The story behind breeding a show calibre fish

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There’s more to breeding a show calibre fish than putting two pretty specimens together and hoping for the best. Show judge and breeder Dr. Joep Van Esch explains.

When aquarium hobbyists picture a Siamese fighting fish, Betta splendens, the majority think of lush finnage, arresting colours, the legendary aggression between males, and unique spawning behaviour. It can be hard to imagine that such extravagances could descend from the wild fish of the Betta splendens complex, but that ’s exactly where they come from. 

Siamese fighting fish were originally bred in Asia with the main objective of refining and enhancing their combative nature, fighting style, hardiness, size and colour. Victorious fighters were, and still are, sources of prestige and income for owners who pit their fish in bouts against those of other breeders. To get the best fish, breeding stock was selected on the basis of sparring successes, where winners became the models for each new generation of fighters. 

This same practice of breeding for preferential traits stands at the base of the various colour and fin form varieties of the ornamental fighters we know today. 

Where it all begins — Betta fry in a nest. 

What is selective breeding? 

In a wild population of fish, the individuals that are best adapted to their habitats have the greatest chance to survive and reproduce, passing along their successful traits to their offspring. 

Where this selection process doesn’t occur in a natural way — instead becoming an artificial process where individuals are selected for certain traits by human interference — we speak of ‘artificial selection’ or ‘selective breeding’. Within the aquarium hobby, selective breeding is routinely used to fix certain behavioural traits (to wean fish onto prepared foods instead of live, or to reduce aggression), and to develop or fix particular colour and form variations. Few domestic fish may be as enhanced as Betta splendens.  

When the aim is to breed Betta splendens to a show quality standard, it can be fairly easy for a hobbyist to purchase show quality livestock to work with. Unfortunately, breeding show quality fish is not as simple as putting two top show fish together and hoping for the best. 

The quality of the offspring depends on multiple factors including genetics, environmental conditions (such as water quality, temperature, and availability and quality of food), selecting the right fish to work with, and no small degree of luck. 

The spawning process and raising the first generation of fry from purchased breeding stock is usually straightforward enough, but then the hobbyist faces the fresh challenge of selecting the right future breeders. 

In order to maintain or improve on livestock quality, you’ll need to learn the genetic potential of the fish you’re working with, and understand which traits to look for when selecting future breeders. 

Selective breeding starts with close observation, comparing your own stock with the exacting standards of other breeders’ fish. 

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. Here it is important to realise that even experienced hobbyists won’t always succeed in either maintaining or improving the quality of their lines by selective breeding. 

Defining your own line

How do you breed your own show quality fish? And when can you say you’ve created your own bloodline? That’s hard to answer. Unfortunately, no one universal method ensures a successful outcome, and each hobbyist will have to find their own. 

Creating your own line is essentially a puzzle in which you combine genetic building blocks. It’s important to realize that the selection of a breeding pair largely depends on personal taste, and therefore results in a unique combination. 

When working on your own bloodline, you should remember that creating a ‘line’ is not the equivalent of completing a single spawn, but is instead the result of a continuous breeding program. During this exercise, closely related animals are interbred in order to fix certain desired characteristics. 

In my opinion, we can really speak of a line when (partially) related fish within this breeding program have unique, specific traits resulting from the process of selective breeding. 

Some of Joep’s own fry at 16 weeks. 

Consideration points

Based on my own experiences, I’ve noted a few important considerations when working towards your own line of show-quality Betta splendens: Focus: With Fighting fish available in numerous colour and fin form varieties, you can become overwhelmed and want them all.
But with zeal comes impulsiveness, and aquarists often purchase several varieties at once, underestimating what it takes to breed, raise and maintain a quality bloodline. Overpowered by the amount of work, neglect may creep in, negatively affecting the development and health of their fish. Repeated disappointing results from spawns, or a preponderance of sick fish, often causes all too many promising breeders to quit the hobby.

Work within your means, and only carry a manageable selection of fish in order to keep focus. To retain some diversity in colour and fin shapes with a limited number of fish, you could choose to work only with varieties that can be easily combined. 

With respect to colour, working with multicoloured or marbled fish may seem an easy way to add diversity, but this can also be achieved by working with solid, single-coloured fish. Non-iridescent colours like red, orange or yellow can be easily combined, and this also accounts for the iridescent colours — turquoise, steel blue and royal blue in combination with melano black, black lace or the metallic traits. 

With respect to fin form, varieties as halfmoon (HM), doubletail (DT) and crowntail (CT) can exist in both long- and short-finned fish but also can be interbred.

Work with your own bred fish: While it’s easy to purchase fish to work with, a hobbyist will get considerably more satisfaction working with self-bred Betta. 

The genetic background of newly purchased fish often is a mystery, and it can be difficult to retrieve information about its background where the breeder is unknown, if communication with the breeder or seller is difficult, and especially if the breeder did not keep a detailed record of the line. 

Some characteristics are easily spotted in the phenotype of your fish, but it could also carry other (recessive) traits which are not immediately obvious. It sometimes can take several generations before finding out which traits are hidden within a certain line. Working with your own fish offers an advantage, as the genetic background and potential is known.

Use the building blocks available: Ideally, you should work with fish that show all the desired traits you’d like to see in your own line. In reality, you’ll likely have to work with whatever is available. 

As long as you’re able to recognize and select the right building blocks in your breeders, you can approach your goal a few generations down the line. By selecting breeder pairs that compensate for each other’s flaws, you may see a combination of desired traits emerge in future generations. 

Often, you’ll have to go one short step back in order to go a few longer steps forward. This requires dedication and patience.

Needing one tank each, male Betta can take up lots of space. 

Create multiple options

To create your own line, it’s worth incorporating some degree of inbreeding by crossing closely related fish (for example, brothers with sisters, fathers with daughters, mothers with sons, nephews with aunts), and regular outcrossing in an attempt to secure the desired traits. 

With only a few fish, which can be interbred in various combinations, it is possible to create multiple options to work with. Because the offspring of these combinations can be interbred in various ways, you will
be more flexible with your breeding program, without a continuous need to introduce new bloodlines. 

Mature fish are preferable breeders.

Strict selection

The amount of fry showing desired characteristics can vary from spawn to spawn. Selecting the right fish to work with is definitely not easy and detailed observation plays a key role here. Some lines will show their qualities already at a young age whereas other lines need more time to develop. 

Outcrossing will influence the way a certain line develops. By working with your lines, you will also learn to spot both desirable and undesirable characteristics along the way. 

By forcing yourself to only keep the best four to ten fish to continue working with, you can increase the probability that certain desired characteristics will pop up repeatedly in the offspring. This also means less work in maintaining all those jars and tanks with fish you won’t use in your future breeding program. 

As your program progresses, the selection process will become more difficult as a greater number of fish within a spawn will show desired traits. At this point, breeding goals should be adjusted to an even higher standard.

Don’t start them young

Betta splendens grow throughout their whole lives. Most are reasonably developed at six or seven months, and they can be sexually active from just three months. But should we spawn them at this age?

When selecting future breeders, it is important to realise that assessing for key characteristics — vitality, shape of body and finnage, overall balance, the ability to hold finnage, excessive branching, fin curling and the susceptibility for disease — require a fish to be fully matured. 

Breeding an underdeveloped fish before these characteristics can be assessed can result in undesired traits being fixed within your line. Hurrying your breeding program will often result in a line of fish that peaks at a young age, only to be over the top once fully matured. I prefer to breed my fish between six months to a year.

All hobbyists want to reach their goals quickly, but this usually will need several generations. That entails several years of work and requires considerable patience. You will encounter ups and downs along the way, but the end result is pride and satisfaction, plus a breathtaking line of your own fish.