Taking Young, Record Keeping & Culling. by Tom Allen

Taking Young 

The most successful guppy breeders all follow a common practice when taking young…they isolate the pregnant female in a small nursery tank (along with some floating plants or some other type of cover) and allow her to drop her young without the interference of other guppies.  Once it is determined that she is finished, the female can be returned to her breeding tank or disposed of.  Keeping all the young from the same dropping together during their growth period (say up to 6 months) allows you to compare males/females against one another making it easier to select the stunted or mis-colored males and eliminate them from any future breeding setup.

Those of you who choose to participate in IFGA shows on a regular basis will need to have fish available whenever a show is scheduled (typically, April through October/November).  To assure that you have show-quality guppies when you need them, it is imperative that you schedule when you take young.  Let me cite an example of a simple scheduling plan.  Let’s assume that there are shows scheduled for April 1st, May 15th, July 30th and the Annual show on October 1st.  Let’s also assume that you know that your Blues take 6 months to grow into show prime.  Wouldn’t it be great if you could have a full dropping come into prime at the exact time each show is scheduled?  If you want fish for April 1st, you have to take a dropping on October 1st of the prior year (6 months growth cycle).  You would take your second dropping on November 15th, third dropping on February 1st.  Taking a dropping on April 1st should set you up for the Annual show later in the year.  Now, it is altogether possible that your show fish will live beyond 1 show but you shouldn’t depend on it.  There is no worse feeling than to lose a class championship because you didn’t have enough good males available for the shows.   

Remember, no breeder can possibly keep all the young that guppies can produce which is why they got the nicknamed the “millions” fish.  Keep in mind that “the best carpenter is not the one with the biggest pile of sawdust under the tablesaw!”



Think about checking young from an outcross you made earlier, say 4 months into their growth cycle, and seeing super sized and super colored fish.  You’ve decided that these are guppies that, in your mind, are every bit as good in quality as those you’ve seen win in IFGA Best-of-Show competition.  Wouldn’t it be a shame, then,  if you could not recreate the outcross because you couldn’t remember which male and which female were the parents of the potential BOS young?  Since some of you are just starting out with guppies, you may not see this as a problem in your breeding program.  However, as you accumulate droppings of gups and, particularly, when you maintain multiple lines of a color strain, it would be great if you could reproduce, time and again, the outcross which produced these super gups.  Every breeder keeps info at differing detail levels so you will have to choose “how much” and “what” information you need to keep for your breeding program.  Here are some suggestions:

Dropping Number – a number, assigned to each dropping or each new fish/trio, which   can be written on a tank with corresponding background information in a strain           folder.  The dropping number is like your SSN…it’s simply a pointer to more   detailed information held somewhere else.

Color Strain Code – a 2 or 3 character code which highlights the color strain (ALB,  PUR, GRN, HBP, etc.).  If you want, you can also add a 1-digit numerical value to highlight which line of the strain these fish represent (ALB1, ALB2, etc.)

Date acquired – date of birth for a dropping or date of acquisition for a new trio

Crossing information – Color strain codes & Dropping numbers of fish crossed

Genetic background – any pertinent information about the genetics of the fish (i.e. Greens   originally gotten from Lach, etc.)

Generation code – P-0 (parent),  F-1 (first filial generation),  F-2 (second gen),  etc.

Strain description – possibly tied in with Genetic Background since it could help you in making better breeding choices in the future (good size, short dorsals, poor            caudal color, etc.)



If there is any segment of our hobby that often gets overlooked, it is culling.  Culling is the science (art??) of keeping only those guppies that will be used as future breeders or those that will be grown out to be entered in future IFGA (or local) shows.  There are breeders who do not cull because they cannot stomach disposing of a fish.    Typically they raise “mountains” of mediocre fish and find themselves without quality entries whenever good fish are needed to enter into shows.  Obviously, this is not a habit that is encouraged.  If you have a problem of disposing of culls, set up a cull tank and let them live out their lives in this environment.  Better yet, find a shop that will buy, trade or just take your culls and move them out whenever you get a bag full.   

The key to successful culling is to keep an entire dropping of young together as they age and grow.  In this way, you can more easily determine which of the fry just don’t meet the breeding standard that you are trying to establish.  First to go should be guppies that are deformed.  Often you can find another hobbyist who has an Oscar that will be grateful to get your culls.  If you are breeding for males, there will be fish in each dropping that don’t quite match up to the color criteria that you have set for your show fish.  These are often saleable or tradeable at your local fish shop.  Since many droppings contain 50% males and 50% females, you can easily reduce the number of females and allow your males to reach their full potential with more tank space and food.