They are called a Red Wagtail Sword.
The Blacktip Reef Shark is called such since it lives in coral reefs and its fins are black at the tip.
the tail fins of a bottlenose dolphin are called flukes
black
A black & orange fish.
fins
The tail fins are 'flukes'. Otherwise the fin on any marine animal is "... fin" where "..,." is the adjective denoting its position on the body.
Fins have rigid bones that are called spines, although they are not connected to the actual spine. Rays are made of cartilage, not bone. Sometimes fins are called fin rays, but they are not true rays.
well the fins on its side are called flippers and the fin on its back is called the dorsal fin and its tail is its tail flukes
well the fins on its side are called flippers and the fin on its back is called the dorsal fin and its tail is its tail flukes
Your albino Oscar's fins should not be turning black under normal circumstances. They can be turning black due to conditions such as too much ammonia in the water. Get your water tested to make sure.
A reptile?
fairwater planes