Whoops, sorry guys. You're right, I goofed and didn't pay attention. It's fixed now.
As for the "wolf fang" thing mentioned above: "Rouga" is wolf fang, and all Oda did is insert the kanji (and thus the pun) into a normal sentence.
Many Japanese words have a "volitional" form that ends in "rou" or "ou" (depending on what type of word) which basically states a desire or will to do something. In addition to simple verbs (i.e. "Let's eat something") it can also apply to the copula verb "desu" or in this case "da" which predicate the sentence and make it a statement, a bit like the use of "is" in English (this IS a sentence). When you add the volitional form to the copula (da rou), it makes the sentence read "should be/ought to be." There are several inflections in the way this can be stated, but to keep it simple, in the very crude and blunt way that Sanji and Jabura are speaking to each other, slapping this form at the end of the sentence is like adding a "Right?" or "didn't/don't (I/you)?" By adding the particle "ga" at the end (da rou ga) it becomes very crude and no longer a question, but instead just a very forceful statement. So everytime they make this pun (da ROU-GA) in this chapter it's stemming from this form.
That's a very basic and non-technical explanation, but IANAJapaneseTeacher so it's the best I can do.