Things You'll Need:
- Fish
-
Step 1
Look inside the fish's mouth. If there are teeth in the jaw, then this is not a freshwater carp. A carp's teeth are contained within the throat. They also do not have any bones in their mouths. A protruding jaw is another identifying characteristic of a carp.
-
Step 2
Check the dorsal, or top, fin of the fish. There will only be one dorsal fin and this fin will contain between 15-to-19 rays. The dorsal fin will have stiff spines in some species, such as the goldfish and common carp.
-
Step 3
Observe the other fins on the fish. In addition to the single dorsal fin, freshwater carp will have low pectoral fins and no adipose fin. There will pelvic fins on the abdomen.
-
Step 4
View the scales. Freshwater carp do not usually have scales on the head. Otherwise, the type of scales on the rest of the body tend to vary from almost non-existent to big, thick scales, depending on the type of carp. The common carp has thick and large scales.
