is it an actual falsehood? it just says also called a Brazilian aardvark, which is true for at least one person in the world and became true for a lot more after reading it. it seems like the name stuck because people liked the name.
The "by whom" tag should be added to these unsupported claims. http://en.wikipedia.org/wiki/Template:By_whom
Weasel words are a way of introducing opinions disguised as facts while absolving yourself of the need to make a specific, verifiable (or falsifiable claim). "Some say Hacker News is the the most important website about startups." The actual information in that sentence is that 'some people say this thing' but it reads like 'this thing' which is misleading. It's misleading regardless of citations.
There is nothing wrong with saying 'this thing' if that is what you mean to say. 'The Arripis is also known as the Australian Salmon' is a true and relevant statement. It's common for fish to have different names in scientific, culinary and angling contexts as well different places. Wikipedia needs to address that to be useful.
That's the reason weasel words are a hard problem. It's subtle. Sometimes opinions are important and relevant and they should be included (with citations) on their own merit. "Commonly referred to as.." is an important fact about lots of animals.
What this is is basically just a simple case of falsehood. Nobody called anything a Brazilian Aardvark at the time of the edit. It wasn't true. It's an interesting story because it became true.
Every common name for an animal had to be invented at some point. Here, because of the magic of wikipedia' revision history we can see exactly when that happened.
Sure, but it's still weasel words unless it is accompanied by a citation from an authoritative source. If some random guy knows that fish as the "foobar fish," you could say "The Arripis is also known as the foobar fish." In this case, a Wikipedia contributor could rightful add the "by whom?" template tag. If there's no source cited, the statement should be removed, and if the source were cited, it would say that this name comes from some random guy, not the community of biologists, and would therefore be removed due to being irrelevant.
> Nobody called anything a Brazilian Aardvark at the time of the edit. It wasn't true.
From my understanding, the person who added that claim probably did call it a Brazilian Aardvark, so a claim like "it's called the Brazilian Aardvark" technically is true. But that's irrelevant to the weasel word diagnosis. Regardless of whether any human actually does call it that, there needs to be a source cited.