Venomous fish are species of fish which produce strong mixtures of harmful to humans (called venom) which they deliberately deliver by means of a bite, sting, or stab, resulting in an envenomation. As a contrast, poisonous fish also produce a strong toxin, but they do not bite, sting, or stab to deliver the toxin, instead being poisonous to eat because the human digestive system does not destroy the toxin they contain in their bodies.[ Poisonous vs. Venomous fish: What’s the difference? Reef Biosearch. Retrieved 17 July 2009.]
There are at least 1200 species of venomous fish, [Smith WL and Wheeler WC (2006) "Venom Evolution Widespread in Fishes: A Phylogenetic Road Map for the Bioprospecting of Piscine Venoms" Journal of Heredity 97 (3):206-217.]
Venomous fishes carry their venom in venom glands and use various delivery systems, such as spines or sharp fins, barbs, spikes and fangs. The most common venom delivery system is via dorsal spines.[Grady, Denise Venom Runs Thick in Fish Families, Researchers Learn New York Times 22 August 2006.]
Examples
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The most venomous known fish is the reef stonefish.
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Reef Stonefish, Synanceia verrucosa (Bloch & Schneider, 1801) Australian Museum. Retrieved 21 July 2009.
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The lionfish is a venomous coral reef fish.
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The stargazer buries itself and can deliver electric shocks as well as venom.
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can sting and Stingray injury with their stinger, with such frequently occurring when people wade in shallow water and tread on them. Such encounters can be avoided by shuffling through the sand or stamping on the bottom, as the rays detect this and swim away. The stinger usually breaks off in the wound, and as it is barbed it can easily penetrate the skin but is difficult to remove once lodged into the victim. The stinger causes local trauma from the cut itself, pain and swelling from the venom, and possible later infection from bacteria. Occasionally severed artery or death can result.
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Another very well-known venomous fish is the Blenniiformes They have venom that contains the opioid-like enkephalin, phospholipase, and neuropeptide Y.
[Losey GS. 1972. Predation protection in the poison-fang blenny, Meiacanthus atrodorsalis, and its mimics, Ecsenius bicolor and Runula laudandus (Blenniidae). Pac Sci 26(2): 129-139.] Enkephalin and phospholipase both produce inflammatory responses and neuropeptide Y induces a severe drop in blood pressure to the effected area.
Antivenom
fish are very often involved in human injury, usually by accident, but few studies have been done to investigate the constituents of fish venom. Even fewer studies have been done to create
antivenom.
The only commercially available antivenom is for the Indo-Pacific stonefish, Synanceja trachynis Stonefish Antivenom (SFAV).
Biological and pharmacological importance of fish venoms
It has been found that the mucous and sting venom of
Potamotrygon cf. henlei, a species of stingray that is found in
Brazil, is toxic to mice that have nociceptive, edematogenic, and
proteolysis activities. Two peptides were isolated from the stingray venom, orpotrin, which causes
vasoconstriction, and porflan, which causes
inflammation. Knowing how these peptides are structured could lead to the development of a neutralization technique that could effectively act as an antivenom.
Of all the piscine venoms studied, they all produce profound cardiovascular alterations, both in vivo and in vitro. These changes stimulate the release of nitric oxide from the endothelial cells, smooth muscle contractions, and other effects of the atria. Piscine venoms also produce neuromuscular activity effects- depolarization of nerve and muscle cells. In addition, piscine venoms have strong Cytolysis activity. In experimental models and in Western Western blot analysis, all tested piscine venoms showed structural similarity, which could lead to the advent of an overarching antivenom or other novel uses.
See also
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