The other night when feeding one of my tanks, I noticed a very small (~ 1″), solid black colored cichlid venture out from a little crevice and grab a morsel? I stood there watching in utter amazement. Why? There shouldn’t be any juvenile cichlids or even fry in that tank. It contains no breeding pairs of species…at least I thought. The tank is a 75g community Tanganyikan tank containing leleupis, a male and female Neolamprologus tretocephalus, a lone female Julidichromis marlieri, a lone Eretmodus cyanostictus, two small plecos, some dithers and three adult Altolamprologus calvus (2x male, 1 female).
Could it be a hybrid? Maybe, but unlikely given the occupants. There are only two cichlid species in the tank that are at least 50% black in color – the calvus and the lone marlieri. Even though the lone female marlieri had a mate at one time, he passed a few months ago. Is it possible the juvenile is from her last brood and it has managed to hide all of this time? I thought about that but dismissed it. Not long after the male had passed, I took some their remaining offspring to my LFS. And most of them were larger at that time than the juvenile is now. Julies grow quickly, plus as you can see in the photo above, it contains no striping on the body (only a little on caudal and dorsal fins). If it is a marlieri, it is large enough now to be displaying typical marlieri patterns, which it clearly isn’t nor does it have the Julie body shape.
Also as of a few months ago, I had a breeding pair of Telmatochromis temporalis in that tank. The female produced numerous broods there. In fact, she was so productive, I separated and re-homed both the adults in other tanks I maintain. I’ve seen plenty temporalis fry and juveniles but it just doesn’t look like them. I think the adults have been out of that tank way too long for there to be a lone juvenile holdout. Plus, I’m almost certain it would be much larger by now than the little fella is. I guess it’s possible I missed it.
So what is it? At this point, I have no idea. I took six photos and enlarged them but still can’t tell. The photo at the top of this post was the best of them. In that shot, the juvenile is hovering just above a river rock (covered in algae), which is only about 1″ thick. The large white object in the background is a piece of 3″ PVC. Sadly, you can see how badly scratched the bottom of the tank glass is from the small scratch lines with algae in them.
It has to be a calvus, a marlieri, or a temporalis? Calvus are very slow growers and don’t reach breeding age for quite awhile. Though mine are over three years old, I purchased them as small juveniles (~1.75″). The two males are now nearly 6″, and the female a bit smaller. The juvenile is small but would have to be at least several months old by now. There are no other adult fish in the tank that are black. The color pattern on the tail resembles both calvus and marlieri, but it’s large enough by now to 1) be displaying body patterns of something and 2) if a calvus, I should already see the distinct head shape.
I have never seen any fry from the calvus or even any eggs. If there have been fry, they’ve never made it past fry stage. The tank is loaded with ceramic caves of different sizes, along with some holey rock, some river rock, some large PVC connectors, and plastic plants. These occupy much of the footprint, and the caves are even stacked.
Twice a month I remove 1/2 of the tank’s contents (all caves, rocks, PVC, and plants) in order to thoroughly vacuum the sand though I vacuum the perimeter weekly with water changes. I alternate removing left and right side contents. When I remove the caves, I check inside them pretty closely to ensure they contain no fish. So I have no idea how I would have never seen any eggs. I have never even witnessed any of the adult calvus “protecting” a particular area of the tank. In fact, I’ve never witnessed them being belligerent with any other fish, only each other.
There may well be more than that one offspring in the tank, but given its age, the number of times I’ve removed tank contents, and the fact I’ve only seen that one, I think it’s a lone survivor. Thankfully, I think it’s nearly large enough now to survive. The only tank occupants large enough to eat it are the calvus and the male tret.
If you have any guesses, leave me a comment. Until it gets larger, I’ll just have to continue to speculate. Stay tuned!