Let me begin by stating…I love Lake Tanganyika! While I have not been there (yet!), Lake Tanganyika is, for me, the epitome of diversity, so many species, so many habitats, and so many odd & interesting behaviors! The fish of this ancient lake have evolved to fill seemingly every possible nook and cranny of habitat available. From the surge habitat of the lake shores to the mud floor, in everything from rock caves to empty snail shells to open water, the fish of Lake Tanganyika continue to amaze me.
One of these odd little Tanganyikan gems, Xenotilapia bathyphilus (say it with me, z-n-t-l-p- bth--f-ls) ,is the subject of this writing. Found throughout Lake Tanganyika in deeper water (65-330 feet), Xenotilapia bathyphilus is a monomorphic, maternal mouth brooder. The fact that these fish live in deep water in the so called “mud floor” habitat may explain their flattened jet black oversized eyes. Bigger eyes must come in handy on the dark mud floor, where these fish feed on plankton.
The large black eyes of Xenotilapia bathyphilus remind me of the hieroglyphics found in the tombs of Egyptian pharaohs, the paintings on those walls seem to look out at you with an ancient wisdom. Bathyphilus look out at you in much the same way.
Not a very flashy or particularly colorful fish, bathyphilus does have its moments when feeding and especially when spawning. A vaguely torpedo shaped body, silver in color most of this fishes real color is centered in the dorsal fin. This dorsal contains a subtle neon blue combined with a spectacular orange that intensifies dramatically down the flanks during spawning.
I received my fish (a MFF trio) from a fellow hobbyist as mature wild caught fish, so I have no clue as to how old they were when I brought them home. I do know that I had not planned on getting these little beauties and so was NOT prepared for their arrival.
Upon bringing these fish home all I had available was an empty 20 gallon long tank, so that is where they went .Four weeks later I came across a deal on a forty gallon “breeder” tank and stand complete. Perfect for my little oddities. Plenty of floor space, and significantly deeper than the 20 gallon. To say that the change was a dramatic one would be an understatement as one of the females spit several fry upon landing in the new tank!
This change was followed by the equally dramatic disappointment as the other two fish quickly devoured the majority of fry until Mom caught on and finished of the last two young herself!
It was a bittersweet moment, as I was disappointed but also happy as this proved that I had at least a pair of these fish and I had never known that one of them was holding. If she held once, chances were good she would hold again.
The next time these fish spawned I was able to at least witness a part of the event by accident. The male had excavated a shallow “sandpit” under the sponge filter that helped to filter the tank. The male and one of the females seemed to be taking turns entering under the filter into the spawning pit, one would enter then leave. The other followed. I could not really see what was taking place as the tank light was already out due to its timer, so I only had a small room lamp to illuminate the spawning. The only thing I know for sure is that the next morning I had a female holding a mouthful of eggs. The female held her eggs for exactly eighteen days and then they were gone! I assume she ate them. More disappointment.
However, after another two weeks the other female was holding! I had been very busy at work and was not sure exactly when the fish had spawned this time so with much hand wringing fifteen days after noticing the holding female, I decided to attempt to strip her of the fry. Now this sounds very simple on paper and in retrospect it really is very simple. nonetheless I was very nervous about hurting “Mom”, I had never attempted to get a mouth brooding female to “spit” her fry before and, I must admit. I very nearly lost my nerve. I mean what if I injured or worse killed my female? In the end I guess I was more concerned about losing another batch of fry because I filled a five gallon bucket about halfway with tank water and went about netting “Mom”.
It took me about half an hour to catch her as I was trying to be very careful not to stress her or myself anymore than absolutely necessary, for me because I was worried that clumsy handling of such a delicate fish would result in injury or death for the fish . And for the fish since these fish live at such deep depths they seem to have no clue about the surface and can be world class Olympic jumpers in tanks. (This may be a good time to recommend a very tight fitting lid and few (if any) smooth rocks if you decide to attempt these fish at home).
When I did finally catch her I held “Mom” in the net with wet hands in the net and maneuvered her so that only her head was out of the net. Keeping a firm but not to tight grip on her with my left hand I positioned “Mom” over the bucket and used the index finger of my free hand to try and gently pry open her mouth. She was not having any of it and kept her mouth firmly clamped shut! This entire process had already been going on for at least thirty seconds or so and as I stated I was VERY nervous about harming “Mom” so I decided to abort. I removed my index finger from “Mom’s’ mouth and as soon as I did she spit out a rapid fire stream of fry!! I ended up with nine miniature versions of “Mom”. I was not entirely certain that all the fry had been spit out, but did not want to risk “Mom” anymore so I put her back into the main tank right away. I would estimate the fish was out of the water for less than one minute, but it seemed much longer than that to me. I’m sure she felt the same way!
I initially placed the fry into a five gallon clear Rubbermaid container with a seasoned sponge filter and a “junior heater” from Wal-Mart. I filled the container with water from the main tank (pH about 8.5-9.0 and very hard). The Xeno fry grew quickly on cyclpoeeze, freshly hatched brine shrimp and micro-worms; soon it was time to move them to larger quarters. I decided to house them in a ten gallon tank that contained a few clumps of java moss and a small group of Endlers livebearers that my son had been given at our first MASI meeting. The Xenotilapia fry continued to grow well and the Endlers fry disappeared almost as fast as they were born. It didn’t take long for my son to request that I move my little Tanganyikan jewels from “his” tank! I was amused by the fact that no matter how delicate and docile this species is, they are still more than proficient when it comes to keeping livebearer populations in check. Needless to say the fry continued to grow well and had hit the inch mark in a little under 90 days.
While Xenotilapia Bathyphilus are not suitable for all set-ups they are worth the extra effort in my opinion. I don’t believe they would do well with many other species, but could possibly do well with a school of either Cyprichromis leptosoma or Paracyprichromis nigripinnis. They do however seem to do quite well with Endlers Livebearer’s. But seriously, given a fine sandy bottom, lots of floor space, and calm tank mates that do not compete for the same territory these fish are just plain easy. Xenotilapia bathyphilus are one more reason the fish of Lake Tanganyika are tops on my list!