Yes, suggesting that fish can think or feel in the same way that we do is anthropomorphic.
People may think it sounds cruel or insensitive, but I'm of the opinion that half of the fish is missing and it's not going to heal properly, so it should be euthanized. If it cannot even right itself because it's being blown around the tank by a filter, it's time to make a decision. Unplugging the filter is going to cause a buildup of ammonia and/or nitrite, so now on top of missing half its body, it's also going to start slowly being poisoned by its own waste. It's making a bad situation worse.
If a fish were this severely injured in the wild, it would quickly be eaten by stronger, healthier fish.
People may think it sounds cruel or insensitive, but I'm of the opinion that half of the fish is missing and it's not going to heal properly, so it should be euthanized. If it cannot even right itself because it's being blown around the tank by a filter, it's time to make a decision. Unplugging the filter is going to cause a buildup of ammonia and/or nitrite, so now on top of missing half its body, it's also going to start slowly being poisoned by its own waste. It's making a bad situation worse.
If a fish were this severely injured in the wild, it would quickly be eaten by stronger, healthier fish.