Breeding Pseudomugil Gertrudae Aru II
The methods I used are as follows:
1. I set up a dedicated, species only breeding tank (50 Litres) for my Pseudomugil Gertrudae Aru II. The tank was glass bottomed (no substrate was used), and was decorated with a piece of bogwood with a portion of java moss tied to it. Blue Eyes spawn on fine leaved plants such as java moss, and so I used this moss as a medium to focus their attention. I also used a simple sponge filter, air driven and set low so as not to create too much flow / turbulence in the tank.
2. I sourced some Pseudomugil Gertrudae Aru II fish from a couple of different sources within Europe. This is to ensure as far as possible that good genetics are maintained. In total, I had 11 fish, 5 males and 6 females. These make up my breeding group.
3. I maintained steady water parameters - temperature approx 24 C, pH approx 7.2-7.3 and conducted 10 litre water changes every two days. Small, frequent water changes helps maintain good water quality by keeping ammonia, nitrites and nitrates low, but also helps keep the glass base clean. I found that food mess on the bottom of the tanks generally annoyed me because aside from the water quality issues, I felt it looked bad, and I didn't like having to look at it. Temperature wise, these fish will have a lifespan of about 2 years at 24C and an increase in this temperature will almost certainly lead to a decrease in this lifespan.
4. I fed the fish small portions 3-4 times per day. I typically fed them high quality flake foods, decapsulated brine shrimp eggs and occasionally microworms.
5. At first I saw regular spawning activity, lots of sparring between males, and lots of highly active chasing of the females. I would regularly lift out the bog wood and java moss to inspect for eggs, but I rarely found more than 1-2 eggs. Allen (1995) suggests that after a few weeks, one should start to see fry close to the surface of the water. I waited and I watched, but there was no fry. Whilst some hobbyists will say that Gertrudae will not eat their own eggs / fry, others will say it is important to separate them from the adults. I would see fish regularly pick at the java moss and can only assume, that aside from food scraps, the fish were also eating their eggs.
6. In order for the eggs to stand a better chance at survival, I decided to increase the number and size of spawning mops in the tank. This would increase the number of areas the fish could spawn, and I hoped that it would mean that if the Gertrudae wanted to eat their own eggs they would have to work harder to find them. I added another clump of java moss and was rewarded within four hours with 8 eggs, however, any subsequent attempts to find eggs on this piece of moss proved fruitless.
7. I then decided to try out a synthetic mop. The mop was green, and this made it relatively easy to see eggs on it. I positioned the mop with one end of the bog wood, and let it trail down to the aquarium base. it would seem that gertrudae prefer the mop closer to the bottom than the top of the tank, though i would have to do a lot more experimenting before I could determine what the optimum height / way to position the mop is. After leaving it in over night, I was rewarded with about 15-20 eggs. I picked the eggs off the mop gently with my fingers (they are surprisingly robust) and placed a number of them on a single strand of wool (see below) before placing the mop back in the tank. I placed the eggs in a temporary breeding net to allow them to mature or 'eye up.' Again, within a few hours, I picked out 10-15 more eggs on the same mop. Over the next few weeks, I have regularly collected 8-15 eggs per day. With work schedules etc, it's not always possible to pick the mops out at the opportune time, so it's possible that the vast majority are eaten, but still I am happy with my daily egg counts.
I've had experience of raising a number of different types of Rainbowfish, and to be honest, I found these little Blue Eyes to be the easiest of the lot (so far). Anyone who pays a little bit of care and attention will be able to do it. For anyone interested in raising Blue Eyes / Rainbowfish for the first time, I would highly recommend you try these.
My methods are as follows:
1. Once they hatch, the fry will use up their yolk sack within a very short period of time. The fry are incredibly small (see the picture below), and you will find you have to look quite closely at the water surface to be able to see them. Once you see them come to the surface, you will know they are ready to feed. I used Golden Pearls 5-50 micron as an ideal starter food. This is an incredibly fine powder that I just sprinkle on the water surface. They will sit at the top of the water during day light hours certainly for the first few days.
3. Continue to feed with golden pearls 5-50 micron for up to 1-2 weeks. Don't forget that not all fry will hatch at the same time. After about 3 days though you will be able to introduce micro-worm, and when you do, you will notice a real growth spurt in your little fry.
4. With the introduction of micro-worm comes a real increase in the amount of water changes required. The fact is that most of the micro-worm goes uneaten and falls to the bottom. I would typically vacuum my tank every 2 days and do a 10 percent water change. This keeps the water in tip top shape. Whilst these fry are relatively hardy, they do require clean water with low-no levels of ammonia, nitrites or nitrates. As a warning, be really careful when it comes to the vacuuming, as it's really easy to vacuum the fry up with the worms. No matter how hard I try, I still manage to vacuum some of these guys up, but they're pretty hardy, and 90 percent of the time, you can scoop them up out of your bucket and put them back in your tank with no ill effects.
5. Continue to feed regularly and do your water changes. When the time is right, try to introduce them to the decapsulated brine shrimp eggs. This is a great, highly nutritious food, though it can take them a little time to get onto it. When they do, you will once again notice a growth spurt. I still feed my adults on this stuff at least once per day, giving them some high quality ground up flake as well.
6. Repeat step 5 until they are big enough!
Hope you enjoyed the latest post. Check out the short 10 second video below - it's worth it!
Bibliography
Allen, G. R., (1995) Rainbowfishes in Nature and in the Aquarium. Germany. Tetra Verlag.