Netting (quick) fish in established (planted) systems

[Andyroo]

Ok, so...
Trying sherry (blue) shrimp, several months later & I've finally three berried females soon-ready.
Skeletal sea-sponge & vining-type water plants & bamboo segments etc etc. in an ~15gal
Re-shrouded filter intake with a large surface area of finer sponge.

Initially the Internet told me that lemon tetras would be fine, so I left them there. Now I'm thinking, as corroborated by other online shrimp-people, that it's not a great idea.

Tried to remove the lemons over the weekend & it was a mess, I gave up before scooping a single.
Suggestions on how to scoop'em out without dismantling the system (& disturbing shrimpses)?
I'm tempted to let it/them ride & rely on the habitat complexity.

Or get these shrimp cohorts through (partial) & then tear-down the whole thing?

 

[jjohnwm]

I agree that if you want to breed shrimp, most fish will be counterproductive to your efforts if maximum productivity is the goal. Some newly-hatched shrimp are gonna get eaten, no matter how much cover there is, no matter how well-fed you keep the fish; nothing you offer in the way of food will be as attractive as a live, healthy, wiggling little shrimplet.

Do you really need or want every single shrimp hatchling to grow up and lead a rich full life? Is a certain amount of attrition acceptable? If it is, leaving it along might be the best bet, and certainly the easiest and least stressful.

But if you must remove the mini-predators, a small net and larger one worked in concert will be your ideal tools. The big net should be black (less visible), the smaller one doesn't matter. Place the big net in position, ideally to block an entire travel pathway, and the herd the fish towards it with the smaller net. Don't move the big one until you have one or more fish in it, then just lift quickly straight up. Leave the tank to calm down, then repeat the exercise. Expect this to take a couple days to get all of the fish.

You can also buy a minnow-trap at most fishing tackle stores. Whether or not it works will depend upon the species. Some types of fish see one of these things and practically fight with each other to be the first one inside; other species will never go near the thing. But they work so well so often that they are definitely worth trying, and worth having in your arsenal for future use.

 

[duanes]

I remove about 90% of the tanks water (maybe more) makes them easier to catch and consider it a great way to do a large water change.

 

[danotaylor]

You could also try after lights out when the tetras are sleeping, turn an indirect ambient room light on and catch them out gradually over a few nights. I have used this method successfully to catch smaller fish in my 560 gallon tank. All the best

 

[Andyroo]

duanes - I expect this is where I'll go once this first egg-cohort comes through... and/or disappears. E-gurus suggest that the shrimp might abandon eggs (early) if stressed, so I'll let it ride for a few more weeks. A drain-down will let me get back on top of the ostracods, also (lemons don't seem to eat them)​

 

[RyanScanner]

I just bait mine in a small micro fibre sock with algae pellets inside hanging halfway down. Within an hour it’s full of shrimp. Within a few hours it’s also full of snails. Can’t use a net because they just eat what falls through.

I’ve got so many now I’m just feeding them to fish. 20 has turned into few thousand in a year.

 

[TheWolfman]

if breeding shrimp is the goal then your definitely going to want to remove the fish. Remove any large rocks or driftwood and do a drain as much water as you can. That will make it easier to net them. Then you can just refill the tank back up with the old tank water.

Cherries are a blast and once you go species only their population really takes off. I love the different size shrimps it really is rewarding and mesmerizing to just watch them do shrimpy stuff.

 

[jjohnwm]

I just bait mine in a small micro fibre sock with algae pellets inside hanging halfway down. Within an hour it’s full of shrimp. Within a few hours it’s also full of snails. Can’t use a net because they just eat what falls through.

I’ve got so many now I’m just feeding them to fish. 20 has turned into few thousand in a year.

Wait...are we talking about removing the fish or the shrimp? Trapping and removing the shrimp is child's play.

Once your population takes off, you'll need to start targeting the poorly-coloured ones for use as feeders. If you just let them breed willy-nilly, you'll start to see a lot of dull-coloured ones, more and more as time passes. It's...it's almost as if Nature is trying to create less-obvious brown shrimp that are harder for predators (in this case, Tetras) to find and eat. Somebody needs to do a study on this phenomenon...

If breeding shrimp is the goal then your definitely going to want to remove the fish. Remove any large rocks or driftwood and do a drain as much water as you can. That will make it easier to net them. Then you can just refill the tank back up with the old tank water.

Cherries are a blast and once you go species only their population really takes off. I love the different size shrimps it really is rewarding and mesmerizing to just watch them do shrimpy stuff.

I think the whole idea of the question was to avoid messing up a beautifully planted tank by removing all the decor. Even taking most of the water out will cause all the plants to just collapse into a jumble on the bottom with the fish hidden inside.

IMHO, if you decide to drain some or most of the water to catch anything in the tank...or really any other reason...there's no power on Earth that would make me put that old water back in afterwards. That's about like draining the old oil out of your car, and then just putting it back in rather than changing it. Why would you do that?

Dirty old water isn't precious; it's just dirty old water. That's why we change it.

 

[TheWolfman]

Wait...are we talking about removing the fish or the shrimp? Trapping and removing the shrimp is child's play.

Once your population takes off, you'll need to start targeting the poorly-coloured ones for use as feeders. If you just let them breed willy-nilly, you'll start to see a lot of dull-coloured ones, more and more as time passes. It's...it's almost as if Nature is trying to create less-obvious brown shrimp that are harder for predators (in this case, Tetras) to find and eat. Somebody needs to do a study on this phenomenon...



I think the whole idea of the question was to avoid messing up a beautifully planted tank by removing all the decor. Even taking most of the water out will cause all the plants to just collapse into a jumble on the bottom with the fish hidden inside.

IMHO, if you decide to drain some or most of the water to catch anything in the tank...or really any other reason...there's no power on Earth that would make me put that old water back in afterwards. That's about like draining the old oil out of your car, and then just putting it back in rather than changing it. Why would you do that?

Dirty old water isn't precious; it's just dirty old water. That's why we change it.

Sometimes there’s not a choice you need to take some stuff out to net a problem fish. The plants will be fine lowering the water. To answer your question draining the water out and keeping it to refill the tank back up is totally fine. In fact with invertebrates your better off not doing a major water change or you run the risk of stressing out the shrimp and causing them to all molt also any berried shrimp will loose their clutches. It is definitely in no way equivalent to reusing motor oil.

 

[jjohnwm]

... E-gurus suggest that the shrimp might abandon eggs (early) if stressed, so I'll let it ride for a few more weeks. A drain-down will let me get back on top of the ostracods, also (lemons don't seem to eat them)​

They probably would eat them, if they didn't have all that tasty shrimp-candy around.

The stress that can cause shrimp to drop their eggs would be much more extreme than merely rummaging around in the tank with a net, or removing decor; more along the lines of actually netting and removing the shrimp themselves. I think the people who warn against that are probably convinced they have "bonded" with their shrimp...