How to make a bottle trap - picture

[Betta132]

Doodled up a quick thing to show how to make a bottle trap, and also kind of how it works.
Your critter comes crawling in, up the ramp provided by the curve, but when it turns to leave it discovers that there's something in the way. Very few creatures ever figure out how to get out. The larger the hole, the more creatures you're going to catch.
This trap can catch most shrimp, many crabs, some snails, and often any gobies that scoot around on the bottom.
If you're going after a mantis or a pistol, one large hunk of food is good. If it's smaller critters or you're trying to just catch everything, try a lot of very small food like normal fish food.

 

[Calappidae]

Very well drawn out and informative!

These traps work well for eunicids, fire worms, bristleworms, brittle stars, and the like as well. Squid I heard is more enticing.. but I don't think it matters. I heard damsels are suckers for these traps as well.

I will note a mantis shrimp should be target fed via tongs first for a bit before trying to catch it with this trap.. reason being they need a little training to a frozen diet sometimes. Eventually they'll smell it and look for it and thats when the trap comes in.

One little feature thats optional is siliconing around the cut rims, as they're usually very sharp and hazardous to fish swimming by/rubbing on it.

 

[Betta132]

Pretty much anything that moves around on the bottom and eats meaty-ish foods can be caught in there. I'd suspect that you could catch a sea cucumber with a big bottle and the right bait.
Damsels are definitely pretty easily caught by a trap that's raised slightly... You just have to find a bottle with a large enough lid opening to let them in.
I didn't know about the mantis feeding thing... Do you suppose just tossing the food in near its hiding place would work? I don't have one to catch, I'm just collecting information. I'd edit the first post with this stuff, if I could.
The silicone is a good idea, but the only way to get the critters out to tug the top out and tip the caught thing out. I suppose accurate silicone could be pried away...

 

[Calappidae]

Pretty much anything that moves around on the bottom and eats meaty-ish foods can be caught in there. I'd suspect that you could catch a sea cucumber with a big bottle and the right bait.
Damsels are definitely pretty easily caught by a trap that's raised slightly... You just have to find a bottle with a large enough lid opening to let them in.
I didn't know about the mantis feeding thing... Do you suppose just tossing the food in near its hiding place would work? I don't have one to catch, I'm just collecting information. I'd edit the first post with this stuff, if I could.
The silicone is a good idea, but the only way to get the critters out to tug the top out and tip the caught thing out. I suppose accurate silicone could be pried away...

Silicone the rims BEFORE connecting the pieces together.. unless there is a gap inbetween.. maybe rubberband netting around it like cheeseclothe, and cut out a hole in the middle to crawl into? Just trying to think of some kind of remedy for the sharp edges..

Putting krill or whatever on a plastic fork and waving it infront of the stomatopods opening would probably trigger it. My O. scyllarus and N. wennerae take krill out of my hand (do not try at home).

 

[Betta132]

The hole-in-cheesecloth thing would work, if you had some kind of ramp out, but the shrimp might climb. With the funnel shape, they run into the little underspace thing and get confused, they pretty much don't ever rear up to reach the hole out.

 

[guric1van]

Does the bottle need to be standing up, or lying on the bed?

 

[Calappidae]

Does the bottle need to be standing up, or lying on the bed?

Laying so they crawl in it.

 

[Betta132]

If you have a large one, you can set it up on the rockwork to catch fish. They should always be more or less laying down, yes.
Interestingly, imbedding one of these vertically in the ground will catch bugs of most kinds.

 

[guric1van]

Do you have to keep adding fresh food in, or can u leave the uneaten food for several days?

 

[Betta132]

Depends on the food and what you're trying to catch. If it's a small amount of food and the target is a scavenger, then I'd say it's fine to leave it for a few days. The scent should draw in those scavengers. It'll work on bristleworms, snails, crabs, and probably shrimp. Might work on mantis shrimps. I don't know what it'll do with fish...

 

[Count Percula]

I'm trying to lure a couple of small blue Damsels with a water bottle with fresh Krill in it. It's been about 8 hours and no luck yet. It would be great if I didn't have to tear all my rocks out to get them out of there.

If no luck by tomorrow, maybe I'll sweeten the deal with some dried brine. I'll let everyone know how it goes.

 

[Betta132]

You can try poking small holes in the sides of the bottle to help get the scent out. Also, put it up somewhere they can see it.
You may want to tie a piece of fishing line to it so you can get it out in a hurry. Midwater fish like damsels sometimes get out accidentally with all their flailing, if they end up halfway through the entrance already.

I have determined that this trap is not effective against peacock gudgeons. A peacock gudgeon behaves a lot like a Hector's goby, it hovers around an inch or so above the sand. When I was trying to trap some speedy rasboras in my freshwater tank,t the gudgeon figured it out. She would just calmly swim into the bottle, eat all the food, turn around, and calmly swim right back out of the hole that was set at her level. The only way to catch her in there would be to tie a string to the trap and haul it out the second she went in.