Only if they are undersized.
But then if they are for educational purposes, you can get a permit to keep them.
That goes for any fish that has a size limit.
A strange one is the whitebait.
It can only be caught in a set seasonal time, but once it gets past that stage of their infancy, you can catch them anytime.
It is frowned upon tho to go for the adults, as the fish themselves, can be a bit difficult to rear, and taking the breeders,
means you are depleting an area of the reproduction potential of the area.
I know of a small stream, just north of Matata, that was raped by a certain breeding facility in the Hawkes Bay.
Using electronic fish stunners made it very easy to get them, and I heard that they did not survive.
So now that stream is poorer for the acts of a firm, after a quick buck.
If they had gone for the young ones, grown them on, they would have had a more successful survival rate.
But then, due to the fact that the embryo return to the sea,
I fear that their efforts were bound for failure, and sadly,
the effect on the stream's fish will take years to recover.
I also think that it was the results of a NZ fresh water native fish club having fished there,
put in a report to DOC to which the public have access to,
probable lead to that firm knowing of the huge potential of that stream.
It was noted that it probably held more species than most waterways in NZ.
That was from DOC, not me.
Alan 104