Dogfish sharks are common, widespread sharks, recognized by their slender bodies and distinctive features. They possess unique dorsal spines, a significant part of their anatomy that plays a role in their marine environment.
Precise Location of Dorsal Spines
Dogfish sharks, such as the spiny dogfish (Squalus acanthias), have two dorsal fins, each preceded by a sharp spine. The first dorsal fin is positioned closer to the shark’s head, while the second dorsal fin is located further back along the body, nearer to the tail. These spines are situated on the upper part of the shark’s body, directly along the dorsal fins.
The anterior dorsal fin is typically larger than the posterior dorsal fin. Therefore, the spine preceding the first dorsal fin is generally more prominent. The spines are located immediately in front of each fin.
Characteristics of the Spines
The spines of dogfish sharks are sharp and pointed structures. For species like the spiny dogfish (Squalus acanthias), these spines are associated with venom glands at their base, which secrete a mild venom.
If a dogfish shark uses its spines defensively, the mild venom can be secreted into a captor. A puncture from these spines can cause pain, local swelling, and redness. The presence of this venom enhances the spines’ effectiveness as a defense mechanism.
Function and Significance
The primary role of the dorsal spines in dogfish sharks is defense against predators. When threatened or captured, the shark can arch its back, allowing it to pierce an attacker with its spines and inject venom. This action serves to deter potential threats such as larger sharks, cod, or seals.
The combination of the sharp spines and the associated venom provides an effective deterrent. This defensive capability offers the dogfish shark an advantage in survival within its marine habitat. The spines contribute to the shark’s overall defense mechanisms and aid in its movement through the water.
Safe Handling and Observation
When interacting with dogfish sharks, exercising caution is important to avoid injury from their spines. The spines are sharp and can cause injury if the shark is handled without care. It is advisable to avoid direct contact with the dorsal spines.
If a dogfish shark is caught, safe handling involves carefully unhooking it without touching the spine-bearing areas. Using tools like pliers for de-hooking can help maintain a safe distance. If an accidental puncture occurs, the wound should be treated promptly, as the spines of species like the spiny dogfish can deliver a mild venom.