Which animal has the longest intestine in the world? Surprisingly, scientists don’t actually know for sure – but they have a pretty good guess...

Which animal has the longest intestine in the world? Surprisingly, scientists don’t actually know for sure – but they have a pretty good guess...

Ever wondered which animal has the longest intestine? Well, so do scientists...


Blue whales reach lengths of nearly 30m and may weigh up to 100 tonnes. They are the largest animals to have ever lived on Earth – and, as such, are likely to have the longest intestines as well. Records of blue whale dissections are scant, though.

While once hunted by whalers (records show that some 340,000 were killed in the first half of the 20th century), these seamen were more interested in the whale’s blubber than its other impressive anatomical details. Contemporary dissections of beached specimens don’t appear to have recorded intestine length either – given the logistical difficulties and general unpleasantness of unravelling endless coils of digestive tract from a decaying behemoth.

Estimates of intestine length are instead inferred from the whale’s massive body size – scientists believe it is likely to be 150–200m long. The diameter of the intestine is around 20cm. This gargantuan gut helps the animal to process the 16 tonnes of krill it eats every day – resulting in bowel movements of up to 200 litres at a time.

The blue whale is not alone in this impressive alimentary achievement: sperm whales may have intestines of equal or even greater length according to some sources.

Discover more amazing wildlife stories from around the world

Top image: a humpback whale. Credit: Getty

This website is owned and published by Our Media Ltd. www.ourmedia.co.uk
© Our Media 2025