A poisonous fish that could be fatal if consumed has been spotted for the first time in Maltese waters, leading local researchers to call for an early warning system and an information campaign about its danger.
The silver-cheeked toadfish, or Lagocephalus sceleratus, is a member of a family that is represented by the better known blow or puffer fish, considered to be a delicacy in Japan, where it is served by specialised chefs.
However, the toadfish caught in Malta by a Maltese fisherman in August 2014, in the mouth of Ġnejna Bay, is actually “one of the most dangerous members of this family and, for this reason, its occurrence requires to be strictly monitored and promptly communicated to competent authorities to avoid health complications to humans”.
The specimen has been studied by marine biologists Andreina Fenech-Farrugia, Luca Castriota, Manuela Falautano, Ernesto Azzurro, Franco Andaloro and Alan Deidun and is now at the centre of a scientific paper they have published together.
This family of fish has received a lot of scientific attention over the years due to the poison in its tissues, known as tetrodotoxin.
This family has received a lot of scientific attention over the years due to the poison
The powerful neurotoxin is mainly found in the liver and gonads, skin and intestine of the fish, which, if ingested, can block nerve “function in mammals including humans, ultimately causing death by paralysis of the respiratory muscles”. The University of Malta was alerted to the find by the Veterinary Affairs and Fisheries Division after the fisherman informed the authorities of his dangerous catch.
It was caught using a bottom long-line, baited with cuttlefish, at a depth of 15 metres in a sparse meadow of sea grass also known as Posidonia oceanica.
The researchers pointed out that there was a direct relationship between environmental conditions and the speed of spread and adaptation of new settlers.
Water temperature is often considered the most important factor affecting this particular species and the “present warming trend of the Mediterranean waters appears to facilitate their westward spread from the already invaded eastern part of the basin”.
The rapid spread and successful growth in the Mediterranean Sea could be due to its “somewhat broad thermal tolerance” as this tropical species had already penetrated colder Mediterranean areas, such as the north Aegean sea.
The researchers said the presence and expansion of the fish within the Strait of Sicily “strengthens the case for a greater monitoring effort targeting non-indigenous marine species within the same geographical area”.
One possible way of doing this was by setting up of a trans-boundary observatory in the strait, they said.