[cdntanks]

If anyone is looking for really interesting fish that make a good social group, I'd have to say the Mormyridae are worth checking out. I recently obtained six Campylomormyrus rhynchophorus and these guys are great for watching and listening.

Campylomormyrus rhynchophorus

They need some space, meaning bottom of the tank area, so they can spread out a bit when necessary. I've found they will tussle a bit to establish some intra-group relationships but once settled they will gather together at various times and appear to "discuss" stuff, see below.

A really cool thing with Mormyrids is their weakly electric fields produced by a series of modified muscle cells along the body. These fields, called Electric Organ Discharges (EODs), are modulated rapidly in amplitude and rate and used in communication--if you look, there is quite a bit of research literature out there on the topic.

I obtained one of those inexpensive amplifier kits and hooked up a couple of phone wires as electrodes in the tank, using a 9-volt battery and a small speaker you can listen in on the action. Using the amp, you don't need to actually see the fish, you can hear them from the next room.

https://www.canakit.com/4w-amplifier-with-microphone-pre-amp-kit-ck151-uk151.html

I'll have to try and get some video/audio of my bunch, however in the mean time you can check out the Campy cam at:

<i>Campylomormyrus</i> cam | Mormyridae - African weakly electric fishes

for an idea of what you will hear.

 

[Axelrodi202]

Very neat. How are they with plants - do they disrupt the scape at all?

 

[cdntanks]

The tank they currently occupy is lightly planted as it's my quarantine tank. Mostly PFS, a few rocks and a number of 2-inch ABS pipes bound together with zip ties and some attached Microsorum. This species, and I'd assume Gnathonemus petersii, are not really built to do heavy rooting around as their snouts are somewhat delicate.

They like poking down into the PFS for live blackworms. When they find one they do a quick shift into reverse and pull it back out of the sand into free water--kind of like a spaghetti noodle--then the worm gets sucked into the snout real quick. If they were on land I imagine you'd hear a loud slurping as the worm disappears !

I'm quite sure a bunch of these fish would be very easy on most planted tanks. As they roam around, the snouts do go into just about any crevice and hole on the route, but not in a heavyweight, intrusive manner. Occasionally one of them will swim into a bunch of floating Water Sprite and sort of "rest" in the roots and branches until someone else comes along and buzzes them.

When they first arrived I did a 7-day praziquantel (Prazipro) treatment for worms which seemed to work well, while providing regular feeds of live blackworms.

Eventually these fish will go into a large (~200g) African biotope I'm building.

 

[GrampsGrunge]

Christmas tree lighting controlled by PWM of a Brienomyrus brachyistius in a tank at Michigan State University.

https://www.youtube.com/watch?v=K406K_VK2JY