Pipefish are closely related to seahorses and pipehorses and as such care is pretty much the same as for them. They are available captive bred and these are generally alot easier to care for than wild caught due to being more resistant to disease, readily accepting dead food rather than live, etc. Unlike seahorses, male pipefish will often fight so it is best to keep one male per tank. Generally it is best to keep them in a species tank but there are a few fish suitable as tankmates (seahorses for instance). Before buying considerable research should be conducted as they aren't your typical danio, etc when it comes to needs, care, housing, etc. If you are still interested in keeping pipefish then just post and I will put up some more detailed info and where you can do further research.