ZebraPleco.com • The complete Hypancistrus zebra resource

Hi all, just want ask... few months ago, i bought 7 pieces 4-5cm L46, all keep in 1 tank... now 4 L46 grow till very big n fat around 7cm...but some still very small around 5-6cm but still very fat too....... is it normal??? thanks...

IMO Yes- this is typical of many fish kept in a group in an aquarium. Some will always seem to be smaller and a few will be bigger. I think part may be due to genetics but even more is due to the group dynamic.

Remember when one puts a bunch of fish into a confined space competition for food is a major issue. The most aggressive fish will get the most to eat. Those which are not such good competitors will get less. But I see more to it than this. Some fish will actually eat less, imo, and remain smaller and thus be less perceived as a competitive threat to others. Its almost a form of defense against having to fight for the food.

I first noticed this phenomenon with baby bn. Some would spurt ahead while others grew much more slowly. I always send out the biggest fish first which meant the "runts" would remain. What I noticed was once the biggest fish were gone, the smaller ones would put on a growth spurt and catch up, I have since noticed the same thing happening with other species including my zebras.

thanks so much for the reply!!! so u mean its better get those big 1 out to another tank...if not those small one will keep remain small... keep seperately...right???

sorry my english not that good ahaha...

Over time that is a good idea. I tend to be an over stocker and will more often have to sell or trade out fish rather than just keep spreading them out. However, If you can move the larger fry/juvies to a new tank, you should definitely see some growth from the runts left behind.

Hi Jaredkuo

As TTA says, seperating them is a good idea. If however you do not have the space or an extra couple of tanks at present, try moving the tank furniture around so that the food can collect in different areas. Also, split the feeding into different times, i.e. feed half as much, twice as often. You will find the larger fish get the initial supply of food first time round and are less aggressive during the second feed.

Rob

i just split my 2.5 foot tank into 2 and seperate them.... 4 bigger at left side, 3 thiner at right side.... yesterday i put 3 hikari carnivous small pellet at both side... morning wake up left side all gone..but right side still can 3 perfect shape pellet..... mean those 3 thiner didn eat..sigh.......