comparing quantities

Question

I have read this link which explains how to say that something is n-times as big as something else. My sentence doesn't quite fit these patterns.

A fish has just been caught (no mention of size). The next sentence is:

岸辺を泳ぐ細長い魚の三倍はありそうなものだ。

So, I think it's supposed to be saying

(the fish just caught) seems three times as large as the long, thin fish swimming along the river bank.

But there is no adjective in this sentence. So I don't really know if it's bigger, smaller, fatter, or whatever. Is there a clue in the grammar I'm missing that makes bigger the obvious choice? Or, must I just infer it from context (though, I don't think the context makes it particularly clear)?

Answer 1

When we say 「N倍{ばい} + はある/である/だ/です, etc.」 without explicitly describing the quality that is being compared between the two objects (as to "N times as what"), it is always implied that the quality in topic is the size or amount in positive multiples.　

Thus, 「3倍{ばい} + はある/である/だ/です, etc.」 means "3 times as big/large/much (as the other one)".