This is something I first noticed when I was at an aquarium in Japan (as evidenced in my examples) and continued to see ever since. There are certain pairs of animals, that while extremely similar, have certain distinguishing characteristics such that English speakers (well, most anyway) know them apart; or at least that they are different animals even if they don't know which is which.
** Disclaimer - I'm no animal expert, so I may mix up these pairs, but I'll try to Google them to be sure. **
crocodiles. English speakers know these are different even if they're not sure what the differences are. Alligators have broader, rounder snouts, while crocodiles have longer, pointier snouts. Also something about the teeth. But in Japanese, they're both just
ワニ. I asked my Japanese friend, and he said the average Japanese person doesn't know this difference or is even aware that they are considered different animals.
Here are several other pairs that seem to just get lumped together in the same Japanese word (by the average person):
- Turtle (flat wide shell) vs. Tortoise (large dome shell) → 亀【カメ】
- Seals (have fur; concave ears) vs. Sea Lions (smooth body; extruding ears) → アシカ
- Dolphin (have a "beak"; spiky teeth) vs. Porpoise (no beak; flat teeth) → イルカ
Even pairs that are blatantly different often get grouped:
- Crab vs. Lobster → カニ (not sure if Japanese people use ロブスター or not)
- Mouse vs. Rat → ネズミ
- Monkey vs. Ape → 猿【サル】
There are many other examples, but these are the only ones I can think of right now. I'm sure the
学名 are different, but like I said, it seems like the average Japanese person doesn't make, or even know of a difference in these pairs. Why is this?