[Cuttlefish]: Ramses

[Hajar]

Just back from three days camping and I hear that Ramses has accepted frozen shrimps in our absence. We'll catch him some crabs again tomorrow though.

There was abundant evidence for the presence of cuttlefish strewn along the beach these past few days.

 

[zeekat]

Did you collect the cuttle yourself?

 

[DWhatley]

I wonder if they just went through a mating gathering, if you get into the water soon, you might want to look for egg clutches where you saw the last two adults.

 

[Hajar]

Zeekat, someone else had collected the cuttle and I found it in a local aquarium shop. They are always a delight to come across in the wild though, especially amongst the corals.

Good plan D, to look for egg clutches! I'll keep my eyes open.

 

[Hajar]

What's the best source of information on interpreting the meaning of the various colour and surface texture changes in cuttlefish? There was a lot of communication going on this morning, which I interpreted as "So where are the crabs?"

I'm just back from the beach with a selection, one of which is already caught and consumed.

Here he is this morning, up at the top of the tank, in the company of the crinoid.

 

[Hajar]

Ramses the jet-propelled.

 

[Hajar]

Ramses communes with the clam.

 

[cuttlegirl]

I think cuttlefish have two thoughts, food or mating. I'm guessing he is thinking you are a little slow with his breakfast.

By the way I'm in love with your cuttlefish, he is so cute.

 

[Hajar]

Thanks cuttlegirl. Ramses is endlessly fascinating to observe and very photogenic, but not everybody in the household admires him, this being the first predator to live with us. He was even described as "un monstruo" after the massacre of Tom the anemonefish.

Here attached is an image showing the location of "Cuttlefish Beach" and a surfing area on nearby Masirah Island for Zeekat.

 

[Hajar]

I just found this which discusses the two black marks on the mantle visible in the "Ramses the Hunter" video above.

They describe "the deimatic pattern" as a response to threat and call the two black marks the "deimatic spots (DS)". They write that cuttlefish in captivity readily display the DS .. to an approaching large object. Messenger and Miyan managed to induce the DS display by electrical stimulation of a branch of the fan of nerves running to the fin and dorsal mantle skin. Interesting.

 

[Hajar]

Here's one on camouflage and "motion dazzle" (look at the high contrast pattern just before Ramses zips away in the ".. jet-propelled" video above).

 

[DWhatley]

I wonder if the dark spots surrounded by light are supposed to suggest eyes for both eye protection and misdirection. There are potentially a similar pair of spots on the mantle of octopuses. I have been trying to find a description of their purpose but have not come up with any papers discussing it. When I look at diagrams, it appears they may be directly above the ink sacs but that is just guessing.

 

[Hajar]

Funny you should say that. Other people have had just that reaction, asking if they are "mock eyes".

 

[Hajar]

Ramses passing cloud.

 

[Hajar]

Ramses fails to catch the crab ..

He caught it on the second attempt though a minute later.