Line Breeding Explained
by Stephen Neil Kwartler
Reprinted from an article I wrote of the IFGA Bulletin several years ago
The past several days I have been looking over some articles that have appeared in our publication over the past few years. Most of the material is of great value to the guppy hobbyist and breeder. Techniques regarding the development of different strains are abundant. Somehow the author then mentions the introducing of other strains to improve the line or to create variations and hybrids. While this information is valued by the advanced breeder, those struggling to maintain a strain become confused. I receive many letters and phone calls because a breeder had read he can cross his blues with reds to improve his strain. Now I admit that making a cross when necessary can improve a strain, but this is not good advice to the novice, or someone working with limited tank space. Within a short time they become impatient and loose interest. They start to feel they cannot breed to their own expectations. I will try to clear up some of the confusion in this article. I would also like to see some feedback with replies from other breeders. Just write down some of your thoughts and send it along to the Editor. He will be happy to give you some space in this publication. By sharing your experiences with everyone a better understanding of what other breeders are doing can shed some light on the hobby.
I probably maintain too many strains and too many tanks. But I have always tried to follow the same principals when it comes to a breeding program. My basic strains are the result of linebreeding for many years. Remember that accurate record keeping is a must in any breeding program. Let us assume you have just received your first breeding trio or pair of show guppies. The best size tank will be one that is small like a two and a half or a five gallon. If all goes well within a few weeks your females should start to drop young. Try to raise each brood in a separate tank.. Proper feeding which should include baby brine shrimp, along with weekly water changes will help the young grow to their potential. When the young are about three to four weeks old you should remove several of the better females and keep them virgin for the next few months. From the remaining young you can cull out the unwanted males and some females. I usually leave a few females in with my males to keep them chasing.
Within a few months you should have several tanks of juveniles of various ages. As the young mature culling should be a daily practice.. Culling is a way to discard runts and other lesser fish. Now it is time to select new breeders. I suggest picking one or two males from the same brood. If you are fortunate to have males that are similiar, then use the two male method. Next we will be selecting females. I recommend picking similiar looking sisters from the same line , but not the same litter that the males came from. If you have at least three available tanks for your new breeders, try setting up two parallel breeding tanks. In the third tank you may set up a male and several females that are brother and sisters and inbreed them. Some knowledge is required to select the right fish for breeders. A good strong peduncle as well as tail and body shape is equally important as color or pattern. Remember that the amount of breeders you set up will force you to have available the necessary tanks to raise all the future offspring. A simple way to label your breeders is to assign a number to each breeding tank. All young born from setup #1 will carry that number as well as the date they were born. This helps retain the identity of every litter. Label every litter/drop with the day they are born with the associated this will help you trace back every future drop to the proper parents. If you are not prepared to keep all litters separate, you will not be able to follow this method. Once your breeders are selected deciding what to do with the remaining fish can become a trying decision. . Perhaps you will be able to sell them to a local pet shop. This helps to free up tank space. If you intend to show some fish, then you will need a few tanks just to raise them to show size.
Inbreed brothers to their sisters from group A and group B separately. By doing this you will create two related parallel lines. When the next crop from your new breeders comes of age repeat the same procedure again. Hopefully a good percentage of your offspring are as good if not better than what you started with. After breeding for three generations of this type you will make a change. In addition to setting up your new group from A and B, you will now breed group A to group B. Select a male from group A and several females from group B and put hem together. You may also put group B males with group A females. We will call this a back cross. From the resulting offspring you will repeat the original breeding setup you began with group A and B. Remember the sibling breeders you set up when we first started, well we can now introduce them back into our line bred groups. Make one cross into the group from the inbred line, and call all resulting fry by a new group number.
Hopefully you will be seeing an improvement in your strain by this time. All this can be accomplish without seeking or introducing new stock into your strain. Many variations can be added to this type of line breeding. I have maintained most of my lines with this method. Once you have acquired an understanding of what it takes to maintain a pure strain, you can rise from the ranks of the novice and become an experienced guppy breeder.
I probably maintain too many strains and too many tanks. But I have always tried to follow the same principals when it comes to a breeding program. My basic strains are the result of linebreeding for many years. Remember that accurate record keeping is a must in any breeding program. Let us assume you have just received your first breeding trio or pair of show guppies. The best size tank will be one that is small like a two and a half or a five gallon. If all goes well within a few weeks your females should start to drop young. Try to raise each brood in a separate tank.. Proper feeding which should include baby brine shrimp, along with weekly water changes will help the young grow to their potential. When the young are about three to four weeks old you should remove several of the better females and keep them virgin for the next few months. From the remaining young you can cull out the unwanted males and some females. I usually leave a few females in with my males to keep them chasing.
Within a few months you should have several tanks of juveniles of various ages. As the young mature culling should be a daily practice.. Culling is a way to discard runts and other lesser fish. Now it is time to select new breeders. I suggest picking one or two males from the same brood. If you are fortunate to have males that are similiar, then use the two male method. Next we will be selecting females. I recommend picking similiar looking sisters from the same line , but not the same litter that the males came from. If you have at least three available tanks for your new breeders, try setting up two parallel breeding tanks. In the third tank you may set up a male and several females that are brother and sisters and inbreed them. Some knowledge is required to select the right fish for breeders. A good strong peduncle as well as tail and body shape is equally important as color or pattern. Remember that the amount of breeders you set up will force you to have available the necessary tanks to raise all the future offspring. A simple way to label your breeders is to assign a number to each breeding tank. All young born from setup #1 will carry that number as well as the date they were born. This helps retain the identity of every litter. Label every litter/drop with the day they are born with the associated this will help you trace back every future drop to the proper parents. If you are not prepared to keep all litters separate, you will not be able to follow this method. Once your breeders are selected deciding what to do with the remaining fish can become a trying decision. . Perhaps you will be able to sell them to a local pet shop. This helps to free up tank space. If you intend to show some fish, then you will need a few tanks just to raise them to show size.
Inbreed brothers to their sisters from group A and group B separately. By doing this you will create two related parallel lines. When the next crop from your new breeders comes of age repeat the same procedure again. Hopefully a good percentage of your offspring are as good if not better than what you started with. After breeding for three generations of this type you will make a change. In addition to setting up your new group from A and B, you will now breed group A to group B. Select a male from group A and several females from group B and put hem together. You may also put group B males with group A females. We will call this a back cross. From the resulting offspring you will repeat the original breeding setup you began with group A and B. Remember the sibling breeders you set up when we first started, well we can now introduce them back into our line bred groups. Make one cross into the group from the inbred line, and call all resulting fry by a new group number.
Hopefully you will be seeing an improvement in your strain by this time. All this can be accomplish without seeking or introducing new stock into your strain. Many variations can be added to this type of line breeding. I have maintained most of my lines with this method. Once you have acquired an understanding of what it takes to maintain a pure strain, you can rise from the ranks of the novice and become an experienced guppy breeder.