Back to Back Issues Page
The Goldfish Gazette, Issue #012 -- How To Cull Goldfish Fry
December 31, 2014

Goldfish Care Tips and Guidelines

A Free Monthly Resource For Goldfish Enthusiasts
December 2014
Issue #012

In this issue
How to cull goldfish fry
What's new on the Website

Culling goldfish young early and often is the secret to having a pond or aquarium full of prize winning fish.

How To cull Goldfish Fry

After you have had a successful spawning, a few days later you have a problem...hundreds if not thousands of tiny mouths to feed.

It isn't long before it dawns on you that unless you are a commercial operation, there is no way you can raise this number of fry.

If you only have room for a few fish from the spawn, they may as well be the best.

Culling lets you choose what fry are worth keeping, and to discard what is not worth the effort and expense of raising. If you let nature decide, I can promise you that the best fry will not be the ones that survive.

Frequent Early Culling Is Key

Frequent early culling of the fry serves two purposes:

1. It reduces the spawn size to manageable numbers quickly

2. It starts the process of selecting only the very best fry to grow to adults.

Culling fry isn't hard, just time consuming. It takes me about 6 hours to go through 1,500 fry for their first cull. And I usually have a helper!

Goldfish Standards Set The Benchmark

The process of culling is based on a Goldfish Standard that the fry should follow. Any fry that don't follow the standard closely enough are discarded. As an example, if the standard requires two evenly developed tail fins, any fry that have one, or the tail fins are uneven or deformed are discarded.

All goldfish varieties look the same when very young, so culling is done at frequent intervals as different features of the variety start to appear. Twin caudal fins are the first feature to appear.

The website page Goldfish Culling uses Water Bubble Eyes as an example of what to look for when culling fry.

Goldfish Culling Rules

For this E-zine, I want to cover a few important rules I follow that make the process of culling safer for the fry and more efficient.

1. I keep up to 1,500 fry in a 15 gallon aquarium for the week following their first meal. They are then culled for two caudal fins.

2. I always aim to halve the number of fry at each weekly cull so after 5 culls 1,500 fry become 50.

3. Watch water temperatures. Over many hours of culling, water temperatures can rise, especially in small containers being used to hold culled fry. I always start culling in the morning for this reason.

4. Don't overcrowd the fry for too long. The fry do need to be in small containers for culling, but keep refreshing their water or move processed fry back to their aquarium regularly.

Disposing Of Culled Fry

A question often asked is what to do with the culled fry.

Unfortunately the successful Goldfish breeder does create the problem of disposing of unwanted fry. The breeder knows it is impossible to keep all the fry from a spawn, because very few would grow to adults.
The breeder's primary responsibility is to give the 6-12 highest quality fish the best possible conditions.

I dispose of fry in two ways:
Fry from the first cull are euthanized by using boiling water. I euthanize these fry because they are poor examples of the breed, and it doesn't help to raise goldfish standards by having these fish in the market place.

I tend to have no trouble selling surplus fry from later culls to people who grow them on.
I mention in the advert that they have already been culled for double caudal fins, so this makes them more valuable to the buyer.

I am happy to have these fish find there way into pet shops because they should follow the goldfish standard reasonably closely.

To read more on Goldfish culling and standards click here...

What's New On The Website

Goldfish Standards

Fry culling is all about following the ideal standard as closely as possible for the variety of Goldfish you have bred.
I have updated the page on Goldfish Standards and it is a good place to start before even attempting to breed your goldfish.

Read more…

Comments? Ideas? Feedback? I'd love to hear from you. Just reply to this e-zine and tell me what you think, or what topics you want covered.

Next Month’s Topic

Goldfish growth rates.

Back to Back Issues Page