With baited breath.
If under the influence of awe, terror, or other emotion, your breathing is bated, subdued or restrained - go fishing until you catch it again.
Of course bait brings images of maggots, rotten meat & fish hooks – very bad breath indeed.
On the other hand, to a fish at least, it is alluring, enticing, & attractive
And it is one of those phrases we seem to have Shakespeare to thank for:
Shall I bend low and in a bondman's key,
With bated breath and whispering humbleness, Say this;
'Fair sir, you spit on me on Wednesday last;
You spurn'd me such a day; another time
You call'd me dog; and for these courtesies
I'll lend you thus much moneys'?
Shylock to Antonio Act 1 Scene 3 Merchant of Venice