Logic will always sustain that big fish eat small fish. But what a fisherman from Grand Cayman has found could be a world record contradicting the 'rule'.

McPherson 'Dorson' Wright was fishing at about 1,400 feet (570 m) off the South Coast of Grand Cayman, when he observed an object floating on the sea surface. He approached to see what that was and what found a dead fish that left him and scientists open-mouthed: the fish had in its belly a much larger fish than itself. When the prey was measured, scientists found that the species was a 'snake mackerel' four times longer than its predator.

"When I first saw it I really couldn't believe my eyes. It had obviously just died, so I decided I had to put it in the boat and take it down to the Department of the Environment to investigate it further.", said Wright.

Marine Scientist Phillippe Bush took some photos which he sent to the Harbor Branch Oceanographic Institute in US. Tracey Sutton established that the predator was a Black Swallower (Chiasmodon niger), a fish that normally lives in waters below 750 m (2,300 ft) down to 2,745 m (8,250 ft). This fish, an abyssal species hard to study, is known to feed on whole fish, often longer than itself; still, this here is a record. "This is amazing! I have seen this fish with big prey before but yours takes the cake. It would surely rank as one of the largest, if not the largest, rations known among all fishes (relative to their own weight). The finding would be written up in a scientific paper," wrote Sutton.

The scientists are puzzled by how the Great Swallower not only ate the Snake Mackerel (Gempylus serpens), but managed to avoid becoming itself the meal of its prey. The Black Swallower was only 7.5 inches (19 cm) long (they do not bypass anyway 10 in (25 cm)), while its prey snake mackerel, a very aggressive predatory fish, measured 34 inches (85 cm)! (the species can reach a maximum of 100 cm (40 in). "I would hate to see what a three-foot-long Great Swallower is capable of eating.", Bush said.