This discussion will rage until next week when we get the answer, it seems BUT taize, I am afraid Chambers does not show gade as a small fish:
Gadus
n the cod genus, typical of the family Gadidae .
[Latinized from Gr gados the hake or similar fish]
gade or gadoid n a fish of the genus Gadus, to which the cod and hake belong.
gadoid adj belonging to, or resembling, this genus.
To me the question is asking for the ORDER of fish to which Cod, Whiting etc belong and that is Gade.