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Old 04/06/2010, 06:28 PM   #9
The Hardy Mongolian Pony
Koshmar's Avatar
Join Date: Nov 2008
Location: Dallas, Texas
Posts: 1,372

9. Take the two ends of the fishing line and thread them through those two holes at the entryway you made with the thumb-tac. See the length of the line in the picture. Make sure the meat is roughly in the middle of the box and cut off the excess ends of the fishing line.

10. You may want to wash the trap off with water before this step. Put the top of the tupperware box on securely and push the trap down into your tank's bottom. Take a light rock and set it on top of the trap.

11. Put your gate into the slit at the top. Push the ends of the fishing line into the box until they almost come out the other side. Make sure the gate doesn't pull the lines out prematurely. (yeah I know interesting wording there right) (See pictures).

12. Just watch the trap for a minute and make sure it looks like the pictures before just walking off. Once everything looks right, you're good to go!

So how do I know this works?

Don't worry she was released within a few minutes and she got that whole big krill for all her work.

I must admit my first one didn't work so I had to keep revising it. I also encountered many problems and found solutions which will help you in creating your own trap. So here's a few tips:

Buoyancy is a major problem with the gate mechanism. The gate must be light enough for the line to support its weight but heavy enough to actually fall. It looks fine and works great outside of a tank but when you put it in water you'll find a lot of things change. It's a simple case of "it worked great on paper". Make the proper corrections by adding weight using rock rubble or something of the nature tied to the top of the gate.

Another issue is the trip system. One of two things can mess up; the mantis can, and I kid you not, untie the knot. Yes, that's right. It happened to me, which is why I strongly suggest double knoting the bait. They don't try to untie it first off, instead they rush at the bait which is another reason to keep the line short. If the line is kept short then the mantis will trigger the gate fall quickly. The other issue is the friction of the line against the hole edges. Try making the holes slightly larger than the diameter of the line, create an easy tripping mechanism but not so easy that the weight of the gate triggers itself. You can also fray the line at the tips somewhat to make angled ends. Also make sure the bait is roughly in the middle of the container or slightly further from the entrance. Do not put the bait at the very end because the line will not come out and trip the gate mechanism.

Putting gravel at the bottom of the trap is also a good idea for buoyancy countering, though the rock works well. I also found out that mantis shrimp have a very difficult time with plastics and finding a way out of a CLEAR container. They don't always go for the entrance at first, nor do they immediately know they are trapped. Sometimes my N. wennerae would freak out even though the gate hadn't come down at all because she couldn't find a way out easily. She still came back though and was trapped.

I made this trap right infront of both my mantis shrimp so even though they are intelligent, they aren't ridiculously intelligent like I was afraid of. The point is that they can still be trapped even if they watch you make the it. Currently I'm working on finding out their learning curve by reintroducing the trap during each feeding. I want to see how long it takes her before she figures out to avoid the trap even when there is food. A little experiment I guess you could say. I'll post those results someday along with how my large 3 1/2 inch G. chiragra (Chet) fares against the trap. Just to let you know the N. wennerae (little buddy Dallas) is aprox. 2 inches. I haven't tried making one for a peacock yet so we'll see about that later.

Last thing: before you try the trap out I suggest posting some pics of your's for me to take a look at that way you don't scare the little guy before you can actually catch it. Feel free to PM me or post your comments or suggestions. I want to try and make this thing even better.

All Day I Dream About Stomatopods

Last edited by Koshmar; 04/06/2010 at 06:43 PM.
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