Even Fish Can Do It.....

Who said that fish have a three second memory ?
Forget that nonsense.

I used to scuba dive for many years off the Mozambique coastline.
One of  my dive buddies was a guy named Hilton Jessiman. A likeable rogue.
No, make that a loveable rogue.
Anyway, Hilton had the habit of feeding a giant potato bass nicknamed Bertie.
Bertie was huge. Possibly 2,5 metres in total length and I estimate his weight at around 125-150kgs.

Potato Bass, like most reef fish, are territorial. Bertie's territory was a reef aptly named Bass City.
there Bertie lived with his wife Frederica and various smaller bass.

Hilton used to arrive at the reef with a gang of divers and Bertie would single him out within seconds.
So: Fish can remember specific individuals from others that are almost identical in appearance. (Scuba divers look very much the same when geared up)

Hilton would swim over the reef looking for a Blue Trigger Fish to offer up to Bertie. Hilton had the knack of pulling a Trigger Fish out of it's den. Bertie would snatch it out of his hand, but without harming Hilton.

Hilton 'introduced' me to Bertie. This required the other divers to move back about ten metres and keep still. Hilton lay on the sandy bottom with me next to him. Bertie came in closer, studied me for a few minutes then lay on his side and permitted Hilton to rub him down. I had to hold Hiltons wrist and then slowly move my hand onto Bertie.

Thereafter, when I went to Bass City, without Hilton, Bertie would come in close and let me rub his flanks. I never fed him, yet he always came to greet me.

Next Point.
Whenever floating around a reef, the resident fish swim close to the diver (me) and sometimes would nibble at my hair or hands out of curiosity. You become one of them.

However, whenever I saw a good eating fish, I would think of lemon and garlic butter, with a grilled fillet of fish. The fish would detect the slightest change in my posture or movement and even before I could get my knife out,  the fish (all of them) would disappear quite rapidly.

Conclusion: Fish are not stupid. They are as analytical as any other animal. They have excellent memory and detect predatory behaviour virtually immediately.