Snakes vary in size, from the tiny size of the Barbados thread snake to the massive reticulated python. Sizes also vary within a species, and there can be several reasons why an individual member of a species experiences massive growth while others may not. In this article, we will examine the largest cottonmouth on record and try to answer the question: what are the reasons it grew so large?

About Cottonmouths
An extremely venomous pit viper, the cottonmouth (or water moccasin), will spend most of its life near water and is one of the world’s few semiaquatic snakes. Cottonmouths swim in both saltwater and freshwater. There are two species: the Florida cottonmouth and the northern cottonmouth.
Typically, larger cottonmouths reach about four feet long, but people have reported larger snakes. Adults have heavy bodies, appearing even larger when swimming because they carry their bodies on top of the water. The males of the species are heavier than the females and have more scales along the tail.
The head of a cottonmouth has a distinctive spade shape, and the mouth is white when opened. The body is a combination of black, olive, or brown in alternating light and dark bands. Young cottonmouths will have more defined alternating bands with a sometimes green or yellow tip on their tail.

The largest cottonmouth in the wild arere about 5-6 feet long.
©Kristian Bell/Shutterstock.com
The Largest Cottonmouth Ever Recorded
Large cottonmouths in the wild are recorded at between 60 and 74 inches. Five feet long is quite large for a cottonmouth, though this length has been recorded before.
The largest recorded length for a cottonmouth is 74 inches. This specimen lived in the Dismal Swamp on the Virginia and North Carolina border. There have been reports of cottonmouths reaching lengths of 8-9 feet, but those are unconfirmed. No matter the size, cottonmouths are dangerous.

One of the reasons that cottonmouths can grow so large is that they have indeterminate growth.
©Kyle J Little/Shutterstock.com
The Largest Cottonmouth: 3 Reasons It Grew So Large
Three of the factors that will impact a cottonmouth’s size are its longevity, its genetic makeup, and the consistent availability of food.
Longevity
Snakes have “indeterminate growth.” This means that they never truly stop growing. The older a cottonmouth gets, the larger it gets. This means that its size depends on its ability to survive, which has to do with its environment, genetic strength, disease, diet, and exposure to predation. The largest cottonmouth on record would have been an extremely long-lived snake.
Genetics
Even though it has the advantage of indeterminate growth, much of a cottonmouth’s growth occurs before it reaches maturity, when it grows more slowly. At this point, it directs energy toward reproduction and survival, taking energy away from growth. Growth during its early years will account for most of its size, and genetics will play a large part in this. This massive cottonmouth was genetically programmed to grow so large.
Food Availability
Snakes will redirect energy away from growth towards survival when food is scarce. On the other hand, when food is abundant, snakes will experience rapid growth during their early years, and cottonmouths are no exception. During this cottonmouth’s early years, prey such as mice, fish, shrews, frogs, birds, insects, and eggs were probably readily available.

Snapping turtles
are predators of juvenile cottonmouths.
©Tyler Clemons/Shutterstock.com
Conclusion
While cottonmouths can reach impressive lengths of 4-5 feet, sometimes the conditions are suitable for a specimen to achieve impressive lengths of six feet or more. The largest cottonmouth on record responded to the factors of longevity, strong genetics, and abundant food availability to become a massive 74-inch record-breaker.
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