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Lion encounter - underwater poison

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It was a beautiful day at Malongane and the clear, calm Mozambican waters were slick as oil. We were going to dive Bass City, a formation of 5 rocks of almost identical size.

I saw him 18 meters down in the gin-clear water. At 6 feet long, he looked like a massive grey barrel – and he was close. His protruding eyes watched me impassively as his massive gills pumped the clear water through his slightly-open mouth through which my head and shoulder would comfortably fit.

His skin changed colour from slate-grey to blotched dark metal grey as I finned closer. I extended my arm and he moved away slightly but held his ground, his pectoral fins moving lazily. I began to stroke him softly while his beady stayed fixed on me. Bert was used to scuba divers and enjoyed the attention.

Bass City is famous for its resident "tame" potato bass Bert. There are 4 other large potato basses on this reef but Bert is the only one who will come and swim with you – and allow himself to be touched.

22 meters, and I finned toward and overhanging coral shelf to investigate. The mechanical sound of my regulated breathing was loud in my ears and it sent a stream of silver bubbles to the surface far above.

It was when I tried to use my hands to maneuver myself to peek under the ledge that I struck the Lionfish with my right hand.

Shocked, I watched a broad ribbon of blood fly from my fingers in the slight current. It looked purple in the diminished light.

The lionfish is one of the most venomous fish on the ocean floor ranking second only to stingrays in the total number of envenomations worldwide, with an estimated 40,000-50,000 cases annually. Lionfish have venomous dorsal spines that are used purely for defense, and when threatened the fish often faces its attacker in an upside down posture which brings its spines to bear.

Lionfish stings are usually not fatal to humans.


Photo Jens Petersen

When is stung, intense throbbing, sharp pain, tingling sensations, sweatiness and blistering will result. In worst case scenarios the symptoms may include headache, nausea, abdominal pain, delirium, seizures, paralysis of limbs, changes in blood pressure, breathing difficulties, heart failure and tremors, pulmonary edema, and loss of consciousness

A common treatment is soaking the afflicted area in hot water, as there is currently no anti-venom. However, immediate emergency medical treatment is still advised as some people are more susceptible to the venom than others.

The red lionfish (Pterois volitans) is a venomous coral reef fish in the family Scorpaenidae, order Scorpaeniformes. P. volitans is natively found in the Indo-Pacific region, but has become a huge invasive problem in the Caribbean Sea and along the East Coast of the United States, along with a similar species, Pterois miles. Red lionfish are clad in white stripes alternated with red, maroon, or brown. Adults can grow as large as 17 inches (43 cm) in length, while juveniles may be shorter than 1 inch (2.5 cm).[1] They can live up to 10 years.[2] It has large, venomous spines that protrude from the body like a mane, giving it the common name of the lionfish. The venomous spines make the fish inedible or deter most potential predators.

Lionfish reproduce monthly and are able to quickly disperse during their larval stage for expansion of their invasive region. There are no definitive predators of the lionfish, and many organizations are promoting the harvest and consumption of lionfish in efforts to prevent further increases in the already high population densities.

Reproduction

They are mainly a solitary species and courting is the only time they aggregate, generally one male with several females. Both P. volitans and P. miles are gonochoristic, only showing sexual dimorphism during reproduction. Similar courtship behaviors are observed in all Pterois species, including circling, sidewinding, following, and leading.

Lionfish are mostly nocturnal, leading to the behaviors typically around nightfall and continuing through the night. After courtship, the female releases two egg masses that are fertilized by the male before floating to the surface. The eggs are kept together by a mucus which disintegrates within a few days to release larvae. Data suggest Lionfish can reproduce monthly, through all seasons of the year.

Early life history and dispersal

Although little is known about the larval stage of the lionfish, some traits of the larvae include a large head, a long, triangular snout, long, serrated head spines, a larve pelvic spine, and coloration only in the pelvic fins. Larvae hatch 36 hours after fertilization.

They are good swimmers and can eat small ciliates just four days after conception. The larval stage is the shortest stage of the lionfish’s life, with a duration of about one month.

Venom

Lionfish venomous dorsal spines are used purely for defense. When threatened, the fish often faces its attacker in an upside-down posture which brings its spines to bear. However, its sting is usually not fatal to humans. If a human is envenomed, that person will experience extreme pain, and possibly headaches, vomiting, and breathing difficulties.

A common treatment is soaking the afflicted area in hot water, as very few hospitals carry specific treatments.

However, immediate emergency medical treatment is still advised, as some people are more susceptible to the venom than others.

Predators and prey


Photo Alexander Vasenin

In its invasive range, few predators of the lionfish have been documented. Most larger Atlantic and Caribbean fish and sharks that should be able to eat the lionfish have not recognized them as prey, likely due to the novelty of the fish in the invaded areas.

Lionfish have, however, been found in the stomachs of Nassau and tiger groupers in the Bahamas.

The lionfish themselves are voracious feeders and have outcompeted and filled the niche of the overfished snapper and grouper. When hunting, they corner prey using their large fins, then use their quick reflexes to swallow the prey whole.

They hunt primarily from late afternoon to dawn. High rates of prey consumption, a wide variety of prey, and increasing abundance of the fish lead to concerns the fish may have a very active role in the already declining trend of fish densities. As the fish become more abundant, they are becoming a threat to the fragile ecosystems they have invaded.

Between outcompeting similar fish and having a varied diet, the Lionfish is drastically changing and disrupting the food chains holding the marine ecosystems together.

As these chains are disrupted, declining densities of other fish populations are found, as well as declines in the overall diversity of coral reef areas

Envenomation

Classic envenomation consists of one or more puncture wounds, each discolored by a surrounding ring of bluish tissue.

Immediate and excruciating and localized pain immediately follow envenomation. This pain may spread to involve the entire limb and regional lymph nodes, peaking at around 60-90 minutes and lasting up to 12 hours if untreated.

Subsequent swelling caused by fluid in your body’s tissues, redness or rash, and warmth may involve the entire limb. Stings rarely result in tissue necrosis in the absence of secondary infection as is the case in stingray envenomations.

Small blisters - particularly on the hands - may form and be followed by tissue sloughing, inflammation and loss of sensation around the sting.

Other symptoms may include, nausea, muscle weakness, shortness of breath and low blood pressure. Mild subsequent pain may persist for days to weeks.

The severity of envenomation depends upon multiple factors including the offending species, the number of stings, and the age and underlying health of the victim. Scorpaenidae stings are progressively more severe from Pterois (lionfish) to Scorpaena (scorpionfish) to Synanceia (stonefish).

Treatment

  • Gently remove visible spines

  • Apply direct pressure to sting area control bleeding

  • Administer pain relief medication

  • Transport for medical evaluation.

  • Stay alert to serious systemic symptoms and prompt institution of appropriate life-saving procedures, such as cardiopulmonary resuscitation (CPR) and treatment for anaphylaxis.

  • Most references recommend that initial therapy consist of immersion into hot water (upper limit of 114 degrees Fahrenheit or 45 degrees Celsius) after removal of visible spines and sheath, in order to inactivate the components of the venom that might otherwise cause a severe systemic reaction.


    Mitch Mitchell is a bow hunter, outdoorsman and the author of several books on African wildlife and survival

    The affected limb should be immersed in water no warmer than 114 degrees Fahrenheit, or 45 degrees Celsius. Be careful not to inflict thermal burns by placing a limb as a result of loss of feeling or decreased sensitivity as a result of pain into scalding water.

    Medical treatment may include antibiotics, cardiovascular agents and corticosteroids

    Source Wikipedia


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