Marsh fishermen share waters with a beautiful little creature that is usually out of sight out of mind unless one pops its head up next to their boat.

The diamondback terrapin is a turtle largely ignored today, but a hundred years ago soups and stews made with its flesh were insanely popular, especially on the east coast from Baltimore to New York.

They are odd little creatures: It’s the only turtle or terrapin in the world that lives in brackish water marshes.

Seven turtle species have evolved to live in the sea. All are large, and all are equipped with flippers instead of clawed feet.

All the hundreds of other species live in freshwater or on land.

The diamondback terrapin — scientifically known as Malaclemys terrapin — is more closely related to box turtles and freshwater turtles such as the red-eared slider turtle (streaky-head or mobilian) than it is to sea turtles, even though it spends almost its entire life in the water. 

“Malaclemys” is derived from Greek and roughly translates as “soft tortoise,” apparently in reference to its hinged plastron (lower shell). The word terrapin comes from the New Latin word “terrapin” meaning “tortoise.”

Their common name comes from the diamond shapes of the scales (called scutes) that make up their carapaces or top shells.

No two terrapins are colored exactly alike. Some are almost yellow, others are green, gray, brown or black. Some are brightly colored, and some are drab.

The one thing they all have in common are wiggly black marks or dots on the skin of their heads and legs.

For eons, diamondback terrapins puttered around in marsh habitats, happily crunching on snails, clams and mussels, crabs, marine worms and fish.

Bigger turtles — sea turtles, snapping turtles, alligator snapping turtles and giant land tortoises — had long been recognized as being excellent table fare.

Then the Gilded Age, the age of conspicuous consumption, descended on America in the 1870s.

The country had a surplus of newly minted millionaires centered in the eastern capitalist establishment. They had money and were willing to spend it on mansions, fancy balls, European art collections and extravagant dinners to show that they had it.

French chefs became the vogue, and the influence of French cuisine transformed humble American turtle stew to Terrapin Stew à la Maryland, and the little diamondback terrapin was declared the best turtle of all to cook.

The great French chef Auguste Escoffier declared the diamondback terrapin to be “king of all turtles.”

The little reptile had arrived, almost to the misfortune of the species.

Voracious demand gobbled up the central Atlantic supply, and terrapin purveyors turned to the South for more. Louisiana, with its vast marshes, had a mother lode of diamondbacks.

Grand Isle seemed to be a center for Louisiana turtling, and at its heart was John Ludwig, known as “King John” or the “Terrapin King.” Truly the Donald Trump of Grand Isle of his day, Ludwig was a merchant who developed the island’s massive cucumber farming industry.

He also bought and sold diamondback terrapins.

Terrapins could be netted and dogs could be used to hunt the females when they came on land to dig their nests and lay their eggs in May, June and July.

But most were caught in simple but ingenuous traps.

Trappers would build fences or walls of planks laid on edge in the marsh. At the end of the fence, they would sink barrels level with the marsh surface. Any female terrapin (aka cows) that hit the fence would follow it to the end and fall into the barrel.

Catches of 25 turtles in one barrel were not rare.

Around 1900, Ludwig began farming them. Ever shrewd, he didn’t feed the young turtles to grow them out because it took four years for them to reach maturity, plus bulls (males) were worth very little. Rather, he kept the breeding adults in pens with slats set far enough apart to allow the hatchlings to escape into the marsh and feed themselves.

One advantage in penning the adults was that the nests were protected from predators. In the wild, only 1 to 3 percent of the eggs successfully hatch. Raccoons, mink, skunks and rats get the rest before they hatch.

Ludwig simply paid trappers to bring the turtles back to him when they were big enough to sell five years later.

On the East Coast, the largest females — those over 8 inches plastron (bottom shell) length — went for $96 to $125 a dozen. Smaller females brought less, but even “half-counts” (females between 5 and 6 inches long) brought $20 to $25 per dozen.

In contrast, bull terrapin sold for $4 to $10 a dozen. A working man’s wages at the time were $1 to $1.50 a day.

As any fad has to, the terrapin market disintegrated. Many writers conveniently but incorrectly blame Prohibition for the collapse, citing the fact that sherry was often an ingredient in turtle soup — and without sherry, no one wanted the soup. 

Giving lie to that claim is the fact that Ludwig shipped 60,000 terrapins out of Grand Isle in 1932, the second to last year of Prohibition.

More than likely, the end of the terrapin trade was that the fad ran its course, the onset of the Great Depression and an overall decline in terrapin availability.

In Louisiana, a prohibition on the use of traps to catch the animal led to the industry’s decline.

Diamondback populations from Massachusetts to Texas have long recovered from overharvesting wherever their habitat hasn’t been destroyed.

In most places shore development has been an issue. In Louisiana the major problem is coastal erosion. 

Diamondbacks are well adapted to their saline environment. Although they drink fresh rainwater that layers on the surface of saline marsh water during rainstorms, they also possess lachrymal glands near each eye that excrete excess salt from their bodies.

During the winter, they bury themselves in water-bottom mud. Their oxygen needs are greatly reduced because of their cold-slowed metabolism and their inactivity while dormant. Any oxygen needed is absorbed through their mouths and, believe it or not, through their cloaca (aka anus). 

In captivity, diamondback terrapins live very well in pure freshwater, but they are never found there in the wild, probably due to competition from the many turtle species living in freshwater. Captive diamondbacks have been recorded to live 40 years.

Males only grow to half the size of females: 5½ inches maximum plastron length compared to 11 inches for females. A female can store sperm from one mating for several years and can also lay eggs fertilized with the sperm of different males in the same clutch.

Females dig nest cavities on land 4 to 8 inches deep, in which she lays four to 20 eggs. She covers the eggs before leaving the nest. Females lay three clutches per summer, and the eggs hatch in August and September.

Interestingly, nest temperatures determine the gender of the hatchlings. Higher temperatures produce more females, while lower temperatures produce more males. Hatchlings might stay on land all their first winter and are more freeze-tolerant than are adult terrapins.

For what it’s worth, diamondback turtles may still be harvested in Louisiana, although not with traps of any kind. All terrapins taken must be at least 6 inches plastron length, and the season is closed from April 15 to June 15 of each year.