Revisiting an Old Favorite—Aequidens rivulatus, the Green Terror
By David Mentjes, MAS
I have been keeping fish for quite a number of years—dating back to when I was about 5 and had a couple of goldfish. Yes, I had given them names. One I called Cannonball and the other was affectionately called Superman. Even though I knew little about the aquarium hobby back then, I was fortunate to have them each live for longer than 7-8 years. I’m sure that positive experience from my childhood solidified my interest in fish and how to care for them. Along the years, a number of positive experiences stand out.
Approximately 10 years ago, while in college in Champaign/Urbana, Illinois, I had the fortune of coming across a fish called the green terror. Due to their strikingly good looks, I decided that I had to keep them and, with luck, breed them also. I did a little research before getting them from the store (which always seems to be the last thing on my mind when viewing a new fish that I "had" to have). I was able to tell males from females because they are sexually dimorphic. The males tend to have a much brighter green/blue scale color covering almost the entire body intermixed with rows of dark red to brown scales. As with many cichlids, the females tend to be a bit less colorful. In addition, the males have elongated and pointed dorsal and anal fins. The dorsal fins and caudal fins of both sexes tend to be outlined in white to orange to red color. They also both show a brilliant blue to green reticulated pattern on their faces. Back then, I happened to have a 15 gallon tank waiting for inhabitants. They can also become quite large over time—males over 10-12 inches and females a little smaller. They also live up to their common name pretty well. Nevertheless, I picked out a small pair and brought them home. A short time later, they spawned. During the spawning and caring for the eggs afterward, the male’s color intensified and the female became very dark to almost black along most of her entire ventrum. They tend to make excellent parents, especially after the first spawn or two. I have such fond memories of that small pair back then that it was probably inevitable that I would have them again.
As luck, or fate, would have it, I was back to school last fall for a weekend continuing education conference. I had to check out all the old "haunts," including the local fish stores. One store just happened to have some young green terrors. I vowed that if they were still there on my way out of town the next day, I would bring them back with me. I ended up bringing home a very young and small pair. The male was, at approximately 3 ˝ inches, slightly larger than the female. They were quite thin, so I decided to put them in tanks of their own to bulk them up a bit. The tanks happened to be directly next to each other. After just a few short weeks, they both had gotten in better condition and the female was starting to show spawning coloration. I moved the male in with her, and within hours they had spawned. The female kept close watch over the eggs, while the male tried to fend me away as any other intruder. Unfortunately, they ate the entire spawn of approximately 300 as soon as the fry became free-swimming. The male then started to really pick on the female, so again they were separated. Four weeks later they went through all the same rituals and another spawn ensued. I immediately took the male out and put him back in his own tank. I then took the piece of slate containing the eggs and placed it in a 5 ˝ gallon bare tank with a sponge filter. I did not use any antifungal agents in the water, thinking if I lost some eggs to fungus, I would still have more than enough to raise. Sure enough, 3 days after the 300 or so eggs were laid, roughly half of them hatched. Within 9 days they were free swimming and eating baby brine shrimp readily. I don’t think a single one that hatched has died. They seem to be not only prolific (I can hardly imagine how many eggs they’ll lay when they are much larger), but they also seem to be very tolerant of water conditions. I use water from the tap and the tanks are roughly 75 degrees. I don’t pay very close attention to many other water parameters, mainly out of laziness but also because the fish seem to all do very well.
I look forward to getting my big tank up and running again and the green terrors will be among the first inhabitants. I feel very fortunate to have come across one of my all-time favorites at a time I was not expecting to, and it was very rewarding to be able to relive some of the strongest memories I have of this hobby. I have learned to think of not only the newest or most difficult fish that are entering the hobby, but also of those from times past.