Well I think that your fish is very very sick. If I were you I would take your fish to a local vet or pet hospital. But what should I know I am only 13.
Yes, they do have both fins and scales.
No it does not have scales, and yes, it has fins
There are many classes of fish which do not have scales nor fins. The Agnatha has neither fins nor scales; the Condrichthye, including sharkes, rays and skeats have fins but no scales; the Ostichthyes, of which several families have members with the common name, mackerel, with both scales and fins. The King Mackerel, S. cavalla, has very tiny scales and fins.
Yes all tuna have fins and scales
Tilapia fish has fins and scales like any other fish. The tilapis fins and scales are less difficult to remove.
Yes all species of Tuna have both scales and fins.
Fins are used for direction. For example: A shark uses it's fins to descend, ascend, turn, and swim through the water. Scales are important because they act as an animals natural armor. For example: An alligator or crocodile use their scales to protect themselves from an animals hooves, teeth, or horns. -Haley Brown
Pacu are a type of piranha. They do have scales, like most fish, as well as fins.
Most. There are very few fish that have no scales and all fish have fins.
Yes it does
Yes
Yes, Salmon do have fins and scales like most fish (although som fish, like catfish, do not have scales). I have never heard of a fish without fins, although eels have less fins than many other fish. The scales tend to be small and most fish vendors will sell salmon fillets with the skin and scales still on (although some people think the scales are unpleasant).