Advice Please - Ratio Question

[GlockFu]

I am setting up a new Zebra tank. I have more males then I need so I have the option to set it up as:

1) 1 Male and 2 Females
2) 2 Males and 2 Females

Which male to female ratio do you think would be better and why?

[TwoTankAmin]

2/2. You can potentially have 2 spawns at the same time with this setup.

I have been discusiing this topic on and off with barbie over the past months. I am a believer in a a colony approach while she is quick to point out that all it takes for spawning is one of each sex.

My feeling, not backed up by any scientific studies, is that a group increases the odds of getting spawns as well as multiple spawns at the same time. If the fish are mostly unrelated it also means the chance of getting spawns from different combos is possible.

Consider this- if you have only a single pair, both must be in condition and the mood to spawn. In a colony there should be multiple members ready. Even though the females would all prefer the alpha male, only one will win the prize. Once she does, the alpha male is now occupied. The number two fm, who lost out is still probably ready to spawn and in the mood. She is likely to find an acceptable partner with another male lower down in the pecking order. The same sort of thing could be said about multiple males.

I am also a believer in the idea that more females than males is the better route. Any male can tend eggs, but only females can produce them. So to get the maximum egg output, you need more females.

However, there is a difference between setting up a new group vs trying to add fish to an estanblished one. Lets say you have a group of spawners who have been together for some time. Introducing new fish, even additional females, may very well disrupt the pecking order and result in no spawning at all for hower long it takes to get things resorted out within the group.

All this said, I am still looking to add a couple of new females to my colony. I have lost 3/13 breeders over the past 2.5+ years and have a strong hunch that they were at least 2 females lost- especially the most recent loss over the summer. The spawn rate has dropped this year from the prior two years and I believe it is due to having fewer females in the group.

[GlockFu]

Thanks for the detailed explination.

I was thinking the same thing about having more males in order to have better chances of catching two to pair up so that's why I was thinking 2 and 2 but at the same time, as you also said, I would rather have more females than males which would go against having 2 and 2.

Dilemas dilemas

So we have a vote for 2/2... any other thoughts?

I think I lost a few of my females as well and I think my losses were due to fighting even though most people will say the females do not fight. What caused yours to die?

[TwoTankAmin]

The first I believe swam out the back of an inwall tank when I accidentally overflowed it during a water change. It just vanished, never found a corpse. The next one I found floating one day and it was too far rotted to ID. The third was this year and I found it rotted under a rock at the back of the tank and again no clue.

[Barbie]

Some people say more males gives you more competition and squabbling to keep the females interested. It also diffuses the aggression amongst the boys, instead of on the girls. I have more females than males and no spawning at all, but I DID just discover their heater was releasing low voltage, so that too has been replaced. There isn't a holy grail. I've had pairs I didn't try to work with spawn in tanks where I thought they were "healing" from injuries. I've had big groups sit dormant for more than a year. It just depends on the individual fish, IMO.

Barbie

[GlockFu]

hmmm im thinking doing 2 and 2... I guess?? hehe

or maybe I should throw them all into my 60 gal and make one big group?