Oncorhynchus keta and Salmon

Oncorhynchus keta noun - A large Pacific salmon with small spots on its back; an important food fish.

Salmon and Oncorhynchus keta are semantically related. In some cases you can use "Salmon" instead a noun phrase "Oncorhynchus keta".

Salmon noun - Any of various large food and game fishes of northern waters; usually migrate from salt to fresh water to spawn.

Oncorhynchus keta and salmon are semantically related. Sometimes you can replace phrase "Oncorhynchus keta" with "Salmon", this terms are similar.