The ocean is a combination of exotic beauty, baffling mysteries, and endless variety. And while its inhabitants are wondrous to behold, you’ll want to keep your distance from these undersea brutes:
Look but don't touch. A popular saltwater aquarium fish, the lionfish has distinctive maroon (or brown) and white stripes, fleshy tentacles above the eyes and below the mouth, and an imposing fan of prickly venomous spines.
Although not fatal to humans, the dorsal, anal, and pelvic spines of lionfish can deliver a painful sting that can cause headaches, vomiting, and respiratory distress. The worst of the pain lasts only for about an hour, but some people report pain and tingling sensations around the wound for several days or weeks.
Because these fish are not aggressive toward people, contact is usually accidental. Home aquarium owners are more likely to be stung by lionfish than divers or fishermen, but the latter could be placed at higher risk if lionfish continue to increase in large numbers along the heavily populated East Coast.
Lionfish are harmful to the ecosystems they inhabit because they have few, if any, natural predators. They feed on practically anything that swims and can easily devour the young of important commercial fish species, such as snapper, grouper and sea bass. [Watch Invasion Lionfish video]
High resolution (Credit: Rosenstiel School of Marine & Atmospheric Science)
The tiger shark is one of the larger shark species — the smallest adults measure about 9 feet, while the largest are known to exceed 18 feet and 2,000 lbs. It has a large head, blunt snout, wide mouth, and curved, heavily serrated teeth with distinct notches on their outer edges.
Small tiger sharks are easily distinguished by their coloration, which varies from bluish to greenish gray to black on its back and from light gray to dirty yellow or white on its underbelly. Juveniles have black spots, which fuse together to create vertical bars resembling tiger stripes as the shark ages. In large tiger sharks, the bars tend to fade, but are usually visible upon close inspection.
The tiger shark is a true predator and will eat just about anything. Referred to as the "the wastebasket of the sea," the tiger shark’s diet includes fish, seals, birds, squid, small sharks, and dolphins — even man-made trash such as license plates or pieces of old tires.
Although shark attacks on humans are pretty rare, the tiger shark is responsible for most of those that prove fatal. Second only to the great white shark in the number of recorded attacks, the tiger shark is regarded as one of the most dangerous of the species. In Hawaii, it’s the only shark that comes inshore and attacks surfers and swimmers.
The tiger shark is found in many of the tropical and temperate regions of the world's oceans, and is especially common around islands in the central Pacific.
Moray eels — fish with a snakelike body, protruding snout and wide jaws — lack the side fins and scales of common eels, but have very well-developed teeth. There are many species of moray eels, which come in a wide variety of beautiful patterns such as speckles, freckles, or stripes in a variety of colors like chocolate brown, off-white, black, sandy yellow, scarlet and blue.
Scary looking, these fish can reach 6 to 8 feet in length. A bite from their razor-sharp teeth and powerful, locking jaws will produce ragged wounds that are prone to infection from the bacteria inside the eels’ mouths. If morays bite out of fear or by accident (especially when foraging for food), they will usually release their grip and let you go.
Moray eels live in all tropical and subtropical seas and spend most of their day in holes and crevices — they prefer to hunt for food at night. As predators, morays are opportunistic omnivores who try to eat most any fish and/or invertebrate slow enough for them to grab. Morays cannot see or hear very well and rely mostly on their acute sense of smell to guide them to their prey.
To prevent contact and possible severe injury, keep your hands out of submerged, rocky holes and crevices. If you must, use a stick to gently probe an area of interest.
Moray eels aren’t usually aggressive toward divers and snorkelers. But, they can be territorial or become aggressive, especially in the presence of speared fish.
To learn more about these and other undersea creatures, visit NOAA’s National Marine Fisheries Service Web site.