As important as it is to note the successes in fish keeping, it is also important to note the trials and challenges and to learn from them. Learning from challenges and getting passed them is not the same as failure. It's only failure if you give up! A famous quote from Thomas Edison (the guy who designed the electric light bulb) puts this in perspective. Edison said "I have not failed, I have just found 10,000 ways not to make a light bulb." Edison's continuous innovations as a result of the obstacles he faced led to the creation of the electric light bulbs we have in our homes today.
In raising Melanotaenia Parva, I followed a very similar methodology to that of raising Meltanotaenia Picta (please see my previous blog), however there were some notable changes from the methodology that I believe cost me. So much of rainbowfish fish keeping seems to boil down to risk management, and risk management is especially important during the first 2 weeks in the lives of newly hatched fry. During this time, their survival hangs in the balance, and they are very sensitive to changes in their environment. It is worth noting, that of 20 eggs, only 12 Parva fry hatched, and only 3 fry were successfully raised. Such low survival rates has forced my to analyse where I went wrong, so that I do not repeat the same mistakes again. I do not believe in luck, but I do believe that there were certain ways in which I failed to manage risk effectively, and that it was these mistakes that resulted in higher than expected mortality rates. The risks I have identified are as follows:
1) Having limited resources (in terms of spare tanks, heaters, filters etc) as most new fish keepers do, I decided to mount a fry net on the side of my tank to raise my Parva fry in. As per my blog on 'Raising Melanotaenia Picta,' this has a number of notable advantages and is not in itself a bad idea, however, I also had 40+ 6-8 week old Melanotaenia Picta growing in the same tank. Thus, the bio load in terms of food waste, was quite high as was fish excretion. The proper way to manage this risk would have been to start off with a tank dedicated to raising the Melanotaenia Parva fry only. Thus the issue with bio load would have been greatly reduced.
2) In order to deal with a high bio load, regular water changes were required along with a good vacuuming regime. I ran into two different problems here:
a) I performed 20 percent water changes every two days to ensure the water was kept free of ammonia, nitrites and to ensure that nitrates were low, however, these water changes were performed during the winter. I added tap safe to tap water to rid of chemicals such as chlorine, however, I failed to take significant enough cognisance of the tap water temperature. Whilst 6-8 week old Melanotaenia Picta fry were hardy enough to deal with a drop in water temperature of a few degrees, it is entirely plausible that the few day old Melanotaenia Parva fry were not. It is my belief that this factor alone could have contributed the most to the high mortality rates. In this instance, I should have ensured the tap water was left at room temperature for at least 24 hours. This would have significantly raised the water's temperature, and would have made it less likely to shock young fry.
b) The fish tank itself was planted with a Manado substrate. This made is difficult to vacuum effectively as I did not wish to continuously vacuum away the substrate. This led to an explosion of 'Planaria Worms' in the tank. Whilst the worms themselves are no harm to fish, they are evidence of too much detritus in the substrate. As a result of this experience, I either do not use a substrate when raising fry (glass bottom only), or, I use a course gravel substrate which is easy to vacuum.
3) As per my previous blog 'Raising Melanotaenia Picta,' I also put Java Moss in the fry net, so that the fry had somewhere to hide, and so that they had some micro fauna to feed on following hatching. It is a possibility that there could have been something in the Java Moss that preyed on either the eggs and / or fry, though I have no idea what. I did notice that there were up to 12 fry at one stage, and that this number gradually reduced over the course of a week or so.
4) The breeder net I used was the finest mesh net I could find on the market, however, It is also a possibility that because the fry are so small when they hatch, that they were able to escape from the breeder net through the mesh, or through a tiny hole somewhere. Any fry that would have escaped from the safety of the net would have been small enough to be consumed by the Melanotaenia Picta growing in the main part of the tank.
Melanotaenia Parva are a stunning fish that had been on my personal wish list a long time, and this contributed to my disappointment with regards the small number of fish I managed to raise. To add further to this disappointment, 100 percent of these fish were females, and so despite my effort, I was still without the beautiful red males. Thankfully though, I was able to purchase a few juveniles from an IRG (International Rainbowfish Group) member, and so I now have a nice group of seven fish, males and females. The fish you see pictured at the top of the page, and in the video below is one of these juveniles (approximately 4cm). Colours will only intensify with age, and these fish will reach 8-10 cm. I intend to try to breed these in the coming months, and will have another crack at raising some Melanotaenia Parva.
In raising Melanotaenia Parva, I followed a very similar methodology to that of raising Meltanotaenia Picta (please see my previous blog), however there were some notable changes from the methodology that I believe cost me. So much of rainbowfish fish keeping seems to boil down to risk management, and risk management is especially important during the first 2 weeks in the lives of newly hatched fry. During this time, their survival hangs in the balance, and they are very sensitive to changes in their environment. It is worth noting, that of 20 eggs, only 12 Parva fry hatched, and only 3 fry were successfully raised. Such low survival rates has forced my to analyse where I went wrong, so that I do not repeat the same mistakes again. I do not believe in luck, but I do believe that there were certain ways in which I failed to manage risk effectively, and that it was these mistakes that resulted in higher than expected mortality rates. The risks I have identified are as follows:
1) Having limited resources (in terms of spare tanks, heaters, filters etc) as most new fish keepers do, I decided to mount a fry net on the side of my tank to raise my Parva fry in. As per my blog on 'Raising Melanotaenia Picta,' this has a number of notable advantages and is not in itself a bad idea, however, I also had 40+ 6-8 week old Melanotaenia Picta growing in the same tank. Thus, the bio load in terms of food waste, was quite high as was fish excretion. The proper way to manage this risk would have been to start off with a tank dedicated to raising the Melanotaenia Parva fry only. Thus the issue with bio load would have been greatly reduced.
2) In order to deal with a high bio load, regular water changes were required along with a good vacuuming regime. I ran into two different problems here:
a) I performed 20 percent water changes every two days to ensure the water was kept free of ammonia, nitrites and to ensure that nitrates were low, however, these water changes were performed during the winter. I added tap safe to tap water to rid of chemicals such as chlorine, however, I failed to take significant enough cognisance of the tap water temperature. Whilst 6-8 week old Melanotaenia Picta fry were hardy enough to deal with a drop in water temperature of a few degrees, it is entirely plausible that the few day old Melanotaenia Parva fry were not. It is my belief that this factor alone could have contributed the most to the high mortality rates. In this instance, I should have ensured the tap water was left at room temperature for at least 24 hours. This would have significantly raised the water's temperature, and would have made it less likely to shock young fry.
b) The fish tank itself was planted with a Manado substrate. This made is difficult to vacuum effectively as I did not wish to continuously vacuum away the substrate. This led to an explosion of 'Planaria Worms' in the tank. Whilst the worms themselves are no harm to fish, they are evidence of too much detritus in the substrate. As a result of this experience, I either do not use a substrate when raising fry (glass bottom only), or, I use a course gravel substrate which is easy to vacuum.
3) As per my previous blog 'Raising Melanotaenia Picta,' I also put Java Moss in the fry net, so that the fry had somewhere to hide, and so that they had some micro fauna to feed on following hatching. It is a possibility that there could have been something in the Java Moss that preyed on either the eggs and / or fry, though I have no idea what. I did notice that there were up to 12 fry at one stage, and that this number gradually reduced over the course of a week or so.
4) The breeder net I used was the finest mesh net I could find on the market, however, It is also a possibility that because the fry are so small when they hatch, that they were able to escape from the breeder net through the mesh, or through a tiny hole somewhere. Any fry that would have escaped from the safety of the net would have been small enough to be consumed by the Melanotaenia Picta growing in the main part of the tank.
Melanotaenia Parva are a stunning fish that had been on my personal wish list a long time, and this contributed to my disappointment with regards the small number of fish I managed to raise. To add further to this disappointment, 100 percent of these fish were females, and so despite my effort, I was still without the beautiful red males. Thankfully though, I was able to purchase a few juveniles from an IRG (International Rainbowfish Group) member, and so I now have a nice group of seven fish, males and females. The fish you see pictured at the top of the page, and in the video below is one of these juveniles (approximately 4cm). Colours will only intensify with age, and these fish will reach 8-10 cm. I intend to try to breed these in the coming months, and will have another crack at raising some Melanotaenia Parva.