by Scott Cartwright

I had an 80 gallon tank setup for Tanganyika cichlids but only had a few fish in it. I wanted to keep some shell dwelling cichlids along with some rock dwellers. Club members Erik and Kathy had offered to bring back some fish from the ACA convention so I became the caretaker of eight cute and small Neolamprologus multifaciatus. The tank had at least twenty snail shells in a good sized sandy area ready for their introduction. Erik suggested that I borrow a plastic box that he had built from scrap acrylic in case the fish were terrorized in the large tank despite the ample supply of shells. I placed a couple of the multifaciatus in the tank and they were immediately eyed by the other fish as a couple of tasty snacks. The little fish swam for cover, unfortunately not among the shells, and I quickly decided that this introduction method was not going to work well for them. I grabbed the acrylic box and set it up on top of the rock pile with sand and shells within. Now I had an aquarium within an aquarium and the multifaciatus looked happy in their own private condo.

The new residents made themselves at home by moving the sand and shells around and staking out their territories within the little acrylic box. They wiggled and flared their gills at each other and at any passing fish in the main aquarium that came close to their shell. This arrangement worked fine for a few weeks despite the extra effort required to secure the residents of the acrylic box during a water change. Then one afternoon after work I noticed, to my horror, that a few of the shell dwellers were lying on their sides, others were hidden from view in their shells and the rest were acting very lethargic. They looked like they had been poisoned. Meanwhile, the fish in the main tank were exhibiting completely normal behavior. The acrylic box had numerous small pin holes in its side to allow for some water flow but I had not changed the tank water for a week or two. I had placed the box away from the power filter outflow in order to place it on top of my rock pile. The water must have developed a high level of waste without sufficient water circulation and the fish were suffering. Some of the multifaciatus needed emergency care and I decided that the best thing I could do would be to place the box down on the bottom of the tank in the direct path of the filter outflow and risk possible conflict between the shell dwellers and the rock dwellers. Immediately one of the shell dwellers performed a gruesome death spiral swim out of the box and into the main tank. I have come to assume that once a fish is in such a state that it cannot hold itself steady when it swims, it is breathing its last breaths. The others remained in the box for the time being and much to my relief, the residents of the main tank stayed clear of the box. Over the next few hours, another shell dweller left the box with a dazed swim into oblivion among the dark crevices of the rock pile.

I counted six shell dwellers now, including one very small one that had set up a home under a solitary rock near the acrylic box. The other five went about their business as usual next to their shells and to my amazement they also successfully chased off any of the main tank residents that purposefully or accidentally ventured near the box. This included a Julidochromis transcriptus who was at least five times larger than any of the multifaciatus. The two species would flare gills and mock charge each other from either side of the acrylic walls of the small box but the transcriptus would never attempt to travel up, over and into the box with the shell dwellers. The multifaciatus, in turn, would remain, almost exclusively, within the confines of the box and only venture up in the water column to capture sinking flake food. For the transcriptus, it was as if an invisible barrier had formed from the top of the box walls to the surface of the water.

I kept the multifaciatus in their box on the floor of the tank for a few weeks and they seemed to be doing very well holding their own. The box ended up being too small for some of their taste so they booted one out to the main tank. I then had one shell dweller under a rock next to the box and one that had dug out a little home under the box itself. The transcriptus would still stay out of the acrylic box though it flared its gills and bent its body to appear wider to the fish within the box who would return its threats with gill flares and mock charges of their own. The multifaciatus outside the box were far less confident and they would dash for cover when the transcriptus spotted and chased them. They were bold enough to hang out just outside their hole so they could snatch up bits of sinking or settled food but also dodge back into their hideaway if the big cichlid came swimming by. At this point, I decided that I should try to introduce all of the box residents to the main tank as well as provide additional shells for them in hopes that the two stragglers would be incorporated into the community and find a nice shell to call their own. Before I moved the shell dwellers, I rearranged the rock pile. Now, everyone in the tank could start over and set up a new territory. It appeared that the cichlids would avoid hanging out near the power filter output. (This should really be no surprise since they all come from a lake which has primarily gently flowing if not still water). The shell dwellers adapted to their new home outside of the box, even though their shells were directly below the filter output. The other fish, including the transcriptus, kept their distance.

Several weeks later, we finally finished the basement room and so it was time to move the fish tanks. All the fish seemed to be in good shape for the move. We removed all the rocks, captured and placed the fish in a bucket, drained all the water and then retrieved some help to bring the stand, tank and hood downstairs. Several hours later the tank was up and running. This time I placed the rocks under the power filter and the shells at the opposite end of the tank. Even though, this placement seemed to suit the fish better, three or four weeks later I was down from six to only two multifaciatus! These two fish had also moved a handful of shells together on the tank bottom and had excavated the sand underneath down to the acrylic tank bottom. It appeared that the two had paired off and eliminated the four unwelcome guests.

A few weeks went by and then I noticed three tiny fish swimming among the shells near the bottom of the tank. They were about 1 to 2 mm long when I first spotted them and they did not stray far from the cover of a shell. Meanwhile mom and dad were fearlessly keeping the rest of the tank inhabitants away from their little cluster of shells. With that, I embarked on a daily feeding regimen of frozen baby brine shrimp deposited via a turkey baster over the collection of shells. The babies grew slowly but appeared to be in good health and the parents easily drove off the other fish in the tank with one exception. A Neolamprologus tretocephalus was exerting a little too much free will near the shells and the parents had to work very hard to persuade the lout to swim elsewhere. The tretocephalus seemed to be gaining confidence and I could only imagine the parents were becoming more and more stressed, as was I. The three babies continued to grow but I had enough of the bully. I considered taking it back to the store but it was in fact a very nice looking fish so I purchased a spawning cage instead and prepared for a major effort to capture the beast. With some help I managed to corner and capture him. I hung the cage, composed of a fine mesh net over a plastic box frame, into the tank, placed the ruffian within and breathed a sigh of relief.

Everyone in the tank is doing well now; the babies are still growing, the tretocephalus is still confined to his cell until I set up another tank for him; and the parents are continuing to spawn.