Some fish are very aware of people on the other side of the glass, not seahorses. Newcomers have now joined the original trio but, from their introduction, it has been impossible to pick them out. They too swim serenely, court and hunt in their separate, private, water world.
Some fish, especially our giant pufferfish Balloo and many of the more intelligent marine fish, are very aware of people on the other side of the glass. Whilst Balloo is interested - even friendly, some fish can be decidedly wary, especially when they first arrive.
The sea horses are quite the reverse. From the get go they appeared utterly indifferent to anything outside their watery world. You can watch them anchor themselves by wrapping their tails around a water weed frond as they hunt for tiny shrimps, or glide serenely across their tank like self propelled chess pieces.