Episode 231 – Bloodworm: Jaws of Strife

“…and today we’re talking about another beautiful sea creature that everyone will love to look at pictures of. But more on that later.”

The ocean is full of just chock-full of friendly and not-at-all scary things. One of those very fun things is the foot-long bloodworm with an extremely strong and painful, venomous bite. But how does this wistful worm use its toxic teeth to deliver its malicious munch? Let’s just say that nature is most definitely metal as we delve into the jaws of Life, Death, and Taxonomy.

Description of the Bloodworm

  • Bloodworms are segmented worms with semi-translucent skin, a toothy proboscis, and writhing parapodia.
  • They are so named because of their red color.
    • A close up of them is reminiscent of Peter Jackson’s King Kong. 

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 this week but we are going back in the archives to revisit greatest hits.


  • 14 inches (35 cm)
  • How many bloodworms go into the distance from the sun to the farthest orbiting object in the solar system?
  • Hint: Farfarout (or 2018 AG37) is a trans-neptunian object that was discovered to be the farthest object orbiting the sun. It beat out Farout, which is another object discovered the same year. It orbits so slowly, that observation for two years has not made it possible to accurately map its orbit. 
  • 56,514,285,700,000 (56 trillion) worms. The object is 132.2 ± 1.5 AU (19.78 ± 0.22 billion km).


  • Their maximum lifespan is about five years
  • How many bloodworm lifespans go into the length of the longest year of any planet in the Solar System?
  • Hint: Speaking of Neptune, it has the longest year of any planet in the Solar System, not including Pluto.
  • 33 worm lifetimes. Neptune’s year is 164 years and 292 days.

Fast Facts about the Bloodworm

Bloodworms live in tidal flats where they bury themselves in the ocean floor to prepare to ambush prey. 

They’ll pretty much eat anything they can fit down their gullet. 

Bloodworms are venomous, and kill their prey by injecting them with venom that’s stored in glands that are connected to their jaws. While they aren’t deadly to humans, their bite is extremely painful. 

They may be eaten by bottom feeders, other worms, and crustaceans. Because they live in tidal flats, they may be eaten by gulls, especially during low tide. 

The warm waters of midsummer trigger bloodworms to transform into epitoke, which is a non-feeding worm stage. Then they will swim up to the surface with other worms and release their gametes, which are fertilization cells. Then they die. 

They hatch as zooplankton. Then they cover themselves in a silk sock made of silt where they develop into the nasty red worms we know and love. 

They are commonly used as fish bait. While they can get you bites, they can give you bites as well. 

Major Fact: Jaws of Life

As if bloodworms weren’t bad enough, they also hold a special place among squiggly dudes as one of only two venomous worms. The other is the leech which just uses its venom to prevent its host’s blood from clotting.

So really the bloodworm is the only worm that uses toxins to kill its prey.

But how does it deliver its creepy crunch, its nefarious nibble? 

Well, as we mentioned, the bloodworm’s mouth has four black teeth-like jaws that hook inward like a baby sarlacc pit.

They’re not bones, like teeth, they’re jaws, so they are “not made within the confines of living tissue,” according to University of California researcher Herbert Waite.

These jaws are actually “made at the interface between living tissue and seawater.”

This is due to a pretty complicated chemical process that I’ll try and explain.

The jaws are made of protein, melanin, and copper – the bloodworm actually has the highest concentration of copper in its body than any other animal.

They are actually created by the protein binding to the copper and creating a hydrophobic compound (meaning it doesn’t occupy the same space as water and is repelled) that generates a version of melanin.

While melanin tends to form into blobs like it does in human hair or skin, this hydrophobia steers the melanin to come together and the three musketeers of proteins, copper, and melanin become rigid and form these jaws.

They’re also hollow inside like snake fangs. So these murder tubes actually technically spawn themselves.

Once a bloodboi has latched onto its prey, the paralyzing venom is injected into the poor sap. They also use the jaws as weapons to fight each other and defend themselves so stay away!

Ending: So always be ready for a fight, latch onto your dreams and don’t let go, and use your hydrophobic proteins to your advantage like the bloodworm here in LDT.