Many people are under the impression that JDs are carnivores, eating only meaty foods.
The reality is they are omnivores, and when analyzed, the stomach contents of wild JDs was half filled with filamentous algae which grows profusely in the habitat, and detritus (such as leaf littler), the other half aquatic insects, hardly ever fish.
I always found a pellet high in sprulina algae such as (AlgaeMax) worked well.
I have snorkeled with them, and watched them try to eat live bearers they are surrounded by in nature, but noticed they missed at least 9 out of 10 times.

2 videos of JDs in nature below,
Cristalino
Eden2
The reality is they are omnivores, and when analyzed, the stomach contents of wild JDs was half filled with filamentous algae which grows profusely in the habitat, and detritus (such as leaf littler), the other half aquatic insects, hardly ever fish.
I always found a pellet high in sprulina algae such as (AlgaeMax) worked well.
I have snorkeled with them, and watched them try to eat live bearers they are surrounded by in nature, but noticed they missed at least 9 out of 10 times.

2 videos of JDs in nature below,
Cristalino
Eden2