Episode 315 – Giant Squid: An Esophagus Runs Through It

“…and today we’re talking about the grumpiest cephalopod in the sea. More on that later.”

Brains and digestive systems are linked just like all systems in the body are linked. But with the strange tube-like body shape of the giant squid, these two systems need to be a bit closer than they’d like. When you’re a squishy Lovecraftian toilet paper tube at the bottom of the ocean, you gotta play some organ Tetris to fit everything where it’s supposed to be. But sometimes literally threading the gastrointestinal needle is how you get by here in Life, Death, and Taxonomy.

Description of the Giant Squid

The giant squid has a mantle, eight arms, and two elongated tentacles.

Arms are shorter and have suction cups along their entire length. Tentacles are long and only have suction cups on the ends.

The arms and tentacles bear suction cups lined with sharp, serrated rings, leaving circular scars on sperm whales that engage with them. 

They have very large eyes, which help them see in low-light conditions.

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro!

Creature Culture: Hannah Barbarah’s Squiddly Diddly


  • 5 m (16 ft) including arms, can grow to be up to 30 feet.
  • How many giant squids go into the length of Queen Anne’s Revenge?
  • Hint: Queen Anne’s Revenge is the legendary pirate ship captained by Edward “Blackbeard” Teach. In November 1717, it was captured by pirates while it was being used as a French slave-trading vessel. It eventually ran aground off the coast of North Carolina in June of 1718. 
  • 6.4 squids. The ship was 103 ft (31.4 m).


  • 275 kg (606 lb) 
  • How many giant squids go into the weight of the stern post that was recovered from the wreckage of the Queen Anne’s Revenge?
  • Hint: The wreck was discovered in 1996 and it took until 2011 to collect enough evidence to confirm the ship’s identity. The post was recovered in 2007.
  • 2.4 squids. The post was 1,500 pounds.

Fast Facts about the Giant Squid

Giant squids use small fins on their mantle for movement and jet propulsion for speed, breathing through gills in the mantle cavity.

Giant squid and some other large squid species maintain neutral buoyancy in seawater by using an ammonium chloride solution, which is lighter than seawater and found throughout their bodies. This solution is said to taste like salty licorice and makes it bad eatin’ for humans. 

Like many cephalopods, they use jet propulsion to get around. They pull water into a cavity in their mantle and then force it out quickly with muscular contractions. 

They enjoy eating deep-sea fish and other squids and are probably solitary hunters. 

We don’t know how many there are in the world. Scientists have tried to guess based on the stomach contents of sperm whales. They think their numbers are well into the millions. 

Major Fact: An Esophagus Runs Through It

There are four major types of digestive systems for multi-cellular organisms:

  1. Monogastric – mouth, esophagus, single-chambered stomach, intestines, and ending portal. Just a straight shot to the finish. (humans)
  2. Avian – food that travels down the esophagus is stored in a crop before moving on (birds)
  3. Ruminant – multi-chambered stomach for regurgitation and re-chewing of food (cows)
  4. Pseudo-ruminant – pretty much a monogastric system but specialized in eating the same high-fiber diets as ruminants (horses)

The squid has a monogastric digestive system, like humans, but it is not even a little bit like humans. Squids need to play some organ tetris to fit in their tubular bodies. Their brains are shaped like donuts. They’re ring-shaped. Their large optical lobes (especially large for the giant and colossal squid, who have the largest eyes in the animal kingdom) branch out from this brain ring.

The giant squid also has these little floating bone structures called statoliths that allow the squid to tell which way is up when swimming in the black depths of Davy Jones’ Locker.

However, the esophagus starts at the beak at the center of the arms and extends straight through the squid’s body and through the ring. So, if the squid eats something too large, it could stretch the esophagus to the point of stretching the brain and causing brain damage. 

Because of this, the giant squid uses its beak and rough tongue to tear its food to shreds bit by bit so that none of the bites are too big.

Ending: So find some food, beak it good,  and don’t eat big bites or you’ll get big brain hurts like the giant squid here in LDT.