It's absolutely fine to feed our freshwater food items to saltwater fish. It shouldn't be considered a meal replacement. I think that's where people run into the problems we hear about, when the freshwater food is the main bulk of the diet. The hardest issue to overcome is the "wrong fats". Marine fats are only in marine fish. There is nowhere else to get it. It will eventually be an issue for you and I as the stocks of the sea are depleted and the numbers on land increase. There are so many studies going on right know to try and find an alternative. You'll also hear people speak of thiaminase that is found in freshwater fish. It is known as an anti-vitamin and basically renders the Thiamine (Vitamin B1) in your body ineffective. What people don't realize is that marine fish can have that as well, it just happens that the freshwater ones we were commonly using as feeders (carp/goldfish) had it. Not all freshwater fish have it either.
What I "love" hearing is "I've been feeding my fish [insert inappropriate food or feeding regime here] and they are perfectly fat and healthy, so it's fine. That's an eye roller for me. Here's a couple of examples of how the evaluation of their fish is inaccurate. There's a little girl who is now 13 that has a eating disorder. She has only eaten Ramen Noodles for those 13 years. It wasn't her primary food, it was her only food and that's how she made the news. She's alive. She a beautiful young girl and it's not something you can tell. She looks perfectly healthy. Would anyone here say that is a healthy diet? Anyone?
I remember a 95 year old man was in hospital dying. He smoked since he was 12 and never had any ill effects that were evident. It certainly didn't kill him. Would anyone here say that was a healthy habit? Anyone?
It's the same as "gold fish are perfectly fine to feed because my fish have lived a long time and they look fat and healthy"..... Now, would anyone say it was healthy based on the assessment provided... alive.... fat.... healthy. That's like saying smoking and a 100% diet of ramen is good for you.
*eyes rolling*
Unbeknownst to some of us, we are feeding out freshwater fish anyways. There's a food called Silversides that a lot of preds eat.... did you know that a couple of the popular brands sell "freshwater silversides" to our marine fish? PE mysis is also sold to us and that's a freshwater 'shrimp".
