The Pufferfish is also known as the blowfish, fugu, swellfish, and globefish. It is called the pufferfish because when it is threatened, it puffs up to about twice its normal size by gulping water. In this engorged state, the pufferfish can swim at only about half its normal speed.
There are about 100 species of pufferfish. Most pufferfish are found in sub-tropical and tropical marine waters (including coral reefs) in the Atlantic, Pacific, and Indian Oceans. Some puffers live in brackish and fresh water.
Poison: Many parts of the blowfish (including the liver, muscles, skin, and ovaries) contain an extremely strong, paralyzing poison called tetrodoxin. This poison is about a thousand times deadlier than cyanide. There is no known antidote for this poison. Fugu (torafugu or fugu rubripes, Japanese pufferfish) is eaten in Japan, but is only cooked by specially-trained chefs who can minimize the amount of poison. Even so, many Japanese diners have died from eating this poisonous delicacy.
Diet: Pufferfish are carnivores (meat-eaters). They eat corals, sponges, sea urchins, other echinoderms, and small crustaceans. Pufferfish crush and grind up their prey with their heavy, fused teeth.
Anatomy: Pufferfish have a small mouth, a tube-shaped body (when not engorged) and relatively small fins. When puffed up, they are almost spherical. Pufferfish range in size from just a few inches long to almost 2 feet long. A few species of pufferfish have spines on their body (modified scales), but many do not. The skin of puffers is very elastic (it can stretch very well).
The lanternfish is a common, deep-sea dweller that has many light-producing organs along its body, especially the belly. This fish lives in a dark environment, and its bio-luminescent organs light up as the lanternfish swims. It uses its lights to lure prey to it and to attract other fish.
Lanternfish live in mid-ocean depths (several hundred feet down) but swim to the surface at night. They are found in oceans all over the world. The different species of Lanternfish have different patterns of light and are different colors.
Anatomy: Lanternfish have huge eyes and a series of light-producing organs along their underside. The largest Lanternfish are rarely over 1 foot (30 cm) long. Myctophum affine (pictured on this page) is up to 5 inches (15 cm) long and has silver scales.
Diet: Lanternfish eat copepods (small invertebrates with big eyes and long antennae) and amphipods (like shrimp).
The Bluefin Tuna (Thunnus thynnus) is a large bony fish and is the largest tuna. The Bluefin Tuna lives for about 40 years.
The Southern Bluefin Tuna is a species very similar to and closely related to the Bluefin Tuna. These two fish only differ internally. The Southern Bluefin lives in the Southern Hemisphere from about 30° to 50° Latitude South. They breed in the Indian Ocean near Indonesia. The Southern Bluefin Tuna has been overfished and is in danger of extinction.
Anatomy: The Bluefin Tuna is dark blue to almost black above and light silver below. There is a yellow line from the snout along half of the body. This yellow line disappears after death. The tail is dark blue. It typically grows to be about 6 ft (2 m) long and weighs about 300 pounds (135 kg). The heaviest known are about 1,200 pounds (550 kg). The Bluefin Tuna is mature at about 8 years old, when it has reached a length of about 5 feet (1.5 m).
Diet: Bluefin Tuna eat fish, including mackerel.
There are about 100 species of moray eels worldwide. These fish live in coral reefs or rocky areas of shallow tropical seas worldwide. These nocturnal (most active at night) fish have a long, muscular, snake-like body.
Anatomy: Moray eels have skin that is scaleless, thick, camouflaged, and covered with protective mucus. The eyes are tiny, and this fish has very bad vision. Morays have a small, circular gill on each side of the head, well behind the mouth. The mouth is kept open (and moving) to help water circulate through the gills (even the inside of this eel's mouth is camouflaged since it is kept open). The wide jaws are filled with long, sharp teeth. Most morays lack pectoral and pelvic fins; the dorsal fin runs along most of the back to the caudal fin (the tail) and into the anal fin, which runs along the underside of the body. Moray eels average about 5 feet (1.5 m) long. The biggest moray is Thyrsoidea macrurus of the Pacific Ocean, which is up to about 3.5 m (11.5 feet) long.
Diet: Morays eat other fish (including other eels) and mollusks (like octopi). Camouflaged moray eels hide among rocks, coral, or eelgrass beds, waiting for prey animals to get near enough to catch them. Morays find prey mostly by using a keen sense of smell.
Enemies: Morays have few predators. Large groupers and other moray eels sometimes prey upon morays. Some morays are eaten by people (but some species are toxic to people).
Classification: Class Osteichthyes (bony fish), Subclass Actinopterygii (ray-finned fish), Order Anguilliformes (eels), Family Muraenidae (moray eels), many genera and species.