Sharks, often portrayed as solitary apex predators, navigate the ocean with a diverse array of marine life. Among these, remoras are unique fish known for their distinctive ability to attach to larger animals. This leads many to wonder about the interaction between these two species, particularly whether sharks view their attached companions as a potential meal.
The Commensal Connection
Sharks generally do not consume remoras, largely due to their shared existence, a form of commensalism. In this relationship, remoras benefit significantly, while the shark is typically unaffected or may even receive some advantage. Remoras attach to a shark’s body, usually on its underside or belly, using a specially adapted dorsal fin that functions as a powerful suction cup. This attachment provides remoras with free transportation across vast ocean distances, conserving their energy. Beyond mobility, the shark’s presence offers protection from potential predators for the smaller remora.
Sharks tolerate remoras because they pose little burden and can offer beneficial services. The remora’s streamlined body minimizes drag, ensuring the shark expends minimal extra energy. Some studies indicate that certain shark species may even slow down to allow remoras to attach, suggesting an understanding of the benefits. While the primary benefit is to the remora, the shark may gain from the removal of external parasites, dead skin, and food scraps, contributing to its overall hygiene. Despite this generally peaceful coexistence, there are rare instances where certain shark species, such as sandbar and lemon sharks, have been observed acting aggressively towards or even consuming remoras.
Remora’s Lifestyle and Diet
The remora’s ability to attach firmly to a host stems from a unique suction disc on its head, an evolutionary modification of its dorsal fin. This disc features a fleshy outer lip that creates a tight seal against the host’s skin, and ribbed structures inside grip the host’s surface, preventing slippage even when the shark moves at high speeds.
Once attached, remoras primarily feed on food scraps left behind by their host’s meals. They also consume ectoparasites and shed skin flakes. Remoras may also filter feed on plankton or eat copepods and small fish. This diverse diet allows remoras to thrive as opportunistic feeders, minimizing their own energy expenditure while benefiting from the host’s activities.
What Sharks Really Eat
Sharks are primarily carnivores with diverse diets depending on their species, size, and habitat. Their prey includes a variety of marine animals, such as fish, crustaceans, seals, sea lions, sea turtles, squid, and even other sharks. Some of the largest shark species, like whale sharks, are filter feeders that consume plankton. Sharks are often opportunistic predators, feeding on available live prey or carrion.