Blotches on the dorsal fin and tail fin(s) can be the diseases fin and tail rot, easily cured with medication.
A goldfish has about 1,500 bones inside of it.
There are two Dorsal fins on a perch. The anterior and posterior Dorsal fins.
Porpoises have triangular dorsal fins (as opposed to the curved dorsal fins of dolphins and whales). Some species of porpoise have small bumps on their fins, but the purpose of these bumps is unknown.
Sharks have straight dorsal fins, dolphins have curved dorsal fins and whales don't have dorsal fins :)
Goldfish have 1 dorsal fin, 1 caudal fin, 1 anal fin, 2 pectoral fins and 2 ventral (pelvic) fins. They do not have a spiny Dorsal or an adipose fin so that makes them a 7 finned species. Breeders have devloped goldfish with different types of split Caudal (tail) fin but they are still single fins. These "sports" are commonly called Veiltailed, or Fantailed fish. (There are many other names of "goldfish sports" too). To the best of my knowledge they do not however have 8 fins. They have seven fins but the tail has been modified by selective breeding to look like more than one fin. (Breeders have also developed a type that has no dorsal fin which makes it a 6 finned fish).
Yes, giant cat fish do have dorsal fins.
The commonest cause of fin nipping in Goldfish is insufficient food and/or poor diet. Fish should be fed a good quality goldfish food morning and evening as much as they can eat in 15 minutes.
Well to start, the goldfish has two eyes, two nostrils, two gill covers, and a mouth. Then comes the two major parts- the head and abdomen. And lastly their are the fins: the pectorals, the pelvic fins, the caudle fin(s), the anal fins, and the dorsal fin.
Yes, shark dorsal fins are triangular and straight while dolphin dorsal fins are very curved and streamlined. A Google Image Search will clarify this even better.
dorsal fins
Goldfish do not have legs. Goldfish do have fins, although the number of fins will depend on the type of goldfish.
a goldfish uses his/her fins for direction when it swims.