Selective breeding - How to create your own line?  
    By Joep H. M. van Esch    

This article was published in Flare (Journal of the IBC) - March/April 2009, Volume 42, No. 5.

With selective breeding, hobbyists try to fix certain traits in their lines. But how do you start to create your own line? With this article I tried to answer this question based on my personal thoughts and experiences.

Additional note: In example 1, 2 and 3 you will find several codes which I use to log my spawns, this to make it easier to check the background of the fish bred in my fish room. The spawning code is composed out of: (I) BT (Betta Territory) and (II) The spawning-date (day/month/year). A more detailed log of these spawns can be viewed at my personal website by selecting “Spawn-log” in the menu.

Everybody can buy quality fish, but not everybody can breed quality fish! The spawning process and raising the first generation out of a purchased pair is often fairly easy but then the hobbyist will stand for the difficult task to choose his/her own future breeders. But where do you start from grow-out tank full with fry? Usually the real breeders will stand up from the crowd as they are able to at least maintain or improve the quality of the line they initially acquired. Improving a line usually also means outcrossing to fish from another line in order to bring in the new desired traits you want to fix in the generations to come. At this moment people actually are creating their own unique line. But how do you successfully create your own line? The answer to this question is not easy as there are multiple ways to achieve this goal. Each breeder has to find THE method(s) which suits him/her best. Creating your own line is actually nothing more than a puzzle in which we try to combine the right pieces in order to come closer to our goal(s).

Based on my own experiences, I summarized a few important points which may help you in the process of developing your own line of bettas:


·    Focus: When you start working on your own line it is important to keep in mind that the term “line” is not the equivalent of just performing one spawn but of a complex breeding program in which closely related animals are interbred in order to fix certain desired characteristics. This implies that you will need several tanks and multiple jars in order to maintain a healthy line. With the broad choice of color and finnage varieties we have within the betta-scene, keeping focused is not always an easy thing to do. New hobbyists often underestimate the time it takes to breed and maintain a quality line of bettas. In their enthusiasm, they are easily tempted to purchase several color and finnage varieties to start with. By the time that they realize that they do not have the space and lack the time to raise all these youngsters it is often too late. Because the new hobbyist is overwhelmed by the amount of work, he/she is not able to give the fish the necessary care. This will negatively influence the outgrowth and the health of the fish. Sick fish and disappointing results are often the cause of the fact that many promising new hobbyists quit our hobby. In the long run it therefore might be better to keep your focus. With respect to color, a good solution to keep diversity in your fish room with only a limited amount of fish, is to work on color varieties which can be easily combined. Some examples are for instance red, orange and yellows or the iridescent colors (turquoise, steel blue and royal blue) in combination with melano black, black lace and/or the metallic trait. With respect to finnage also several varieties can be combined. Some examples are for instance the halfmoon, doubletail and crowntail traits which can be combined with both long- and shortfinned bettas.


·    Strict selection: The size of a single spawn can range from a few fry up to several hundreds of youngsters. Among these youngsters you usually will only find a few fish showing (some of) the desired characteristics you are looking for. Selection definitely is not easy. Some lines will show their quality already at a young age whereas other lines need more time to develop this. Keep in mind that outcrossing also can influence the way a certain line develops. By working with your lines you will also train the eye to spot certain positive but also negative characteristics. An example of a desirable trait which is easy to spot at a young age is a broad-based dorsal (Figure 1), whereas less desirable traits are for instance extreme rosetail features (Figure 2) or a crooked spine. By selecting maximally 4-8 fish per spawn showing (some of) these desired characteristics you will force yourself to only keep the (top) fish to work further with. In the more inbred lines, where the desired traits have been more fixed, the selection will get more and more difficult. In time, you will notice that as your line improves, your goals also will be adjusted again to an even higher standard. Strict selection not only increases the probability that certain desired characteristics will be fixed in your line, but also mean less work in maintaining all those jars with fish you will not use for your future breeding program.

Figure 1: Broad dorsaled young male (7 weeks old)
Figure 2: Young copper/gold rosetail (6 weeks old)

·    Work with your fish: As mentioned before, it is very easy to purchase new fish but usually a breeder gets more satisfaction from working with the fish that he/she has bred him/herself. Working with your own fish also has a big advantage as you will get to know the genetic potential of your line. The genetic background of newly purchased fish often is a mystery. It can be very difficult to retrieve information about the background of a certain fish or line due to the fact that often the breeder is unknown, the communication with the breeder/seller is difficult or that the breeder does not keep a detailed record of his/her lines. Some characteristics are easily spotted in the phenotype of your fish but your fish also might be a carrier of several other traits which are not visible in the phenotype. It sometimes can take multiple generations in order to find out what traits are hidden within a certain line.


Example 1: This example shows how I personally started my metallic HM PK line. In 2004 I purchased a longfinned copper HM pair (Siamimbellis, Thailand) which gave me a nice longfinned copper HM male in the F1 generation (BT240404). The copper HM male was also crossed to a longfinned metallic blue female (Magicbetta, Belgium) which was a F1 offspring of a green HM pair (Bluebetta, Thailand). First, a blue metallic female of this spawn (BT040904) was crossed to the copper HM male (BT240404) which gave me a platinum/pastel transitional PK (BT220105A). Secondly a platinum white sister (BT040904) was crossed to a blue marble HM PK male (Ploybettas, Thailand) which gave me a broad dorsaled blue female (BT200205). In may 2005 I then crossed the platinum pastel transitional PK (BT220105A) and metallic blue female (BT210505), and my first quality HM PKs were born (BT210505)!


·    Create multiple options: In order to achieve a certain goal, either finnage or color wise, you often need a few years of work. You will notice that not all spawns will bring you the results you where hoping for. Off course the easiest way to improve your line is to purchase new fish but you will see that this is not always necessary. With only a few fish it is possible to create multiple options which enable you to improve your lines for at least a year without the need to buy new stock. Example 1 and 2 below, but also example 3 later in this article, show fish which where bred in my own fishroom by using the stock available and creating multiple options in a time-span of about one year.


Example 2: This example shows how I personally started my red HM PK line. In 2007 I got a red HM male (Siamimbellis, Thailand) which I crossed to a red traditional PK female (bred by Daniella Vereeken, Belgium) The F1 offspring (BT060507) showed a very good red color with finnage between that of a veiltail and delta. Before I could select my future breeders the offspring spawned several times at an age of 2.5 months in the grow-out. This F2 generation (BTXX0707) brought a few PK males with extremely long anal finnage but good shaped dorsal and caudal finnage. One of these F2 males was crossed to a sibling sister to obtain the F3 generation (BT030408). The same F2 male was also crossed to a PK female which was the result of a red HM PK pair (Satornbetta, Thailand) to create a related line (BT100208).


·    Use the building-blocks which are available: It is not always possible to purchase the fish you would like to reach your goals with. Keep in mind that there are more ways to reach your goal. It is perfectly possible to reach your goal by working with fish showing only a few of the desired characteristics. Sometimes we have to compromise by going one step back in order to go a few forward in the long run. This often might take a bit longer but the satisfaction will be much greater when you finally succeed to reach your goal.


Example 3: Example 1 nicely showed how I started to work on my darkbodied metallic HMPK line. In 2007 I wanted to experiment a bit with “dragons” in order to improve the metallic iridescence of my own line. Off course I would have preferred to experiment with a dark bodied HM PK dragon but as I was not able to purchase such fish I had to look for other options. At a show in Hannover, Germany I managed to purchase a yellow dragon traditional PK female (Dong, Thailand) which was crossed to a silver copper HM PK (Banleangbettas, Thailand). The silver copper HM PK male (Banleangbettas, Thailand) was also crossed to a royal blue HM PK female (BT290906B) from my own line. The offspring of BT170307 was homogeneously copper/red bicolor with a very thick iridescent layer. Their finnage was ranging from transitional PK towards a more symmetrical HM PK type. I decided to cross young female from this spawn to two brothers, one a more transitional PK (F2, BT050807) and a more symmetrical one (F2, BT171007A). Although I expected more from BT171007A, I was surprised to see that BT050807 gave me much better balanced fish with promising finnage. BT171007A was nice, but nothing special and unfortunately several extreme rosetails popped up which were culled (indicated with the red cross). The more symmetrical brother was also crossed to a metallic blue half sister from BT010407 which resulted in (BT271107) offspring with an impressive thick iridescent color and promising finnage. With this example I wanted to illustrate that it is still possible to achieve your goals by working with the building blocks that are available and by creating multiple options.


·    Do not breed your fish too young: The first bettas being able to reach a 180 degree spread were bred by Guy Delaval. The CHENMASWIL team (Laurent Chenot, Rajiv Massilamoni and Jeff Wilson) then further perfected these fish to what we nowadays call the halfmoon. In their breeding program they were aiming for vital fish which where able to hold their finnage and balance throughout their lives. These selection procedures became less strict as the halfmoon trait became more and more spread around the world. Many breeders wanted to get quick results and started breeding their fish at younger ages paying less attention to these selection procedures. This resulted in the fact that we nowadays often see fish reach their peak at 3-4 months of age, whereas they are not able to hold their finnage anymore and often loose vitality at an age of >6 months. At this stage it is often nearly impossible to breed these fish anymore. Bettas already can be sexually active at a young age. Several breeders have encountered youngsters spawning in the grow-out tank at an age of 2-3 months of age, but does this mean we should breed our fish at a young age? Although our fish are growing throughout their whole life most of them usually are reasonably developed around at 5-6 months of age. Certain important characteristics, both positive and negative, are not visible in young fish but only appear when a fish reaches maturity. Some examples are for instance vitality, overall balance, fin curling, ability to hold their finnage, susceptibility and resistance for disease, rosetail influence, fin curling, etc. So it is important to keep in mind that when breeding fish at a young stage,there is a risk to overlook certain important characteristics you might not want to fix in your line. Another important issue which comes up with breeding fish at a younger age is the fact that the peak of these fish will also be at a younger age. The key to change this lies with the hobbyists themselves but keep in mind that this probably will need a few generations.


·    Do not plan ahead too far, observe: Breeding closely related fish is often used to fix certain traits in a line. A few examples of such crosses are for instance brother x sister, father x daughter, mother x son, nephew x niece, etc. Here it is important to realize that there is no fixed program which will always ensure a successful outcome. Most hobbyists will have a certain approach in mind when they are starting to develop their own line. During the process most breeders will experience that certain things will not always go the way they have planned and that they might have to take another route to reach their goal. Observation here plays an important role, as in each generation you will have to select those fish showing the traits you would like to work further with.


·    Trust the genetic background: Keep in mind that a show fish is not always a good breeder, and a breeder does not always have to be a good show fish. The phenotype does not always say something about the genotype. A good looking fish can also be that one top fish from a big spawn whereas better results are to be expected from a phenotypically less beautiful fish from a quality line where some important characteristics have been fixed through several generations. We have to keep in mind here that the phenotype is not determined by genetics only but also by environmental factors such as water quality, temperature, food, and more. Off course it is always smart to ask the breeder for some more information about the background of the fish you purchased but unfortunately this is not always possible. In such case the only way to find out is to work with the fish.

Figure 3a: Royal blue mask HM PK male (Dennis Tan, Singapore)
Figure 3b: Royal blue mask HM PK female (BT290906B)

Based on his unbalanced overall appearance and bumpy topline, the royal blue mask HM PK male (figure 3a) would not be the first choice to work with for many hobbyists. I purchased this male at the first Bettas4all Show in 2006 in Amsterdam, the Netherlands. Although on the other side of the world, I had been following the development of this line by Dennis Tan with great interest on the forums. I was very happy to hear that he also wanted to enter some fish to our show. Unfortunately, most fish did not make it due to problems with the shipment and this was the only male left of the line I so badly wanted to cross into my own line. I decided to trust the genetic background of this guy and crossed him with a royal blue HM PK female of my own line. The result was one of the best females I had bred so far (figure 3b). This royal blue HM PK female is also depicted in example 3.


We all want to reach our goals as quick as possible but usually this will need several generations. Several generations, means several years of work and this will require a lot of patience which is not always easy, but it is definitely worthwhile. I hope this article will encourage hobbyists to work with their fish in order to find out what is hidden in their genetics. While doing this, do not be afraid to cross different colors and finnage types. Finally, I will end with one of the most important points when breeding bettas:

Enjoy your hobby!



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