My mom got a Betta fish as a class pet for her science class last year, and she let them choose a few different possible names then vote. They came up with a bunch of different crazy names (for example, the name that won the vote was Squirt) and she said that next year (or now it's technically this year) she would get an orange one and name it Dorothy. She didn't, though.
Then again, most middle school students would probably think she's crazy for naming the class pet after a furry red monster's pet fish.