Rejected for the reason that “similar content exists in the Adobe collection.”

You have multiple subjects, each with good representation.

https://stock.adobe.com/search?k=fish 12 MILLION results

https://stock.adobe.com/search?k=coral 3.3 MILLION results

https://stock.adobe.com/search?k=aquarium 2 MILLION results

https://stock.adobe.com/search?k=frog 800K results

https://stock.adobe.com/search?k=ladybug 400K results

Nobody knows how the algorithm works. But if you add all these results together, that's a big number.

Same problem here with my images! Unfortunately I'm already giving up, because I also saw that no content was the same as mine because I make thematic illustrations. I believe that the amount of images sent has increased a lot because of the AIs and the algorithm should be rejected.

This is a common refusal reason for many contributors these days, starting a few weeks ago. The rejections are often illogical or seemingly random. Unique assets are being rejected, while actual "similar" assets are being accepted (wallpapers and background, for example). It may be related to the keywords being used or titles. (My opinion, not necessarily fact.)

That said, I think the contrast is low, it's slightly underexposed, there are "dust spots" on the glass, and its aspect ratio is the typical default square format of AI. I'd fix those and try re-submitting.

It is now apparent that the algorithm Adobe uses to verify similars throughout the entire database is somehow flawed and sometimes rejects unique images. Unfortunately, there doesn't seem to be anything we can do about it except complain.