Imagine walking barefoot in a tropical lagoon, the water is crystal clear, the sand seems smooth, but under you an animal can be hidden that does not want to be seen: the stonefish (Synanceia Verrucosa), also known as stone fish, Perhaps the most insidious of the fish that populate the seabed of the ado-Pacific and the Southeast Asia. His rocky appearance makes him almost invisible, a quality that allows him to surprise prey but also to transform himself into a danger for distracted bathers. The dorsal thorns are connected to poison glands capable of injecting a complex mixture of toxins, which can cause acute pain, edemi, serious systemic risks and even death in the most serious cases, leading researchers to study this fish with increasing attention and the development of a antidote. In recent years, scientists in different countries, from Australi to Japan, have shed light on fundamental aspects of his poison, explaining how the main toxin of this fish interfere with the functionality of the cells of the heart. Molecules have also been identified before in a stone fish poison, such as the aminobutirric gamma acid (Gaba), capable of interacting with human nerve receptors and explain theintense pain caused by the puncture. In addition to the poison in the glands, they are also present on the skin of the stone fish toxins Which, according to the researchers, are used to scare predators and prevent parasites. This fish, considered the most poisonous in the world, is not present in the waters of the Mediterranean Sea.
Where the fish that looks like a stone lives: characteristics and habitats
The stonefish (Synanceia Verrucosa) belongs to the genre Synanceia And it is sadly known as the more poisonous fish in the world. Stonefish populates the warm waters of theIndo-Pacificfrom Australian coral reef up to the coasts of Southeast Asia while they are not present in Italy and in the waters of the Mediterranean. They live immobile on the seabed, often half covered with sand, with the wrinkled and whispered skin that make them look like stones covered with algae. This disguise there protects against predators And it allows him to tend to ambush to small fish and crustaceans. It is precisely their ability to disappear in the marine landscape that makes them dangerous even for man: a distracted step is enough to trigger the dorsal thorns, connected to specific poison glands, ea inject the poison.
Who is point and what the symptoms are
The stings are recorded above all in Australiaa Singapore and in Japanoften between swimmers or fishermen who trample them without realizing it. A relationship of theAustralian Institute of Health and Welfare has estimated that almost One in ten cases of hospitalization by contact with poisonous marine animals, between 2017 and 2018, was due to these fish. Statistics show that the most frequent victims are young men, engaged in recreational or working activities on the seaand that intense pain almost always pushes to immediately seek hospital care.
The first unmistakable symptom of Stonefish’s bites is a very intense pain, even defined heartbreakingand not at all proportionate to the extent of the wound. Does not stop at the sting site, but comes to extend to the entire limb, causing cyanosis (the skin takes a bluish complexion) and edema, that is, swelling of the limb, until they compromise its functionality. Symptoms can also arrive at a systemic level and affect numerous organs with fever, deliriumtiredness and muscle paralysis, breathing difficulties, cardiac arrhythmias (irregular heart beats) up to heart failure and sometimes a fatal outcome.
Stonefish poison is extremely complex
It is not a single molecule that causes the symptoms of the stonefish sting, but recent searches have revealed that the composition of the stonefish poison is surprisingly complex. First of all there are great toxic proteins such as the stonustossine (SNTX) and the verrucotoxin (VTX) that act on the heart. A group of researchers led by K. Yazawa, at the University of Kagoshima in Japan, studied in the laboratory as the verrucotoxin on heart cells of small animals. They observed that toxin alters the passage of footballa fundamental mineral for the heartbeat: this makes the electric impulse that regulates the heart longer than normal and can trigger arrhythmiasthat is, irregular beats.
Next to these toxins, they were also identified small biological molecules. A job conducted in 2024 by Silvia Luiza Suggiomo and colleagues at the James Cook University (Australia) and the Ku Leuven (Belgium) has identified molecules such as choline, acetylcholine and gamminobutirrico acid (Gaba): It is the first time it was discovered in a fish poison. These molecules activate specific human receptors called Nicotinic and Gabaergic, involved in the modulation and transmission of painful signals. It is therefore possible that the presence of these molecules has a direct role in the neurological symptoms reported by the victimsexplaining the sudden and painful symptoms of the stings.
Antidote and therapies
The antivalen developed in Australia by the CSL Ltd. is The only antidote available in the worldwhich uses specific equine antibodies against the poison of Synanceia Trachynis. Jarrod Church and Wayne Hodgson laboratory studies of the Monash University (in Victoria, Australia), however, have shown that this serum is able to neutralize the pharmacological effects of other Stonefish species, including the Synanceia Verrucosa. However, the question of its non -uniform effectiveness remains open, because the composition of the poison It varies between species and geographical areas, and it is not excluded that in the future they need more “multi -specific” anti -anti or integrated with other therapies. Also, this antidote It is not always available in the affected places, So the first treatment remains the immersion of the limb in hot water (about 42 ° C), which seems to inactivate the toxin (also and effective in reducing the symptoms of the Stonefish poisoning.
The emblematic example described was the case in Malaysia, in Kuala Lumpur, where a thirty -year -old aquarist was point on one hand. Within a few hours the limb swelling to the point of risking blocking the circulation and damaging the tissues. Thanks to immediate care – precisely the immersion in hot water and one antibiotic therapy – The young man managed to avoid serious complications and completely recovered.
In addition to the poison injected by thorns, the Stonefish release these substances Ichthyocrinotossine directly from the skin. According to an analysis conducted by Danica Lennox-Bulow and colleagues at the James Cook University, these epidermal toxins could serve a discourage predators, prevent parasites e prevent incrustations. The authors propose that in the future they can also have industrial or medical applications.
Genetics and new future perspectives
A recent genomic sequencing projectconducted by the group of Tianle Tang and Bingmiao Gao at theHainan Medical University and the BGHI MARINE (China), reconstructed the chromosomal level of the Synanceia Verrucosa. The researchers identified clusters of genes associated with stonustossine, suggesting that specific duplications of these genes have favored the evolution of their high toxicity. These types of studies are not only used to clarify the evolution of toxins genes, but also represent a basis for identifying new bioactive molecules of toxin origin.
As a recent review by Von Reumont and colleagues on Modern Venomicsit is possible to connect the gene sequences to the physiological functions of the toxins and to test their potential in applications pharmacological. Among the most promising perspectives, the search for analgesics inspired by toxins that modulate the ionic channels, of compounds with properties anticancerof new molecules antimicrobial and innovative diagnostic tools. In this sense, the sequencing of the Stonefish genome is part of a wider vein: transforming the knowledge of the genetic diversity of poisons into concrete opportunities for medicine and biotechnology.
