Yes
Obviously, you are referring to the 'Dietary Rules' found in Leviticus 11 and Deuteronomy 14. The answer then is yes as sardines or pilchard have both fins and scales and may be eaten. Predominantly then, shellfish, sharks, swordfish, and catfish do not have either fins or scales or both and are prohibited to be eaten.
No it does not have scales, and yes, it has fins
Yes, they do have both fins and scales.
yes
Sardines are not scaleless fish. They have scales.
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.
Most. There are very few fish that have no scales and all fish have fins.
Pacu are a type of piranha. They do have scales, like most fish, as well as fins.
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).