While out doing a survey dive for the Cape RADD SCUBA for Science project, our divers had a rare encounter that left us in awe: a graceful John Dory (Zeus Capensis) fish swimming through the cool and calm waters at Long Beach in Simon’s Town. This predatory fish, known for its distinctive appearance and timid nature, captivated our senses and sparked a desire to share this incredible experience with you. Let’s dive into the mesmerizing world of the John Dory fish and relive the magic of that unforgettable encounter at Long Beach.

False Bay is a hotspot for biodiversity and is home to a multitude of species, each with its unique characteristics. Among them, the John Dory fish stands out as a true enigma, both in its appearance and behavior. This fascinating fish, with its striking features and elegant movement, has fascinated divers and marine enthusiasts with each encounter.

John Dory Fish swimming in Simons Town
John Dory as photographed by Cape RADD research divers at Long Beach, Simons Town.

The John Dory’s appearance is nothing short of extraordinary. Its flat, oval-shaped body, adorned with shimmering silver scales, seems tailor-made for graceful underwater maneuvers. However, what sets it apart is the prominent dark spot on its side, resembling an oversized eye. Folklore has it that this spot represents the touch of St. Peter’s finger, hence its alternative name, “St. Peter’s Fish.”

John Dory wallpaper

The habitat plays a crucial role in the life of a John Dory fish. These fish are found in coastal waters and are worldwide in distribution. They are particularly drawn to rocky reefs, sandy bottoms, and areas abundant in marine vegetation. It is in these habitats that they perfect their art of camouflage, effortlessly blending with their surroundings to become almost invisible to unsuspecting prey.

Elusive and solitary by nature, the John Dory fish prefers a life of solitude, often lurking among seaweed or concealed within rocky crevices. Their ability to change coloration allows them to seamlessly blend into their environment, waiting for the perfect moment to strike. With a swift motion, the John Dory ambushes its prey, engulfing it in its cavernous mouth using suction feeding aided by its remarkable eyesight and precise movements.

John Dory swimming from behind

The John Dory’s eyes are truly a marvel. Positioned on the front of its head, these large, forward-facing eyes grant it excellent binocular vision. This remarkable adaptation allows the fish to accurately track and capture its prey with astonishing precision. The commanding gaze of the John Dory’s eyes may deter potential predators, providing an added layer of protection.

John Dory fish reach an average length of around 30-40 centimeters and can weigh up to 2 kilograms. However, there have been reports of larger specimens reaching up to 60 centimeters in length. While not colossal in size, their presence is captivating, especially when witnessed firsthand in their natural habitat.

Cape RADD Research divers doing a fish survey
Cape RADD research divers performing an underwater fish survey.

If you find yourself drawn to the enchantment of the underwater world and wish to dive deeper into marine research and conservation, I invite you to join Cape RADD on a thrilling research dive. By participating in our research expeditions, you can contribute to the understanding and preservation of remarkable creatures like the John Dory fish. Join Cape RADD and make a splash in the realm of marine discovery.

Mark Fitzgibbon

Mark is a commercial SCUBA diver and marine scientist, currently working on a Masters degree focused on the complex relationships between marine parasites and their hosts. He has experience in animal health, microscopy and marine diseases, with a particular interest in sharks. Mark prefers to be in the water, and also volunteers at the Two Oceans Aquarium as a diver.


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.