It has long been believed that sharks are the ocean’s most formidable predators. Their superior hunting skills and position at the top of the food chain give them an air of complete invulnerability. Beneath this image, though, lies a startling reality: sharks, like other marine life, are susceptible to a number of illnesses. Although many people think sharks are immune to cancer because of their cartilaginous skeletons and incredible strength, new research contradicts this notion. Sharks can and do suffer from a variety of terminal illnesses, despite their exceptional resilience.
As researchers continue to examine these apex predators, this understanding has grown in popularity over time. A more complex picture of shark health can be seen in their vulnerability to bacterial, fungal, and parasitic infections, despite their remarkable resilience to some environmental stressors. They are susceptible to the effects of human activity, which seriously impairs their populations and general well-being, in addition to these natural diseases.
Types of Terminal Illnesses in Sharks: A Deeper Dive
| Type of Illness | Cause/Agent | Impact |
|---|---|---|
| Bacterial Infections | Streptococcus agalactiae, infecting sandbar sharks | Fatal infection leading to death |
| Fungal Infections | Fusarium solani, Paecilomyces lilacinus, Exophiala pisciphila | Severe tissue damage, particularly in cartilage |
| Parasitic Infections | Nematodes, myxosporeosis in dogfish species | Contributes to morbidity and natural mortality |
| Fishing Gear Injuries | Retained fishing hooks causing chronic pericarditis | Leading to long-term complications and death |
| Environmental Contaminants | Vibrio spp., present in great white shark teeth | Pathogen transmission to other marine species, including humans |
Fungal and Bacterial Infections: The Unspoken Dangers
Despite their seeming invulnerability, sharks can get bacterial infections. Streptococcus agalactiae was found to be the cause of a deadly infection in a sandbar shark. After spreading throughout the shark’s body, this bacterium—famous for causing epizootic mortalities in fish populations—caused its death. Advanced molecular techniques were used to confirm this infection, underscoring the possible dangers that sharks may encounter from bacterial pathogens in their surroundings.
Shark vulnerability is also increased by fungal infections. In a concerning instance, it was discovered that juvenile bonnethead sharks had a fungal disease brought on by the cartilage-attacking strain of Fusarium solani. These kinds of fungal infections can cause significant tissue damage, endangering the sharks’ health and occasionally resulting in death. Understanding shark health is further complicated by the prevalence of fungal diseases in captive sharks.
The Effects of Human Parasitic Infections on Sharks
Another major threat to shark populations is parasites. Research on smooth and spiny dogfish has revealed a range of parasitic lesions, such as myxosporeosis and pancreatic nematodiasis. These parasites can increase morbidity and mortality and frequently interfere with normal organ function. This demonstrates how microscopic invaders can pose a threat to even the most resilient species.
The health hazards that sharks encounter are also indirectly caused by human activity. Fishing gear injuries are a serious problem, especially when released sharks still have hooks or other gear on their bodies. For instance, a retained fishing hook caused systemic lesions in a longfin mako shark, resulting in tissue and heart inflammation over time. The fact that this injury led to death demonstrates how human influence goes well beyond the direct harm caused by fishing.
Environmental Pollutants: An Increasing Risk to Sharks
Environmental pollutants have an effect on sharks in addition to physical wounds and illnesses. According to research, great white sharks’ teeth contain bacteria like Vibrio spp., which raises the possibility that sharks unintentionally infect other marine life. These pathogens not only endanger sharks but also have the potential to spread to people, particularly through shark bites. The connection between human safety and shark health emphasizes the necessity of more comprehensive marine conservation initiatives that tackle pollution and environmental pollutants.
The Immune System of Sharks Is More Complex Than We Previously Thought
Sharks were thought to be immune to cancer, but research has shown that this is not the case. They are not immune to disease because of their cartilage-based skeletons, which were once believed to shield them from tumors. However, the myth that sharks are immune to cancer because they lack bones originated from the observation that cartilage in certain animals inhibits the growth of tumors. Scientists have now disproved this myth and shown that sharks can get cancer.
However, there is still a lot of interest in the biomedical field regarding shark immune systems. Sharks have adaptive immune responses, and knowledge of how their bodies respond to wounds and infections can help advance human medicine. The immune systems that sharks employ to fend off infections are of special interest to researchers because they may hold the key to enhancing human immunity, particularly in the fight against cancer.
Shark Conservation: Safeguarding the Ocean’s Hardy Defenders
In addition to being essential to the wellbeing of marine ecosystems, sharks can teach us important lessons about adaptability and resilience. Even though their immune systems might not be as strong as previously believed, they are still amazing animals because of their capacity to endure in a variety of harsh environments. For shark conservation and the advancement of medical research that may benefit both humans and sharks, it is essential to comprehend the health issues that these animals face.
We can better safeguard these apex predators and the larger marine ecosystem the more we understand the diseases that impact sharks. Ongoing studies on shark immunity may yield ground-breaking findings that improve our understanding of how to treat infections in people. Meanwhile, to guarantee that sharks continue to flourish in our oceans, sustainable practices are crucial, such as lowering environmental pollution and minimizing injuries caused by fishing.
