How poisonous is a dogfish?

Dogfish sharks, also known as spiny dogfish, are small sharks that inhabit coastal waters around the world. There are several species of dogfish sharks, but they are all in the genus Squalus and family Squalidae. Some of the most common species include the spiny dogfish (Squalus acanthias), the Pacific spiny dogfish (Squalus suckleyi), and the spotted dogfish (Squalus megalops).

Dogfish get their name from their slender bodies and short snouts that resemble those of dogs. They typically have two spiney dorsal fins and lack an anal fin. Dogfish sharks are generally small, growing to around 3-4 feet long as adults. They have a varied diet, feeding on fish, squid, crabs and other small prey.

One question that is sometimes raised about dogfish sharks is – how poisonous are they? Sharks sometimes get a bad reputation for being dangerous predators, so are dogfish sharks toxic or venomous at all?

Do Dogfish Sharks Have Venom?

The simple answer is no – dogfish sharks do not produce venom and their bites are not poisonous. The spines on their dorsal fins can give a painful jab, but they do not inject any kind of venom.

Dogfish lack venom glands or any kind of delivery system that would allow them to transmit toxins to another animal. The spines on their dorsal fins are purely defensive – they do not connect to any venom producing organs.

This makes dogfish very different from some other groups of fish that are venomous, such as stingrays or stonefish. Those fish have modified fin spines that are connected to venom glands and can actively inject toxins that cause injury or death to predators. Dogfish do not have these venomous adaptations.

So if a dogfish shark bites or jabs you with its dorsal fin spine, it may hurt and cause some bleeding from the wound, but the injury will not be poisonous or venomous. There is no toxin introduced that could make you sick. The bite may risk infection like with any animal bite wound, but it does not contain any kind of poison.

Possible Toxicity From Eating Dogfish

While dogfish themselves are not venomous, there has been some investigation into whether their meat could contain toxins that are harmful if eaten.

Several species of shark accumulate high levels of heavy metals like mercury in their flesh from eating contaminated prey over their long lifespans. Consuming shark meat with very high mercury levels could pose a health risk for humans.

However, analysis of mercury and other heavy metal levels in the meat of spiny dogfish and other Squalus species suggests they do not accumulate particularly high concentrations. Their mercury levels are comparable to many other fish species and do not exceed safety guidelines for human consumption.

One study did find Pacific spiny dogfish meat sometimes tests positive for domoic acid, a naturally occurring neurotoxin produced by some types of algae. Domoic acid can cause amnesic shellfish poisoning in humans if consumed in high doses. However, levels found in spiny dogfish flesh were well below the safety limit for human intake.

So while dogfish shark meat should be consumed in moderation like any seafood, current research suggests it does not contain dangerously high levels of heavy metals, domoic acid, or other toxins that would make it poisonous to eat. Proper cooking and food hygiene practices should be followed to prevent any risk of microbial food poisoning.

Are Dogfish Shark Bites Dangerous?

As mentioned earlier, dogfish sharks do not have any venom, so their bites pose no poison risk. However, the bites can still be painful and lead to injury.

Dogfish have very small teeth – their bite strength is relatively weak compared to larger shark species. Most dogfish bites to humans occur by accident when fishermen are removing a dogfish from a net or line.

These bites generally result in minor cuts, puncture wounds, or lacerations to the hands, arms or feet. There are medical records of dogfish bites causing more severe gashes that required stitches or even surgery to repair damaged tendons or nerves.

While not venomous, dogfish bites do pose a risk of infection if not cleaned and treated promptly. As with any animal bite, doctors recommend thoroughly cleaning dogfish bite wounds with soap and water, using disinfectant, getting antibiotics if necessary, and watching for any signs of wound infection.

There are a few documented cases of dogfish bites resulting in more significant trauma. One report describes a fisherman receiving a deep, penetrating bite to the abdomen from a dogfish that resulted in intestinal perforation. Another describes a diver being bitten on the forearm down to the bone.

However, overall dogfish sharks are not considered an imminent threat to human safety. Records of serious injury from dogfish bites are rare compared to bites from larger, more aggressive shark species.

Being small in size with blunt teeth, dogfish simply lack the jaw strength and bite force required to inflict major traumatic damage on humans in most cases. While their bites can break skin and require medical care, the injury risk is relatively low compared to other shark species.

Are Dogfish Shark Dorsal Fin Spines Dangerous?

In addition to their teeth, dogfish sharks can also use their dorsal fin spines in defense. When threatened, they may whip or slash their dorsal fins to jab an antagonist with the spines.

These spines can certainly inflict painful puncture wounds. There are reports of fishermen handling dogfish getting jabbed by the spines, resulting in deep cuts and bleeding.

However, the venomous stingrays and stonefish mentioned earlier are uniquely adapted to break off and embed their fin spines in victims, injecting venom through the embedded spine. Dogfish fins do not function like this – their spines may puncture but do not break off or deliver toxins.

There is no venom gland connected to the dorsal fin spines of dogfish sharks. So while the spines can potentially cause lacerations if jabbed forcefully into skin, the wounds would not be poisoned. There would be a general risk of infection, but no venom introduced.

Records of severe injuries directly attributed to dogfish fin spines are scarce. There are isolated cases of ocular injuries reported when fishermen were accidentally jabbed in the eye. But overall, the bony fin spines of dogfish can certainly cause painful puncture wounds but are not highly dangerous compared to the stings of some venomous fish and invertebrates.

Treatment for Dogfish Shark Bites and Fin Spine Injuries

If you are unfortunately bitten or jabbed by a dogfish shark, these first aid steps are recommended:

– For bites, thoroughly flush the wound with clean, potable water to remove bacteria and debris
– Gently clean around the wound with mild soap and apply a disinfectant such as betadine
– For fin spine punctures, carefully clean and disinfect the entry and exit wounds
– Control any bleeding by applying direct pressure with a clean towel or cloth
– Cover the wound with a sterile bandage, adhesive bandage strips, or gauze wrap
– Immobilize or splint any bitten hand, arm, leg, or foot to restrict movement and reduce pain
– Take over-the-counter pain medication as needed, such as acetaminophen
– Monitor for any increasing redness, swelling, pus, warmth or red streaking from the wound, as these can indicate a worsening infection
– Seek medical care promptly, especially if the bite resulted in significant deep puncture wounds or lacerations
– Medical care may involve antibiotic medication, wound exploration and cleaning, sutures, or even surgery for very severe bites
– Be sure to get a tetanus shot within the last 5-10 years or get a booster if needed after the injury

While not venomous, dogfish injuries should be taken seriously to reduce the risks of complications like infection or trauma to deep tissues and bones. Prompt first aid and medical follow-up is advised. Most wounds should heal well with proper care.

Summary and Conclusions

In summary:

– Dogfish sharks have no venom and their bites contain no poison
– The spines on the dorsal fins can cause painful puncture wounds but inject no toxins
– Dogfish meat is not particularly high in mercury or other hazardous contaminants
– While non-venomous, dogfish bites can result in cuts, lacerations, and potential infection risk
– Serious trauma from dogfish bites is rare but possible depending on wound location and severity
– Dogfish fin spine wounds require first aid and monitoring to prevent complications
– Prompt cleaning, disinfection, bandaging and medical care will help optimize healing outcomes

So while not venomous or highly dangerous, dogfish sharks are capable of inflicting painful bites and fin spine injuries. Caution should be exercised when handling dogfish, and any wounds properly treated. Overall though, the small teeth and non-venomous spines of dogfish mean they pose minimal risk of life-threatening poisoning or injury to humans.

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