Meet World’s largest snake, Ana Julia: 20.7-foot anaconda found in Amazon reshaping evolutionary understanding

How Ana Julia Became the World’s Biggest Known Green Anaconda (Representational Image: Canva)

A National Geographic expedition in 2024 confirmed the largest known green anaconda, Ana Julia, in Ecuador’s Amazon, reshaping understanding of snake size, evolution, habitat range, hunting behaviour, and conservation challenges facing the species today.

Did our AI summary help?

Scientists are reassessing anaconda size records after a National Geographic expedition confirmed the largest known green anaconda in the northern Amazon, offering new insight into evolution, habitat range, and survival strategies of the world’s heaviest snake species.

Anacondas rank among Earth’s most feared reptiles today. They are admired for size, strength, and patience. The green anaconda draws particular global scientific focus. It is recognised as the heaviest snake species. Females grow significantly larger than male counterparts. This size difference improves breeding success significantly. Scientists have long debated the species’ maximum size. Recent field evidence has now clarified uncertainties.

Record-holding green anaconda discovery

In 2024, National Geographic led extensive Amazon research. The team confirmed an enormous green anaconda specimen. The snake was named Ana Julia by researchers. It measured 20.7 feet in verified length. The specimen weighed approximately 441 pounds in total. The discovery occurred within Ecuador’s northern Amazon region.

Genetic analysis revealed a separate northern anaconda lineage. Scientists classified it as Eunectes akayima. This challenged earlier assumptions about green anaconda evolution. Researchers believe larger specimens may remain undocumented nearby. Indigenous Waorani communities report sightings of massive snakes. Vast Amazon waterways limit complete scientific surveying.

A team of scientists has discovered a new species of green anaconda in the Amazon rain forest.

Prof. Freek Vonk has recorded a video of a 26-feet-long green anaconda, believed to be the biggest snake in the world.pic.twitter.com/mZyF7nX3a6 — Massimo (@Rainmaker1973) February 21, 2025

Habitat range and invasive spread

Anacondas primarily inhabit eastern South American ecosystems. Their range includes Brazil, Colombia, Peru, and Bolivia. They favour slow rivers, swamps, marshes, flooded grasslands. These environments provide warmth, cover, and abundant prey. Anacondas remain submerged for nearly ten minutes.

This allows ambush hunting beneath water surfaces. Typical prey includes deer, capybaras, and caimans. Green anacondas also exist in Florida’s Everglades. There, authorities classify them as invasive predators. Limited natural predators allow population growth risks. Wildlife managers may require human-led population controls.

Hunting strategy size and conservation meaning

Anacondas kill prey using powerful constriction techniques. They do not rely on venom for hunting. Eyes and nostrils sit above water surfaces. This supports stealth attacks on unsuspecting animals. Death results from suffocation or organ compression. Prey is swallowed whole after successful capture.

Green anacondas can reach 26 feet maximum. Average adults measure between 15 and 20 feet. Females can birth 20 to 40 young. Newborn snakes already measure around two feet. Despite fearsome reputations, anacondas face growing threats. Habitat loss, hunting, and illegal trade persist. Conservation focuses on protecting river and rainforest systems. Scientists say fascination drives research and ecological awareness.