Carinotetraodon irrubesco
Several years ago, I was intrigued by a unique little puffer that was hard to find, but supposedly not difficult to keep. They are one of the few puffers that can be easily sexed and in turn, they can be bred, much like their relative, the dwarf puffer. These little puffers are known as red tail red eye puffers, or scientifically as Carinotetraodon irrubesco. I set out to keep a trio, two females and a male, to see if I could breed them along the way. I discovered that keeping them was the easy part; it was getting them that would prove to be most difficult.
C. irrubesco stays small, only growing to 2 inches. A ten gallon tank would be sufficient for a single one, however if keeping a small group, a 20 gallon long to 30 gallon would be better. Avoid a twenty gallon high because it does not have as much ground space as the twenty long and could create issues when the puffers are sorting out their territories. For my trio, I decided to keep them in a 20 long and set it up as a planted tank. I planted it heavily using a variety of low to medium-high light plants. I had approximately 4 watts per gallon and used a sugar and yeast CO2 injection system. I also had multiple caves in the tank for the puffers to choose from. I cycled the tank by using existing media from another well established tank that I had at the time. The temperature was set at 78 degrees Fahrenheit with a pH of 7.5. C. irrubesco are not picky about water parameters, as long as those parameters are stable.
Probably the biggest challenge I had in keeping them was actually finding them. While I have many stores to choose from, few carry any real selection of freshwater puffers. Although some stores did special orders, they were unable to find them as well. I finally got a lead from a friend who had seen some at a local store, although they were mixed in with another species, C. lorteti, the red tail puffer. They are very similar to C. irrubesco except they lack the red eye and tend to be more aggressive. I did my best to pick out two females and a male, a ratio that I hoped would be conducive to breeding. I brought them home, acclimated them to the tank and released them. Then I waited and watched.
At first all three puffers were very shy. They only came out if I kept away from the tank and even then they stayed close to cover so that they could disappear quickly if needed. The only thing that they did come out readily for was feeding time. They willingly accepted live blackworms and frozen bloodworms. They also enjoyed snails, most of which had snuck in on the plants. The puffers also received frozen mysis shrimp and live ghost shrimp as food as well. The ghost shrimp were an excellent live food source for two reasons. First, they were really good at cleaning up the scraps the puffers would leave behind, as they tended to be very messy eaters. Second, they were very good at getting away from the puffers and were a real challenge for the puffers to catch. This would keep the puffers engaged and active for hours trying to hunt down the shrimp. I typically fed the trio every day, skipping a day once a week or so.
One interesting note about these puffers is that their teeth do not seem to grow at the same rate as many other puffer species. While they are most likely susceptible to overgrown teeth, I did not have any trouble with tooth growth during the time that I had them with the diet listed above. I would feed them snails often, but more often than not, the puffers would pull them out of the shells rather than crushing them to get to the snail inside. Even still, the mysis shrimp, blackworms and bloodworms and occasional ghost shrimp seemed to provide sufficient crunch to keep their teeth from overgrowing.
As the trio settled in, they finally began to show their natural colors. Unfortunately, I discovered that my puffers were not as they first appeared. Fortunately, they were all C. irrubesco, but instead of getting a male and two females, I had actually gotten three males. Initially I was worried that this situation would lead to fighting between them as they matured. With other fish, keeping multiple males in the same tank can lead to disaster and I figured that the puffers would be no exception. Fortunately though, it seems that they were the exception. Although they did occasionally squabble, for the most part they kept to themselves and there was almost no fighting. I suspect that part of this was because there were no females present for them to fight over, however at this time I have no evidence to support that and would still recommend keeping them in a ratio of one male per 3 or more females to minimize the risk of fighting. Another factor that contributed to the peace in the tank was how it was decorated. The tank was very heavily planted and had multiple caves for the puffers to choose from. When they were out exploring the tank and hunting for food, the puffers could go for long periods without seeing each other and as a result were less likely to fight over territory.
I had originally planned to not have any tankmates in with the puffers. After I had set up the tank and cycled it, I needed something to sustain the cycle until I was able to locate the puffers. I had a multitude of guppies in another tank and so I moved some of them over to the puffers’ tank until I could locate the puffers. Also, because it was a planted tank, I needed something other than snails to help control algae. While snails do a good job, they also happen to be a favorite snack and so they never lasted long in the tank. After giving it some thought and research, I decided to try a small shoal of otocinclus cats. I introduced four in the tank before I had found the puffers so that they had a chance to get comfortable with their surroundings. I finally found and added the puffers not sure how well the tankmates would do. I removed the majority of the guppies, however with the tank being heavily planted, I could not get all of them without destroying the tank. I was surprised to see that for the most part the puffers left the guppies alone. Guppy reproduction halted in the tank though and I suspect that the puffers were picking off the fry shortly after birth. The otocinclus were totally ignored and I never saw the puffers show any interest in them. They seemed to do an excellent job of blending into the plants and at the same time do their job effectively.
The Red Tail Red Eye Puffer is a fun little puffer
Had I been successful in selecting 1 male and 2 females, the next step would have been to attempt to breed them. I had already prepared the tank by placing java moss on top of one of the caves to provide a breeding ground for the puffers. Once they had established their territories and settled down, the next step is to condition them to breed. Live and frozen foods are an excellent way to ensure that the puffers are getting the right nutrition to encourage breeding. A large water change may help to stimulate spawning activities, but more often than not, these puffers will decide on their own when the time is right to spawn. At that point, the male and female will go through a ritual dance and if the female is ready, she will find a safe place to deposit the eggs for the male to fertilize. Java moss or a similar plant is often chosen, though they may spread the eggs in the gravel as well. If the java moss is well established, it will probably have enough life in it to sustain the baby puffers for a week or so after they hatch. Unfortunately, I have not found any detailed information on rearing C. irrubesco however; because of their similarity to C. travancoricus (the dwarf puffer) I would imagine that C. irrubesco fry would follow a similar timeline. For the dwarf puffer, eggs typically hatch out around 5 days after being fertilized. After 2 weeks the fry are typically free swimming and beginning to hunt for food. Good choices for food at this point can include infusoria (which will be present in the java moss), newly hatched brine shrimp, and microworms. While C. irrubesco may differ slightly in the timeline, the fry should do just as well on that diet and may actually be slightly larger overall versus the smaller dwarf puffer.
The red tail red eye puffer is a great choice for the aquarist who is looking for something a little bit different to keep in a smaller aquarium. Their comical ways of swimming and apparent curiosity can provide many hours of enjoyment. For a puffer, they are fairly simple to keep without the hassle of dealing with mixing up salt or brackish water. For an added challenge, they can be sexed and bred, providing even more learning and enjoyment opportunities as the aquarist raises the young.
