Here are some links to DIY traps for aquarium fish. These traps and many variations have been around for a long time, so it is difficult to credit the original inventor, but I’ve used these websites to influence my designs.

The following website was the result of a search I did on “DIY bristlenose trap”:

http://www.aquariacentral.com/forums/showthread.php?t=229008

Here’s how to make a DIY trap on youtube

http://www.youtube.com/watch?v=IdZDU52sixw&feature=player_embedded#!

This one mentions how to add a line to draw the trap up (I added the line before I saw this website, though):

http://www.aquariumlife.com.au/showthread.php/15565-Guillotine-style-Bristlenose-trap