weak individuals in group of Geos

[211303]

I have a group of 6 Geophagus orange head tapajos in my 90g tank. There are 2 male and 4 female. I have kept them for a year now since they arrived at the size of 1.5". The male are growing nicely, with length of 5"+ and showing nice color. However, the problem I now face is that 3 of the female are growing relatively slow. Those three are often chased away by the males once they leave their own territory, so they stay at their corner most of the time.

The first photo shows one of my weak female, which is about 3.5" now, while the second photo shows the same fish with a male. The fish on the top is one of the male, while the bottom one is one of the female. As you can see, it is significantly smaller than the male and is showing the stress bar constantly. I first thought of it as the difference between sex, but one of the female, which is a fixed partner of a male, grow quite nicely and is not chased by the males (apparently with the protection of one of the male).

This picture shows three fish. The first from right is a weaker female, while the second fish is a stronger female. The fish at the back is a male. As you can see, there are a large size difference.

My questions are as follow:
1. Judging from the photo, do you think my weaker female is stressed out?

2. If so, do you think the reduced growth rate and color is a result of the stress?

3. If there is stress, the only source would be the aggression from the males. Is there anything I could do with it? I would prefer to reduce the aggression level of the males or reduce their territory size if it can be done.

 

[neutrino]

I've bred them and raised mutliple generations. Having some be smaller and slower growing is normal ime. So is some chasing and fussing in a group. Doesn't mean anything is wrong with the smaller ones. In your bottom photo, the fish fartherst right looks fat and healthy, just not welcome in the inner circle of what looks like a pair or future pair. Neither wants the interference with their agenda as a pair. More dominant individuals, or especially pairs, will claim favored spots in the tank, often potentially favored spawning sites.

It's common to hear that geos like to be in groups, which they do, but more so when they're young ime. As they reach maturity and pair up they're more interested in their agenda as a pair than being in a group. At this point the orange heads can be in a group or not, it's not really their concern. So you'll see pairs pushing other individuals around, extra females fussing with each other, etc. The orange heads are like a lot of other species, to get pairs it's good to start with a group, but once you get pairs, they don't need a group anymore. You can still keep the group, but their interaction or agenda is now more pair focused more than group focused... so, to an extent their need to be in groups can be overstated imo. They like to grow up in groups, but as adult pairs they don't need to be in a group at all ime.

Yours are looking good btw.

 

[neutrino]

btw... this is where the theory some have that breeding stunts growth doesn't always hold up ime. Lot of times you grow out a large enough group and it's the bigger, stronger, presumably genetically supeiror fish that pair up and start breeding while some of the smallish fish in that generation continue to grow slower and stay smaller despite not becoming the breeders in the group.

 

[211303]

Thank you for your reply. So, I guess it is normal for them to behave so. Will those smaller individuals eventually grow, or they would remain stunt?

 

[Dis]

They should grow fine it will just take longer

 

[neutrino]

They don't always all end up the same size, in fact when you raise enough of them they typically don't. Smaller doesn't have to mean stunted, which is failing to reach their natural growth potential. Some may just be genetically programmed to be a bit smaller than average, some genetically larger than average. It's similar with many species that I've bred, you'll get a few of what I call 'super fish', larger than average, exceptional color, etc. and a few smaller than average. Then again, you don't always know what an individual will eventually turn into. You can get some early bloomers and you can get some late bloomers. Had a group of pigeon blood discus once, the runt of the group started out with almost no color at all but eventually became a big beauty, biggest in the group. Just took him a couple of years.

So you don't always know, individual fish can just be different, different growth rates, different adult size, etc. Probably the most consistent fish I bred were Z rocks lithobates, males almost always grew to 5.5 inches and not much more, 6 max. Most other species I've bred there's been some variation, some more than others. For me orange head males have varied from 6-ish to over 7 inches, females smaller with similar variation.