medical professionals have reminded swimmers that pufferfish possess exceptionally powerful beak-like jaws capable of inflicting deep lacerations.
Lagocephalus suezensis (Suez Pufferfish)
Smaller than its infamous relative, the Suez pufferfish typically reaches 20–30 centimeters in length.
It also contains tetrodotoxin, although generally in lower concentrations than L. sceleratus. Nevertheless, experts stress that it should never be consumed.
The species prefers sandy or muddy seabeds and feeds primarily on crustaceans and mollusks. It is now well established in the southeastern Mediterranean.
Lagocephalus spadiceus (Half-smooth Golden Pufferfish)
This medium-sized species can grow to around 50 centimeters.
Although less studied than the silver-cheeked toadfish, it is also regarded as potentially toxic and is not considered safe for human consumption.
It inhabits coastal waters and continental shelves, feeding on invertebrates and small fish. Like other pufferfish, its expanding range reflects the warming conditions of the eastern Mediterranean.
Torquigener flavimaculosus (Yellow-spotted Pufferfish)
One of the smallest invasive pufferfish, this species usually measures 10 to 15 centimeters.
Recognizable by its numerous yellow spots, it lives close to sandy bottoms and seagrass meadows.
Although it poses little direct threat to swimmers because of its small size, it contributes to the growing pressure invasive species place on native marine communities by competing for food and habitat.
Sphoeroides pachygaster (Blunthead Pufferfish)
Unlike the Lessepsian migrants, the blunthead pufferfish is believed to have entered the Mediterranean naturally from the Atlantic Ocean through the Strait of Gibraltar.
It inhabits deeper offshore waters and can reach 50 centimeters in length.
Human encounters are relatively rare, but the species is considered unsuitable for consumption because toxic compounds may also be present in its tissues.
Tylerius spinosissimus (Spiny Pufferfish)
The rarest of the six species recorded in Greek waters, Tylerius spinosissimus, is a small deep-water pufferfish seldom seen by recreational swimmers or fishermen.
Scientists know comparatively little about its ecology in the Mediterranean, but its appearance confirms the continuing arrival of tropical marine species into the region.
Why Their Numbers Are Growing
Marine biologists attribute the spread of pufferfish to a combination of factors:
- Rising sea temperatures are linked to climate change.
- The Suez Canal acts as a migration corridor between the Red Sea and the Mediterranean.
- The lack of significant natural predators in their new environment.
- Their remarkable adaptability to a wide range of habitats.
Today, pufferfish are no longer confined to the southeastern Aegean. Sightings have become increasingly common around Crete, the Cyclades, the Ionian Islands, and parts of mainland Greece.
Although incidents involving swimmers remain uncommon, marine scientists emphasize that the greatest long-term concern is ecological.
Pufferfish prey on native fish, crustaceans, mollusks, and cephalopods while competing with local species for food and habitat. Their powerful beaks also tear through fishing nets, damage longlines, and destroy catches, creating significant economic losses for professional fishermen.
For this reason, the spread of invasive pufferfish is regarded as one of the Mediterranean’s most significant marine conservation challenges—one that Greece continues to monitor closely as warming seas reshape the region’s biodiversity.
