Coelacanth

Thought to have been long extinct, scientists discovered these "living fossils" in 1938.

The primitive-looking coelacanth (pronounced SEEL-uh-kanth) was thought to have gone extinct with the dinosaurs 65 million years ago. But its discovery in 1938 by a South African museum curator on a local fishing trawler fascinated the world and ignited a debate about how this bizarre lobe-finned fish fits into the evolution of land animals.

There are only two known species of coelacanths: one that lives near the Comoros Islands off the east coast of Africa, and one found in the waters off Sulawesi, Indonesia. Many scientists believe that the unique characteristics of the coelacanth represent an early step in the evolution of fish to terrestrial four-legged animals like amphibians.

The most striking feature of this "living fossil" is its paired lobe fins that extend away from its body like legs and move in an alternating pattern, like a trotting horse. Other unique characteristics include a hinged joint in the skull which allows the fish to widen its mouth for large prey; an oil-filled tube, called a notochord, which serves as a backbone; thick scales common only to extinct fish, and an electrosensory rostral organ in its snout likely used to detect prey.

Coelacanths are elusive, deep-sea creatures, living in depths up to 2,300 feet (700 meters) below the surface. They can be huge, reaching 6.5 feet (2 meters) or more and weighing 198 pounds (90 kilograms). Scientists estimate they can live up to 60 years or more.

Their population numbers are, predictably, not well known, but studies in the Comoros suggest only about 1,000 remain there. They are considered an endangered species.

Fast Facts

Type:

Fish

Diet:

Carnivore

Average life span in the wild:

Up to 60 years

Size:

6.5 ft (2 m)

Weight:

198 lbs (90 kg)

Group name:

School

Protection status:

Endangered

Did you know?

A coelacanth's miniscule brain occupies only 1.5 percent of its cranial cavity; the rest is filled with fat.

Size relative to a 6-ft (2-m) man:

Anglerfish

Looking like something out of a science fiction movie, the anglerfish uses a natural lure to draw its next meal nearer.

The angry-looking deep sea anglerfish has a right to be cranky. It is quite possibly the ugliest animal on the planet, and it lives in what is easily Earth's most inhospitable habitat: the lonely, lightless bottom of the sea.

There are more than 200 species of anglerfish, most of which live in the murky depths of the Atlantic and Antarctic oceans, up to a mile below the surface, although some live in shallow, tropical environments. Generally dark gray to dark brown in color, they have huge heads and enormous crescent-shaped mouths filled with sharp, translucent teeth. Some angler fish can be quite large, reaching 3.3 feet (1 meter) in length. Most however are significantly smaller, often less than a foot.

Their most distinctive feature, worn only by females, is a piece of dorsal spine that protrudes above their mouths like a fishing pole—hence their name. Tipped with a lure of luminous flesh this built-in rod baits prey close enough to be snatched. Their mouths are so big and their bodies so pliable, they can actually swallow prey up to twice their own size.

The male, which is significantly smaller than the female, has no need for such an adaptation. In lieu of continually seeking the vast abyss for a female, it has evolved into a permanent parasitic mate. When a young, free-swimming male angler encounters a female, he latches onto her with his sharp teeth. Over time, the male physically fuses with the female, connecting to her skin and bloodstream and losing his eyes and all his internal organs except the testes. A female will carry six or more males on her body.

Fast Facts

Type:

Fish

Diet:

Carnivore

Size:

8 in (20 cm) up to 3.3 ft (1 m)

Weight:

Up to 110 lbs (50 kg)

Group name:

School

Did you know?

The anglerfish's lighted lure glows with the help of millions of bioluminescent bacteria.

Size relative to a tea cup:

Sockeye Salmon

Sockeye salmon are known for their bright red skin, but are actually blue while in the ocean. Only when they return to freshwater to spawn do they turn red.

The name sockeye comes from a poor attempt to translate the wordsuk-kegh from British Columbia's native Coast Salish language. Suk-kegh means red fish.

The sockeye, also called red or blueback salmon, is among the smaller of the seven Pacific salmon species, but their succulent, bright-orange meat is prized above all others. They range in size from 24 to 33 inches (60 to 84 centimeters) in length and weigh between 5 and 15 pounds (2.3 to 7 kilograms).

Like all other Pacific salmon, they are born in fresh water. However, sockeye require a lake nearby to rear in. Once hatched, juvenile sockeyes will stay in their natal habitat for up to three years, more than any other salmon. They then journey out to sea, where they grow rapidly, feeding mainly on zooplankton. They stay in the ocean for one to four years.

Sea-going sockeyes have silver flanks with black speckles and a bluish top, giving them their "blueback" name. However, as they return upriver to their spawning grounds, their bodies turn bright red and their heads take on a greenish color. Breeding-age males have a distinctive look, developing a humped back and hooked jaws filled with tiny, easily visible teeth. Males and females both die within a few weeks after spawning.

Sockeyes are the third most abundant of the species of Pacific salmons and are a keystone in the North American commercial fisheries.

Fast Facts

Type:

Fish

Diet:

Omnivore

Average life span in the wild:

3 to 5 years

Size:

Up to 33 in (84 cm)

Weight:

5 to 15 lbs (2.3 to 7 kg)

Group name:

Bind or run

Did you know?

Sockeye salmon meat gets its color from the orange krill they eat while in the ocean.

Size relative to a 6-ft (2-m) man:

Leafy and Weedy Sea Dragon

Leafy sea dragons are brown to yellow in body color and are more ornately adorned than the reddish colored weedies.

Sea dragons are some of the most ornately camouflaged creatures on the planet. Adorned with gossamer, leaf-shaped appendages over their entire bodies, they are perfectly outfitted to blend in with the seaweed and kelp formations they live amongst.

Endemic to the waters off south and east Australia, leafy and weedy sea dragons are closely related to seahorses and pipefish. Leafies are generally brown to yellow in body color with spectacular olive-tinted appendages. Weedies have less flamboyant projections and are usually reddish in color with yellow spots.

Sea dragons have very long, thin snouts; slender trunks covered in bony rings; and thin tails which, unlike their seahorse cousins, cannot be used for gripping. They have small, transparent dorsal and pectoral fins that propel and steer them awkwardly through the water, but they seem quite content to tumble and drift in the current like seaweed. Leafies grow to a length of about 14 inches (35 centimeters), while the slightly larger weedies can grow up to 18 inches (46 centimeters) long.

As with sea horses, sea dragon males are responsible for childbearing. But instead of a pouch, like sea horses have, male sea dragons have a spongy brood patch on the underside of the tail where females deposit their bright-pink eggs during mating. The eggs are fertilized during the transfer from the female to the male. The males incubate the eggs and carry them to term, releasing miniature sea dragons into the water after about four to six weeks.

Sea dragons survive on tiny crustaceans such as mysids, or sea lice. It is not known if they are preyed upon by other animals. They are, however, frequently taken by divers seeking to keep them as pets. In fact, such takings shrank their numbers so critically by the early 1990s that the Australian government placed a complete protection on both species. Pollution and habitat loss have also hurt their numbers, and they are currently listed as near threatened.

Fast Facts

Type:

Fish

Diet:

Carnivore

Size:

Leafy, up to 13.8 in (35 cm), Weedy, up to 18 in (46 cm)

Did you know?

The tail of a male leafy sea dragon will turn bright yellow when he is ready to mate.

Size relative to a tea cup:

Sailfish

The fastest fish in the ocean, sailfish can reach speeds of 68 miles (110 kilometers) per hour. Their large size and spirited fight make them a favorite among trophy fishers.

The two main subspecies of sailfish, Atlantic and Indo-Pacific, range throughout the warm and temperate parts of the world’s oceans. They are blue to gray in color with white underbellies. They get their name from their spectacular dorsal fin that stretches nearly the length of their body and is much higher than their bodies are thick.

They are members of the billfish family, and as such, have an upper jaw that juts out well beyond their lower jaw and forms a distinctive spear. They are found near the ocean surface usually far from land feeding on schools of smaller fish like sardines and anchovies, which they often shepherd with their sails, making them easy prey. They also feast on squid and octopus.

Their meat is fairly tough and not widely eaten, but they are prized as game fish. These powerful, streamlined beasts can grow to more than 10 feet (3 meters) and weigh up to 220 pounds (100 kilograms). When hooked, they will fight vigorously, leaping and diving repeatedly, and sometimes taking hours to land.

Sailfish are fairly abundant throughout their range, and their population is considered stable. They are under no special status or protections.

Fast Facts

Type:

Fish

Diet:

Carnivore

Average life span in the wild:

4 years

Size:

5.7 to 11 ft (1.7 to 3.4 m)

Weight:

120 to 220 lbs (54.4 to 100 kg)

Group name:

School

Did you know?

Sailfish are the fastest fish in the ocean and have been clocked leaping out of the water at more than 68 mi (110 km) per hour.

Size relative to a 6-ft (2-m) man:

Flying Fish

A streamlined torpedo shape helps flying fish generate enough speed to break the water’s surface, and large, wing-like pectoral fins help get them airborne.

Flying fish can be seen jumping out of warm ocean waters worldwide. Their streamlined torpedo shape helps them gather enough underwater speed to break the surface, and their large, wing-like pectoral fins get them airborne.

Flying fish are thought to have evolved this remarkable gliding ability to escape predators, of which they have many. Their pursuers include mackerel, tuna, swordfish, marlin, and other larger fish. For their sustenance, flying fish feed on a variety of foods, including plankton.

There are about 40 known species of flying fish. Beyond their useful pectoral fins, all have unevenly forked tails, with the lower lobe longer than the upper lobe. Many species have enlarged pelvic fins as well and are known as four-winged flying fish.

The process of taking flight, or gliding, begins by gaining great velocity underwater, about 37 miles (60 kilometers) per hour. Angling upward, the four-winged flying fish breaks the surface and begins to taxi by rapidly beating its tail while it is still beneath the surface. It then takes to the air, sometimes reaching heights over 4 feet (1.2 meters) and gliding long distances, up to 655 feet (200 meters). Once it nears the surface again, it can flap its tail and taxi without fully returning to the water. Capable of continuing its flight in such a manner, flying fish have been recorded stretching out their flights with consecutive glides spanning distances up to 1,312 feet (400 meters).

Flying fish are attracted to light, like a number of sea creatures, and fishermen take advantage of this with substantial results. Canoes, filled with enough water to sustain fish, but not enough to allow them to propel themselves out, are affixed with a luring light at night to capture flying fish by the dozens. There is currently no protection status on these animals.

Fast Facts

Type:

Fish

Diet:

Omnivore

Size:

Up to 18 in (45 cm)

Group name:

School

Did you know?

Flying fish can soar high enough that sailors often find them on the decks of their ships.

Size relative to a tea cup:

Boa Constrictor

As their name suggests, boa constrictors slowly squeeze their prey to death.

Boa constrictors wear some of the most distinctive markings of all reptiles. Depending on the habitat they are trying to blend into, their bodies can be tan, green, red, or yellow, and display cryptic patterns of jagged lines, ovals, diamonds, and circles.

Boas are nonpoisonous constrictors found in tropical Central and South America. Like their anaconda cousins, they are excellent swimmers, but prefer to stay on dry land, living primarily in hollow logs and abandoned mammal burrows.

Significantly smaller than anacondas, boas can grow up to 13 feet (4 meters) long and weigh more than 100 pounds (45 kilograms). Their jaws are lined with small, hooked teeth for grabbing and holding prey while they wrap their muscular bodies around their victim, squeezing until it suffocates. Boas will eat almost anything they can catch, including birds, monkeys, and wild pigs. Their jaws can stretch wide to swallow large prey whole.

Female boas incubate eggs inside their bodies and give birth up to 60 live babies. Boas are about 2 feet (0.6 meters) long when they are born and grow continually throughout their 25 to 30-year lifespan. The largest boa constrictor ever found measured 18 feet (5.5 meters).

Hunted for their fine, ornate skin and for sale in the exotic pet trade, some boa constrictors are endangered and most have protected status in their range.

Fast Facts

Type:

Reptile

Diet:

Carnivore

Average life span in the wild:

20 to 30 years

Size:

13 ft (4 m)

Weight:

60 lbs (27 kg)

Group name:

Bed or knot

Did you know?

Some South Americans keep boas in their houses to control rat infestations.

Size relative to a 6-ft (2-m) man:

Eastern Coral Snake

While no eastern coral snake-related deaths have been reported since the late 1960s, untreated bites can lead to cardiac arrest.

A bite from the notoriously venomous eastern coral snake at first seems anticlimactic. There is little or no pain or swelling at the site of the bite, and other symptoms can be delayed for 12 hours. However, if untreated by antivenin, the neurotoxin begins to disrupt the connections between the brain and the muscles, causing slurred speech, double vision, and muscular paralysis, eventually ending in respiratory or cardiac failure.

This iconic snake, with its bulbous head and red, yellow, and black bands, is famous as much for its potent venom as for the many rhymes—"Red and yellow, kill a fellow; red and black, friend of Jack"—penned to distinguish it from similarly patterned, nonvenomous copycats, such as the scarlet king snake.

Coral snakes are extremely reclusive and generally bite humans only when handled or stepped on. They must literally chew on their victim to inject their venom fully, so most bites to humans don't result in death. In fact, no deaths from coral snake bites have been reported in the U.S. since an antivenin was released in 1967.

Eastern coral snakes are relatives of the cobra, mamba, and sea snake. They live in the wooded, sandy, and marshy areas of the southeastern United States, and spend most of their lives burrowed underground or in leaf piles.

They eat lizards, frogs, and smaller snakes, including other coral snakes. Baby snakes emerge from their eggs 7 inches (17.8 centimeters) long and fully venomous. Adults reach about 2 feet (0.6 meters) in length. Average lifespan in the wild is unknown, but they can live up to seven years in captivity.

Fast Facts

Type:

Reptile

Diet:

Carnivore

Average life span in captivity:

Up to 7 years

Size:

20 to 30 in (51 to 76 cm)

Group name:

Bed or knot

Did you know?

When threatened, a coral snake will curl the tip of its tail to confuse its attacker as to which end is its head.

Size relative to a 6-ft (2-m) man: