Short background:
About a year ago I set up a five gallon freshwater tank in my office to give a bit of life to the room. I added five White Cloud minnows over a period of about a month and the tank cycled really well. I must have received a breeding pair as about six weeks later I noticed about 20 or so fry swimming around. I separated them out into a smaller container and about a dozen survived long enough to grow beyond becoming food for the others. I put together a 55 gallon setup to move them all into, and again everything went well here. As it turns out, about a week after moving those to the 55g I saw another batch of fry in the 5g tank that was otherwise empty. Again about a dozen survived and after they were grown enough I moved them into the 55 gallon to join the others.
The problem / question:
Not long after adding this second group I noticed an extreme difference in coloration in the younger ones, particularly their reflective stripe. No exaggeration here, they were so different that my first thought was somehow I got some Neon Tetra young into the five gallon! These younger minnows are much lighter in color with more vivid red and a very strong glow to their stripes. I can only guess that the others diminished slowly over time so that I was never aware of how much they had lost.
Now my question is - is this likely because the older fish naturally lost their appearance over time, being at least a year older.. or is there something about the conditions of the new tank that is affecting them?
Water quality shouldn't be much different.. it came from the same pipes and I used some gravel and filter media from the original tank to seed the new one. Water tests don't show any problems for either tank. The only difference (other than size of course) is that the 55 gallon was made into a community tank, so it is heated to 79 F and has some other species in there, but none of them are aggressive or bully the minnows. Food has been the same across this time, and the new tank has good cover with artificial wood and plants, although the minnows don't really make use of this and school together near the top.
Thoughts?
About a year ago I set up a five gallon freshwater tank in my office to give a bit of life to the room. I added five White Cloud minnows over a period of about a month and the tank cycled really well. I must have received a breeding pair as about six weeks later I noticed about 20 or so fry swimming around. I separated them out into a smaller container and about a dozen survived long enough to grow beyond becoming food for the others. I put together a 55 gallon setup to move them all into, and again everything went well here. As it turns out, about a week after moving those to the 55g I saw another batch of fry in the 5g tank that was otherwise empty. Again about a dozen survived and after they were grown enough I moved them into the 55 gallon to join the others.
The problem / question:
Not long after adding this second group I noticed an extreme difference in coloration in the younger ones, particularly their reflective stripe. No exaggeration here, they were so different that my first thought was somehow I got some Neon Tetra young into the five gallon! These younger minnows are much lighter in color with more vivid red and a very strong glow to their stripes. I can only guess that the others diminished slowly over time so that I was never aware of how much they had lost.
Now my question is - is this likely because the older fish naturally lost their appearance over time, being at least a year older.. or is there something about the conditions of the new tank that is affecting them?
Water quality shouldn't be much different.. it came from the same pipes and I used some gravel and filter media from the original tank to seed the new one. Water tests don't show any problems for either tank. The only difference (other than size of course) is that the 55 gallon was made into a community tank, so it is heated to 79 F and has some other species in there, but none of them are aggressive or bully the minnows. Food has been the same across this time, and the new tank has good cover with artificial wood and plants, although the minnows don't really make use of this and school together near the top.
Thoughts?
