[Octopus]: Please reply ASAP: senescence?

[Squirrel1]

Hello everyone please answer this as soon as possible. I am extremely worried about my octo.
He has been acting very unusually compared to my other octopuses, and has not eaten for almost a week, at least I don’t think so.
First of all, as stated above, he has not eaten for a very long time. ?
He has interacted slightly, but something was weird; when I tried handing him food from my hand he jetted away after touching it. ?
He the same thing happened today when he grabbed onto the tweezers very tightly but then all of a sudden shot away. None of my other octopuses have minded the tweezers. ? Then after that he went crazy all over the aquarium, crawling in and out of the intakes super quickly and not caring about me watching him closely like he usually does. I had just added crabs and a snail to the tank.
It seems like senescence but after his frenzy he calmed down again, peacefully wandering the tank and reacting to stimuli as usual. ?
I am very worried and very confused right now so any suggestions or ideas will be thanked.
Here is a photo of him after he calmed down... still hoping to see if someone can tell the species:

 

[DWhatley]

Sadly, the photos are to dim for an ID.
You could be facing senescence but the odd reaction could also reflect water problems.

Check your PH (target should be 8.2-8.4) and salt (target 1.024-1.026 specific gravity/~35 parts per thousand). Either of these being out of range can cause odd reactions. If you find they are off, SLOWLY bring them inline over a day or two.

Also check for ammonia or nitrite. If you find either, do several large water changes each day until they fall to zero.

 

[Squirrel1]

Sadly, the photos are to dim for an ID.
You could be facing senescence but the odd reaction could also reflect water problems.

Check your PH (target should be 8.2-8.4) and salt (target 1.024-1.026 specific gravity/~35 parts per thousand). Either of these being out of range can cause odd reactions. If you find they are off, SLOWLY bring them inline over a day or two.

Also check for ammonia or nitrite. If you find either, do several large water changes each day until they fall to zero.

Did a water change, and now he eats weird... I did a water change only five days ago