Answer:
Sturgeon
Step-by-step explanation:
The key has a series of dichotomies which are decisions that need to be made at different points and thus decide whether to go on one direction or the other until you reach one end of the key or the other. In this case, one end leads to Sturgeon and the other to Catfish. Both fish are similar in that they have a shark-like body. However, the sturgeon is the one that has a combination of the characters: A single dorsal fin, no fin on its back near the tail, and an asymmetrical tail (one lobe is longer than the other).