Some sharks have a second dorsal fin, it's between the main dorsal fin in the middle of the back, and the tail. Not all fish have a second dorsal fin.
The Fin Whale.
Fin Whale (Balaenoptera physalus)
The Fin whale [second to the blue whale] is the second largest animal on our planet.
Fin whales are the second largest whale. As well they are the second largest living animal on earth behind the blue whale. The can weight up to 80 tons and be at length of 72 feet.
Either the fin whale (Balaenoptera physalus) or the bowhead whale (Balaena mysticetus). The former can reach lengths of 89.5 ft (27.3 m) but only weighs 70 metric tons, while the latter reaches lengths of 65 ft (20 m) and weighs over 100 metric tons.
A Sei is a type of Whale, a fin is what fish have on their sides and top. There is also a whale called the fin whale. It's also called the finback, razorback or rorqual. It is the second-largest of all whales. (The sei whale is the third-largest.)
The word "finial" is pronounced as "FIN-ee-uhl." The emphasis is on the first syllable, "FIN," with the second syllable pronounced softly as "ee" and the final syllable as "uhl."
The fin on the back of an orca is called the dorsal fin.
The dorsal fin is the fin on the back of a fish, for example the typical triangular fin on the back of a shark is its dorsal fin.
An adipose fin is a soft, fleshy fin found on a fish behind the dorsal fin and ahead of the caudal fin.
If you mean a fin like a fish fin, there is a word, but mostlly each one is different; Lā (fin). Anal fin, kuaalo. Caudal fin, hiʻu. Dorsal fin, kualā. Pectoral fin, etc. If you mean fin, like 'the end', it is pau'ana.
Soup fin is shark fin used in making shark fin soup.