My apologies for those that have already read the following from me in the past, but unless your fish are constipated and require a diet high in fiber to clean them out, peas are NOT good for a fish - any species of fish.
Fresh/canned peas are a very poor form of nutrition for any fish.
Peas must be processed first, as they contain anti-nutritional matter, such as tannins, protease inhibitors, saponins, cyanogens, and phytic acid, which when consumed in excess can have a very negative effect on the growth & overall health of fish.
The anti-nutritional factors found in peas can vary greatly from crop to crop & season to season. Something as simple as dry weather, or a cold spell, can push tannin levels up drastically.
The heat from processing will reduce most of this antinutritional matter, but even then most fish can only digest & assimilate so much terrestrial based plant matter. All of this has been well documented in commercial aquaculture for many years.
The bottom line is raw uncooked peas are not nearly as healthy for a fish as many people believe.