The Seattle Aquarium has Cuttlefish!

Exciting news! The Seattle Aquarium recently got 8 new dwarf cuttle fish (Sepia bandensis)! If you live in the greater Seattle area and want to check them out here are 10 facts to help you appreciate the little suckers.

1) Cuttlefish are the most recently evolved branch of the cephalopod family. While not a lot is known about the evolution of cephalopods, fossilized octopuses and squids were first seen in the Ordovician (488-443 mya) period and can be found in every ocean on earth. The first cuttlefish were not seen until the Jurassic (199-149 mya) and are only found in the shallow seas and found nowhere in the Americas. 

2) The cuttlefish family name Sepia has the same root as the name of the font. Ancient Greeks used to use dried cuttlefish sepia, or ink sacks, for dyes and writing ink. Eventually these writings and drawings became referred to as sepia. This association still exists in Sepia the font which looks handwritten or artisan. Additionally the family name for all cuttlefish is Sepia, again referencing this ancient relationship.

Due to their high calcium content, cuttle
 bones are commonly given to birds
as a supplement.

3) The cuttlefish common name is a reference to their modified shell called a cuttle bone. As cuddly as they look the cuttle in cuttle fish is actually a reference to their cuttle bone. In a second layer of confusing names, this cuttlebone isn't actually a bone but rather a modified shell. The "bone" is oval shaped and porous and used for buoyancy and to help the cuttlefish hover and float in the water column. 

4) Eight arms and two tentacles which end in sucker cups full of teeth just like squid. Also like squid, these two tentacles are used primarily for catching prey. Using their intricate camouflage they will hide in the substrate and wait for their prey to come by with their feeding tentacles coiled up among their arms. Upon spotting something tasty, they will shoot these feeding tentacles out and grab the unfortunate victim with clubs covered in suckers. To help their suckers hold tight, each one is lined with sharp teeth that can easily tear into flesh. (If you think those are scary check out the Humboldt Squid video. So many sucker teeth!) 

5) The Dwarf Cuttlefish use their arms to walk around while looking for prey. This is a behavior common to many of the smaller cuttlefish that live in particularly sandy areas. While they also swim and simply hover, the arm walking is pretty cool to watch.

Dwarf Cuttlefish holding
up arms to taste water

6) They hold their arms up to taste the water while hunting. Again like their other suckers cousins, cuttlefish have chemo-receptors or taste buds in each of their sucker cups. By holding their arms in front of their face (Halfway between an imitation of an elephants trunk and a rearing horse. Try it!) they are able to taste the water to see if any food is nearby.  

7) Multiple layers of chromtophores and can turn almost any color.All cephalopods have chromatophores. These are pigment cells that can expand and contract to change color. While octopuses color changing abilities are awesome, they pale in comparison to the cuttlefish. Unlike octos, cuttlefish have three layers of these chromatophores! The usual layers are a yellow on top, red/brown in the middle with iridescent blue/green on the bottom. By alternating the expansion and contraction of these cells, they can turn just about any color. In addition, these cells are very close together and very small. Studies have shown the resolution of a cuttle fish is around 350 DPI. The dwarf cuttlefish at the aquarium have been seen mostly turning yellow, brown, white and red.

8) Camouflage as a direct response to their surrounding. Unlike octopuses who have insticitve camaflouge patterns, the cuttlefish change as a direct response to their environment. If the rock is red, they 

turn red. They turn mottled and sandy while on sand. Studies have shown that against checkered background, they will turn checkered. What is even more amazing is the speed and versatility that cuttlefish use these colors. While octopuses will often change from pattern to pattern quickly, the cuttlefish can actually change their patterns continuously. In larger cuttlefish this display is usually seen as flashing and rippling bands of color along their arms. In the dwarf cuttlefish its simply a color change in their top arm while tasting the water for food or having the appearance of a cloud passing over their back. 

W-Shaped eye

9) Cuttlefish have a W shaped pupil that can see as well as ours can. Cephalopod eyes are very highly evolved and have a structure very similar to ours with the a similar eyesight capability as well. This is particularly amazing then you remember that they evolved from clams, which have to eyes at all! The main difference between our eyes and theirs, however is that they cannot see color. Science does not know how they are able to so accurately color match their environments while being color blind. 

10) All cuttlefish are venomous. Don't worry though, there are very few that are actually harmful to humans. The Flamboyant cuttlefish however is about as toxic as its cousin the Blue Ringed Octopus. Their lovely color patterns seem to say "Look, don't touch!".

Now you are prepared to both appreciate the cuttlefish while watching them and impress everyone you talk to! I will be on the floor at the aquarium from around 10am-1pm this and every Sunday. You can usually find me by the octopus tank. Feel free to stop by and say hi and maybe go check out the Ocean Oddities section.