Ink Origins

One of the most notable facets of cephalopods is their ability to produce, and use, ink to their advantage. 

Published October 06, 2017

Cephalopods have not always had the ability to produce ink. Instead, they used their shells to defend themselves. According to the fossil record, the first ink sacs appeared around 330 million years ago. This shift distinguished cephalopods into different subclasses; Coleoidea is the class that produces ink, rather than uses a shell, for defense. 

octopus-swimming-ink

Octopuses, squids and cuttlefish fall into the Coleoidea subclass. These cephalopods evolved to include the ink sac in their biological repertoire of defenses. Today we know that ink sacs are used by these creatures to hold a mixture of melanin, enzymes related to melanin production, catecholamines, peptidoglycans, free amino acids and metals. Ink is used by most cephalopods to create a distraction, allowing them to escape from predators. There are also some studies that show that ink, in its mucus state, is irritating to fish gills, which adds an additional level of defense for these cephalopods. 

This evolutionary feat is one of many traits that make cephalopods unique! Stay tuned all week long as we share more fun facts about cephalopods. 

 
Previous Post

Featured Stories

Snapping turtle and red-eared sliders Floating Wetland Update: Turtles, Fish and Birds!

Several new species have been spotted on the National Aquarium’s floating wetland prototype in the Inner Harbor!

Read the full story

Edwin Hubble and George Washington Carver Animal Rescue Update: Double Seal Release!

For the first time in its history, National Aquarium Animal Rescue simultaneously released two rehabilitated seals. The two male greys, nicknamed Edwin Hubble and George Washington Carver, were released in Ocean City, Maryland, on May 23.

Read the full story

Related Stories

How Much Do You Know About Octopuses?

Published October 08, 2017

Cephalopods: Arms or Tentacles?

Published October 03, 2017