The Marina 3 in 1 Floating Breeding Trap is an in tank isolation box usually used to keep fish fry safe.
This trap has a V-insert. This product is ideal for breeding live-bearers. The idea is that you can place a pregnant fish in the trap above the insert and newly-born fry fall through and away from the mother to safety. Once the mother has given birth you can put her back into the main aquarium and take out the V-insert to give the fry more swimming space. The trap can support a small amount of loose aquarium plant or plastic plant just to give the young fish somewhere to hide.
This trap can also be a useful tool to have handy for any aquarium because it can be used to keep wounded fish safe. Tropical fish tend to pick on weaker fish. This trap can temporarily protect a wounded fish until you are able to either treat it successfully or in the case of a bully in the tank perhaps re-home a problem fish. For this type of usage you do not need to use the V-insert.
For a marine tanks we have used traps like these before when we’ve found pests like Teddy Bear Crabs or Mantis Shrimps. Using the floating breeding trap we were able to safely re-home the crab into a non-coral tank or the Mantis into a non invertebrate tank. Pests like this often only come out at night. That’s why having something like this can be handy because you can catch it if you see it in the late evening, and then re-home it the following day.
The trap has small slits in the bottom to allow water to flow through in order to keep the water as high quality as the aquarium. Is is also supplied with a lid. On the sides there are two air pockets which allow the trap to float at the surface of the tank.