A remora, often called a suckerfish, is a marine fish that uses a specialized organ to temporarily attach itself to larger marine animals (sharks, whales, or sea turtles). This behavior is primarily for transportation and access to food, not for causing harm. Remoras are not venomous, aggressive, or parasitic, but their attachment can cause minor friction injury to the skin. Removal requires a specific technique to safely break the vacuum seal they create.
How Remoras Attach
Remoras possess a unique, flattened, oval-shaped structure on the top of their head that evolved from their first dorsal fin. This organ, known as the suction disc, allows them to adhere to various surfaces. The disc is bordered by a fleshy lip of connective tissue that forms a vacuum seal when pressed against a surface.
Inside this disc are multiple paired rows of plate-like structures called lamellae, which the fish can raise and lower using internal muscles. When the lamellae are erected, they create subambient pressure under the disc, generating powerful suction. These lamellae are also covered with microscale bony spinules, which increase friction and prevent the fish from sliding off its host, especially when the host is moving quickly. The fish’s adhesion relies entirely on this combination of negative pressure and frictional resistance, as it does not bite or use hooks.
Step-by-Step Safe Detachment
The strength of the remora’s attachment is directly related to the vacuum seal and the friction created by the spinules. Attempting to pull the fish straight off will only tighten its grip and increase the likelihood of skin abrasions. The safe technique focuses on gently breaking the vacuum seal by sliding the fish or introducing water beneath the disc.
The first step is to remain calm and avoid sudden movements, as these can cause the remora to instinctively clamp down harder. Locate the fish’s head, where the suction disc is situated. Prepare to move the fish in the direction it is already facing, as the remora’s natural detachment mechanism involves swimming forward to release the seal.
To manually break the seal, place both hands on the fish and apply a steady, gentle pushing force parallel to the skin surface, sliding the fish along the body. Direct this shearing motion toward the fish’s head. This simulates its natural release action and helps break the seal without tearing the skin. Once the vacuum is compromised, the fish will release its hold with minimal resistance.
Another technique involves finding the perimeter of the suction disc and carefully introducing a thin, blunt object, such as a credit card edge, underneath the fleshy lip. The goal is to disrupt the vacuum seal by letting water or air seep in, not to pry the fish off. Once the seal is broken, the remora will detach instantly. Gently release the fish back into the water after removal.
Post-Removal Care and Safety
After the remora is detached, the area of contact may show minor abrasions, friction burns, or small red marks due to the micro-spinules on the suction disc. Immediately clean the affected area thoroughly with fresh water and a mild soap to remove any marine bacteria.
Apply an antiseptic solution or ointment to the abrasion to minimize the risk of infection. Keeping the wound clean and covered with a sterile bandage is advisable until the skin heals, even though the risk of disease transmission from a remora is very low. Avoid using harsh chemicals or vigorously scrubbing the area, which can worsen the abrasion.
Monitor the site over the next 24 to 48 hours for signs of infection, such as increasing redness, swelling, warmth, or discharge. Seek medical attention promptly if the wound appears deeper than a minor surface abrasion, continues to bleed excessively, or if localized infection develops. The minor skin irritation caused by a remora attachment usually heals quickly with simple first aid.