is culling cherry shrimp necessary?

[kanokoro]

i have a 60ltr tank with only cherries in it, and I don't particularly care about colour grading or breeding for more impressive colours. i love all of my shrimp equally
when I first got them, I thought I'd have to cull them eventually as they'd just breed indefinitely, but I've read in a few different places that they'll stop breeding naturally once they reach capacity for the space they have.
is this true? is it a reliable method? i obviously don't want to kill any of them, but I struggle to believe they'd be able to just stop before the water parameters start to change

 

[Wills]

Its not that they stop breeding but eventually a population levels out based on the amount of food there is, the smaller or weaker ones just dont get enough food and die off... so you don't need to cull them as the only way the numbers will increase, is if they start to decrease naturally through old age or predation (if you keep them with fish that can eat them)

 

[kanokoro]

how does that work if the tank is planted? Its full of java moss and there's a significant amount of algae on parts of the landscape so I feel like the babies could just eat forever lol

 

[Wills]

how does that work if the tank is planted? Its full of java moss and there's a significant amount of algae on parts of the landscape so I feel like the babies could just eat forever lol

There will be a finite amount of food vs shrimp though. Your colony will probably end up in the hundreds which is fine as they put so little strain on the bio load of a tank.

I started nearly a year ago with 20ish Cherries in my 8 gallon and easily over 100 in there now, probably over 200. Like you very heavily planted and scaped, variety of films and algaes in the tank etc.

Wills

 

[BrianK]

If you never cull, there will eventually be no "cherry" shrimp left. They will all be brownish.

 

[seangee]

Somehow they do regulate the population. My group has been going for just over 5 years. I added 10 red rilis to a 57l tank. At times the population has gone well over 200 and then dropped right back. I think I have somewhere around 20 now (its impossible to tell because there are a lot of plants and hiding places.) Mine tend not to breed over winter but right now I have a couple of berried females and several more with prominent saddles so its all about to kick off again.

FWIW every shrimp in the tank after 5 years is a red rili, no wild types. One of my original shrimps had a mismarking which has carried through the generations and I still see it regularly. Since I am not breeding for profit I am happy to let it be. I do have one that is completely clear (transparent). If I get any more I may move these to a separate tank and see if I can get a colony of "glass" cherry shrimp. But I won't be culling, I'll just move any that have red in them back to the original tank.

 

[Essjay]

Mine are all still red after 10 years or so. It's when the colours are mixed that they end up as wild coloured; sticking with just one colour they stay that colour.

 

[emeraldking]

Shrimps can go on and on with reproducing no matter how much space there is left in a tank. Degeneration of color and shape is less present in shrimps than in fish when no new blood is added to the group. And that can go up for years.
Culling is only needed if you want to keep the quality up for specific traits of a shrimp. Even in a healthy group of just one shrimp species, it can happen that there are some that are not intensive colored or not perfectly patterned. That's just normal. But there are also colonies where no degraded colors are present no matter how long possible inbreeding has happened.
With monochrome (one colored) shrimps there's less till none culling needed. But when you're dealing with shrimps that have a pattern on the body, individual shrimps can differ in pattern. And the ones that you just dislike can be culled if you feel up to it.
Once you mix shrimp types, yes the outcome of the new offspring throughout generations can differ a lot. In that case, I don't see the need of culling anyways.

 

[peterwoods]

Actually, you have no choice if you want to maintain your shrimp colony looking as well as it possibly can. Shrimp must be culled. Your prawn colony will have richer colorations and patterns if you kill them. Otherwise, they will return to their wild-type colour.

 

[Essjay]

I have had my shrimp colony for around 10 years and they are still all red. No wild coloured shrimps.

 

[Slaphppy7]

"is culling cherry shrimp necessary?"

No, it is not.

 

[Bpfoto]

I have given some away or sold a few at reduced prices. But mine are still "bloody Marys" after breeding for years.