The Giant Swordfish Eyeball in Florida: Why This Mystery Should be Used to Fund More Marine Science

Occasionally a discovery is made that captivates the imagination. Last Wednesday, such a discovery was made when Gino Covacci stumbled upon a strange, spherical object, washed up on the tideline of Pompano Beach, in South-eastern Florida. Curious, the beachcomber kicked-over what he thought was some sort of white ball to discover a large, steel-blue eye gazing back at him. Presumably startled, Covacci decided to collect the baseball-sized structure and store it in a refrigerator, preserving the eye, thus enabling identification at the Florida Fish and Wildlife Conservation Commission. After receiving the organ, the commission uploaded a photograph onto Facebook, which sparked great interest among marine biologists and amateur nature enthusiasts, who debated the eyeball’s origins. Such curiosity and intrigue also reveals an interest many people have concerning the mysteries of the deep, and also our lack of understanding about the world’s largest environment.

Squid Speculations

Many observers on the internet as well as some experts wondered whether the eye belonged to a giant squid. With females growing to an estimated 13 metres long, giant squid have one of the largest eyes in the animal kingdom, possibly only smaller to the little known colossal or super colossal squids. Collectively known as cephalopods, squid and their allies, the cuttlefish and octopuses, are active hunters with long, dexterous arms radiating from a parrot-like beak, and advanced brains and nervous systems that enable the animals to detect prey, escape predation, mate and, it is thought by some scientists, communicate via colour change. Such active lifestyles among the cephalopods allowed for the evolution of advanced camera eyes, which contain an iris, lens and retina and are structurally similar to mammalian eyes.

As large as dinner plates, giant squid eyes are easily dislodged, which could also explain how the mystery eyeball was washed ashore. However, cephalopods belong to a much larger group of animals called the molluscs, which includes snails, slugs and clams. Whereas the lower representatives of this group are usually sedentary or slow-moving and often protected by robust shells, the higher cephalopods are free-swimming and almost entirely soft-bodied, except for the beak, which derives from the rasping radula found in snails, and the remnants of the protective shell now found within the body cavity, which forms a scaffolding framework (although octopuses lack this structure altogether). Yet the membranes surrounding the Floridian eye were also attached to bone fragments. Despite the large sizes of giant squid, they are invertebrates, and do not possess bony skeletons, which suggests the eye must originate from another animal group.

The scientists at the commission placed the eye on ice and sent it to the Fish and Wildlife Research Institute in St. Petersburg, Florida, where genetic testing would enable for classification. Due to the bone fragments, it is likely the organ belongs to a large pelagic fish, such as a tuna, marlin, or most likely a swordfish, although it could belong to a larger, deep water species. As a fast swimming predatory species in deeper ocean waters, swordfish have large eyes that are encased by robust eye sockets, which make it the most likely candidate. It is hoped that the results of the finding will be released soon. Questions concerning how the eye arrived on the shore are also being raised: The most likely scenario would involve a fisherman catching and gutting a swordfish on board and discarding the unwanted body parts overboard.

Discoveries from the Deep

The sighting of the eye and the widespread speculation it has sparked demonstrates an innate fascination that many people have for the sea. The find also reveals the lack of knowledge we have about the marine environment. Regularly, new species are being recorded and their behaviours observed for the first time. What is more, unexpected finds often make the media headlines. When a group of local fishermen hauled in a large and unusual fish off the coast of South Africa in 1938, biologists were shocked to note its anatomical similarities to fossil animals that were thought to have gone extinct during the Cretaceous period. This discovery of the primitive lobe-finned fish, known as a coelacanth, launched a quest for other specimens, and is often described as one of the great biological discoveries of the 20th century. More recently, yet less well-known, a strange circular structure was found on some water-logged wood off the coast of New Zealand in 1986. After observation, the life form was classified as an entirely new class of echinoderms (spiny-skinned animals that include starfish, sea urchins and sea cucumbers). Two years later in the Caribbean, another species of this class, now known as the Concentricycloidea, was also discovered.

Every time a deep sea submersible ventures to the ocean depths, new animals and even new ecosystems are found. Many sponges, jellyfish, molluscs, crustaceans and fish have been described from the abyss over the past decades. Yet probably the most astonishing find was in 1977, when a submersible discovered the first hydrothermal vents in the Galápagos Rift, along the East Pacific Rise. Unlike other environments, hydrothermal vents are ecosystems that thrive in conditions totally devoid of light. No plants can survive in the permanent darkness and so there is no photosynthesis to manufacture sugars. Rather, chemosynthetic bacteria derive energy by processing hydrogen sulphide and other sulphur-compounds released from hot, mineral-laden plumes that bellow from volcanic vents on the sea floor. The bacteria form the crux of an entire ecosystem, which includes worms, shrimps, crabs and fish.

A Lack of Understanding

These discoveries highlight the importance of not only preserving the oceans but also funding marine research. Little is known about many coastal regions, and almost nothing is known about the open oceans and their deep, inky depths. Not only is this research fascinating, as proven by the popularity of the Floridian eyeball mystery; the research also reveals more about the origins of marine organisms, and the potential medicinal properties some of these animals contain. It is known the some corals can help with bone grafting and tumour treatment and that horseshoe crab blood can help identify the presence of bacteria in medical samples. Just like the tropical rainforests are a living medical cabinet, the marine environment is also a pharmaceutical treasure-trove; and yet both environments are largely undiscovered and under threat. The popularity of the eyeball demonstrates a general intrigue in marine life; let’s hope this unusual find, along with other future discoveries strewn across the tideline, also invites marine research funding and protection.