Those look like
sepia bandensis. I attempted keeping a couple of those about the same size. They were so awesome...but I had a power outage unfortunately and they both didn't make it (it was a short power outage so I assume the temp drop or 02 drop was too much for them at such a small and fragile size). I've been dying to find some more cuttles to try but I haven't had any luck.
ANYWAYS...if you don't want to breed mysis or whatever, I just collected some amphipods from the local beaches (Nahant beach is where I went) but just make sure the beach isn't a complete dump. I just went along the rocky tide pool areas during low tide with a fine mesh net and just scooped under the seaweed attached to the rocks a couple times. In about 5 mins I had enough amphipods to feed the cuttles for seriously like...3 months. I put them in a bucket with an airstone and dropped some flake food in it every day. They stayed alive like this for about a month (probably longer had I attempted to keep them alive after my cuttles died).
Whenever I wanted to feed the cuttles I just dropped my net in and picked out the smaller ones that I knew the little cuttlefishes could eat. I dropped like 2 or 3 for each cuttlefish. The next time I fed the cuttlefish, I checked and made sure most of the other amphipods were already eaten and removed the dead ones (they are cold water amphipods so they don't last very long (~2 hours) in reef tanks) before dropping some new ones in. Its pretty important that they eat often when theyre such a small size but they grow quickly. I fed 2x/day. Sometimes 3x times whenever I had time. I had them eating like crazy and they were very healthy until that fateful day the power went out.
When they get bigger (ie. 1"), I heard you can start waning them onto larger foods and this is apparently when you should/could start trying to get them to eat frozen. I heard if they don't initially have a taste for frozen, you can feed them some live small shore crabs or ghost shrimp. Then once they get used to it, skewer the live crabs/shirmps onto clear acrylic rods. Then once they get used to THAT, you skewer dead ones on it. Then after THAT, you skewer frozen on it. I heard that's the best way to get them to eat frozen if they dont bite during the first few attempts.
In any case, I hope you found my tips helpful. Good luck and keep posting pics! Oh yeah and I call dibbs on a couple if you get them to breed!

P.S.
Where did you get the cuttles anyway?