Capture a live fish is doing nothing. I've designated several fishing zones. I've put jobs in multiple fisheries. I've got dwarfs with fishing enabled. They pick up the traps from the stockpile. Then stand there. And do nothing until they are dehydrated. They don't even move off of the spot they picked the trap up at. I'm starting to think moghoppers are a myth. There are toads in the ponds to be captured.
I started a tester fort overlapping two savage biomes and cranked up fastdwarf.
I'm getting the same thing. The "capture a live fish" task conflicts mightily with the "fishing" labor. If there's no fishing zone when I tell them to "capture a live fish", they go to the animal stockpile and just stand there, holding their traps forlornly. If I designate a fishing zone, my six trapper/fisher dwarves dash out and capture a fishie each, and then... fish. Despite there being "capture a live fish"
R tasks queued in the six fisheries.
HOWEVER! One of them
did bring in a live pond turtle when I gave up on that and told them to get live
land animals. As moghoppers also have the [AMBIPHIOUS] tag, this would make it possible--not likely, but possible--that they can be picked up via kennels' "land animal" task.
I say possible-not-likely because in my real fort, what land animal you catch seems to be affected by either the frequency/quality of the vermin. Tons of rats and lizards, only the rare demon rat or fluffy wambler. I'd wager it's a combination of statistics (you have fireflies, dragonflies, monarch butterflies, roaches, slugs, snails, rats, etc.) and frequency (even if the frequencies were even, your odds would be less than optimal because of so many other possible trap occupants).
Those of us who fish for food will be aware that your given pond/river/ocean will only yield a few set species. Moghoppers, as far as I know, have never been catchable by the "fishing" labor, and it's still spring. I'm going to try tediously micromanaging my little dudes by turning the fishing zone for the pond that only yields pond turtles on and off, while manually checking what the
.s around it are. If that fails, I'll build a bridge across the river and find out what those evil-weather clouds do.
Oh, and the first place your dwarves will go when you give them a land animal task is your food stockpile. You could probably up the odds of them getting a moghopper if you placed your trappers in a burrow where the only food stockpiles they could get to were around murky pools.
[ETA] -- It's mid-summer and I've fished out all the murky pools on the surface. I have 125 pond turtles and not a single moghopper. Also, I was wrong--dwarves don't catch live vermin from your
food stockpiles; they catch it from
where your food is. (Which is usually the stockpiles, but hey, DF runs on technicalities.) Also, easy work-around for them preferring fishing over fish-catching: either inactivate the zone or turn off fishing once your trappers run out; wait 'till they're lurking in the animal stockpile and then turn the zone back on. Repeat until you are the DeBeers of pond turtles.