But for a truly unique maritime experience, join me on a Sea Serpent Day (August 6th or 7th; there is some dispute) excursion to LISTVILLE (population: five).

The first mention of sea serpents in letters is generally accepted as coming from Virgil’s Aeneid, around 30 BCE. Laocoön, priest of Neptune, was preparing a bull sacrifice with his sons when “a pair of sea serpents with huge coils” and “blood-red crests” made way for the shore and enveloped the statue-ready trio in their “scaly folds.” There were “burning eyes” and “hissing jaws,” and I’m told younger and more sensitive altar viewers needed to leave the room.

Oarfish engraving, c. 1889 (Florida Center for Instructional Technology)

In the centuries since, ‘sea serpents’ and their sundry variations have been reported everywhere from Nova Scotia to the Portuguese coast and described variously as “turtle-like,” cow-faced and possessed of “brilliant flaming eyes” (these and other details come mostly from Richard Ellis’s 1994 book ‘Monsters of the Sea,’ which contains many period eyewitness accounts full of taxonomic and linguistic weirdness).

While we’ve yet to get reliable word of the existence of sea serpents, scientists have come up with a number of likely—and in some cases verified—explanations for sea serpent sightings, including these five based on actual, factual wildlife.

1) Oarfish

Long-dead and therefore significantly less serpent-ish oarfish (flickr | muzina_shanghai)

This is one of the simplest imaginable explanations, and the first thing I thought of when I read about the “blood-red crests” of the Laocoön-eating serpents (Scientists too. See incredible photos on this blog and the engraving above; sea-serpent-ish, no?).

Now, Oarfish are an unassuming family of bony saltwater fish, only slightly more likely to fatally maul a hirsute Trojan priest than a clump of kelp. Still, the largest of them, the King of Herrings, may reach somewhere between 40 and 50 feet in length, and could easily set the imagination racing as it breaks the surface of the water crest-first, its big eyes glistening.

The oarfish is scarce, apparently tastes bad and is still largely a mysterious animal. Here’s Kurt Ove Eriksson, who spotted a smaller specimen off of Sweden’s western coast last year: “At first we thought it was a big piece of plastic. But then we saw an eye [...] I went down to check and saw that it was this extremely strange fish.” Nice work, Kurt.

2) Basking Shark

A non-decomposing basking shark. (flickr | Green Massachusetts)

In one of the most famous sea serpent incidents of recent times, a Japanese fishing boat near New Zealand hauled in a vaguely monsterish corpse in 1977. It appeared to be a long-necked, small-headed, four-flippered creature—a surviving plesiosaur, perhaps, long the single most popular sea serpent theory. Crewmembers discarded the corpse, but not before numerous intensely-scrutinized photos and samples were collected.

The corpse remains popular in cryptozoological lore despite the near-unanimous informed conclusion  that it was, in fact, a partially-decayed basking shark. The placid filter-feeder is well known for rotting into a what appears to be a serpentine form. From the link above, originally printed in Reports of the National Center for Science Education: “When the basking shark decays, the jaws and loosely attached gill arches often fall away first, leaving the appearance of a long neck and small head [...] All or part of the tail (especially the lower half which lacks vertebral support) and/or the dorsal fin may also slough away before the better supported pectoral and pelvic fins, creating a form that superficially resembles a plesiosaur.” More:

Interestingly, basking sharks seem to have a propensity to mimic sea serpents while alive as well as dead. Often they feed in groups at or near the surface (hence their name), sometimes lining up two or more in a row. When they do this, the dorsal and tail fins protruding from the water can be, and sometimes have been, mistaken for multiple “humps” and head of a long-bodied sea-monster (Sweeney 1972; Bright 1989; Ellis 1989; Perrine 1995).

3) Basilosaurus/Zeuglodon (prehistoric whale)

I’m cheating here, but the badly-named basilosaurus (originally thought to be a type of dinosaur) WAS a real, live animal at one point.

You have to admit, it was a nice try. (Wikimedia commons)

In 1845, a German entrepreneur/collector/flim-flammist named Albert Koch unveiled a crazy looking skeleton—a modern-day sea serpent, he said—and toured with it in New York and other American cities. For a little while, it was the talk of zoology, taken by casual observers as proof that sea monsters existed (Koch claimed to have unearthed the skeleton in Clarksville, Alabama, and went so far as to describe its behavior and other details on the basis of the bones).

Despite the unending credulity of contemporary audiences—this kind of hoax was perpetrated often and successfully in 19th-century science, which was sometimes closer to circus exhibitionism than anything else—it became clear pretty quickly that the 114-foot thing had been cobbled together from a variety of bones taken from five or so specimens of the the long-extinct basilosaurus, a prehistoric cetacean (certainly not a reptile, as Koch claimed).

Koch’s scientific name for the creature–-hydrarchos sillimani—was derived from the naturalist Dr. Benjamin Silliman, whose presence was thought to lend scientific legitimacy to the affair. Once Harvard anatomist Jeffries Wyman and others pointed out that it was an obvious fraud, Silliman requested his name be removed (Though, hey, it’s the main reason people remember him. There’s a lesson there).

4) Giant Squid

Giant squids are already among the coolest, monsteriest creatures of the deep, but they may account for some of the earliest serpent sightings as well.

(Wikimedia commons)

In the mid-18^th century, Bishop Pontoppidan reported a “Sea-monster” that “looks at first like a number of small islands, surrounded with something that floats and fluctuates like sea weeds” (see image at right, also featured in Ellis’s book). The Pontoppidan sighting was widely agreed to be a giant squid later on.

Later, in 1849, Prof. Japetus Steenstrup determined that a carcass discovered in 1639 (“a peculiar creature or sea monster” with “7 tails” covered in “buttons” and a soft body without bone or cartilage), presumed to be a serpent of some kind, was actually Architeuthis (with a few body parts missing). Many other sightings and discovered bodies from the 16^th-18^th centuries seem to fit this description as well.

Luckily, once people started figuring out that these multi-tailed (or headed) serpents were actually cephalopods, they were able to shift pretty seamlessly to freaking out about impossibly huge tentacled ‘krakens.’

5) Elephant Seal

This is cute, but admit it--it's also really weird-looking. (flickr | Jim Bahn)

Sir Richard Owen (somewhat controversial himself as a contemporary and opponent of Charles Darwin, but an important scientist of the day nonetheless) famously suggested that the Daedalus sea serpent off the Cape of Good Hope in 1848 had in fact been a semiaquatic mammal.

According to Owen: “It is very probable that no one on board the Daedalus ever before beheld a gigantic seal swimming freely in the open ocean.”

It’s not hard to see how a large elephant seal, with its formidable length and swollen ‘trunk,’ could easily have accounted for a crypto-animal sighting when beheld by weary sailors. In fact, the ninth volume of the Museum of Foreign Literature and Science, published in 1826, mentions reports of a “sea-monster in the neighborhood of Behring’s Straits (sic)” with a “head resembling a sea-lion” dating to 1808.

More useful: modern paleozoologist Darren Naish and his colleagues Michael Woodley and Hugh Shanahan have suggested that many historical sea monster sightings might be explained by unknown or little-seen pinnipeds (see posts on this and related topics at the sadly defunct Tetrapod Zoology blog here and here).

The Fastest Swimmers

The sailfish is considered the fastest swimmer among fish, often reaching 70 mph. Although a black marlin was recently clocked at 80 mph so the sailfish record may fall to its cousin.

The fastest swimming mammal is the orca (often called killer whale) which can swim over 55 mph but the Dall’s porpoise of the north Pacific has been clocked at the same speed.

We all know that birds can fly fast.  In flight, the fastest bird is the spine-tailed swift of Siberia which can reach speeds in excess of 100 miles per hour, but the fastest bird in the water is the Gentoo penguin, which swims at about 22 mph. (Watch this video of a Gentoo swimming madly to avoid a pod of hungry orcas.)

The Gentoo’s speed is about the same as the fastest sea turtle, the leatherback.

Using a different mode of movement, squid can achieve 25 mph through a form of jet propulsion.

The Deepest Swimmers

Scientists once thought that the deepest parts of the ocean were too dark and cold to sustain life.  But they have been discovering that the deep ocean holds a rich ecosystem of many living forms.

For example, they have recently found a type of snailfish that lives happily nearly five miles down where the water pressure is almost unimaginable. (Watch this video of these true denizens of the deep.)

People are also often amazed to learn that whales once lived on land and liked swimming so much that they went back to living in the sea.  These sea-going mammals can dive down to some of the deepest parts of the ocean.  The sperm whale routinely dives to depths of 10,000 feet (about two miles) to hunt for giant squid.

Slowest Swimmer

Scientists believe that the sea horse is the slowest fish in the ocean.  It moves along at about 0.01 (one hundredth) mph.  (Watch this video shows how the sea horse swims.)

Largest Swimmers:

The whale shark is the largest fish in the sea.  One was measured at 41 feet in length and weighed over 35 tons. This (Watch this video of divers swimming near a whale shark.) However, the blue whale (a mammal) is the largest living creature.  Adult blue whales can reach 100 feet in length and 200 tons in weight.

The largest giant squid ever recorded was captured in the North Atlantic in 1878. It weighed 4 tons and its tentacles measured 10 m (35 ft) long.

The heaviest crustacean ever found swimming along the bottom was a lobster weighing 42 lbs, caught in 1934.

Secret Swimmers

Some animals have reputations for not being able to swim or being afraid of the water.  Take cats, for example.  The truth is cats can swim. Some cats, such as the jaguar of South and Central America are excellent swimmers.  Tigers are good swimmers too as it turns out.

With primates, most indications are that gorillas do not swim but that chimpanzees are swimmers, if reluctantly.

Other animals that are identified as not being able to swim range from camels to armadillos (although the long-nosed armadillo of South America is an armadillo species that can swim).

Unconventional Swimmers

Some fish swim vertically.  The sea horse is one example but there are many others in the fish world including the razor fish or shrimp fish, that swim a vertical position.

Many fish can swim backwards.  Eels are best known for this.

Anadromous species, such as salmon and shad, live in the ocean and travel up rivers to spawn.  These fish know to return to the same place from which they hatched.

Just Plain Different

Once in a while, something unexpected will happen.  Forget about the Loch Ness monster.  One time, in 2007, a deer was sighted miles from the shore in the Chesapeake Bay.  The fisherman who saw the deer took her on board his boat and released her safely on shore.

Another animal that is simply fascinating to watch in the water is the elephant.  (This video shows elephants swimming in deep water from an underwater perspective.)

Polar bears are also champion swimmers.  Recently, however, a lack of ice in the Arctic Ocean forced a particular polar bear to have to swim 426 miles over nine straight days to reach an ice flow.  The bear lost 100 pounds and a cub, and reminds us, during National Wildlife Week, of how important it is to protect natural environments worldwide – especially those of champion swimmers.

San Diego News report:

“Dozens of dazed Humboldt squid, which were roughly three- to four-feet long and weighed close to 40 pounds, were found flapping around on La Jolla Shores beach. “It’s like their equilibrium is all messed up and they don’t know what they’re doing and they can’t back out there,” said beachgoer Bill Baumann. “It was like they got … all shook up.”’ See full article.