Parental Care In Bettas: Abnormalities And Ways Of Dealing With Them

By Gene A. Lucas g.a.lucas@worldnet.att.com

Originally Published:

FAMA Magazine

February 2002

Vol. 25 - No. 2 - Pg. 94

I think probably the most frequently asked questions about Bettas, at least from people who try to spawn them, are those dealing with how the 'parent' Bettas behave. This covers getting them to spawn and, if they do, what happens before, during, and after the spawning. I'd reckon that these were also the most frequently answered questions too, but I don't recall having devoted an entire article to the subject myself. Since I have dealt with over eleven hundred spawns over the past forty years I have probably 'seen it all' and therefore thought I might be able to provide some possible useful information.

Since the subject is going to be abnormalities in the processes it seems appropriate to start by reviewing briefly what is normal; that is, what happens, or should happen, when things go right. I contend that Bettas must be one of the easiest of aquarium fishes to breed and I hope my descriptions will be convincing. I'll first describe the physical set-up, then the typical behavior of the fish.

The Spawning Tank

Most experienced breeders use at least a ten gallon aquarium, although they will readily spawn in much smaller or larger containers. Water depth is generally set at about six inches, though this also tends to suit the breeder, not the fish. Again, they will spawn in water of almost any depth starting at around an inch. They do not seem to require a limited range of water quality factors such as pH or hardness, but fresh, clean water seems to have a stimulating effect. The temperature selected is usually 80 degrees F, assumed to be optimum based on an experiment reported years ago which found that bubblenest building in jars was most active at that temperature, and tapered off rapidly within three or four degrees above or below. Once again the Bettas seem unaware of this importance and, given reasonable opportunities to adjust, they will spawn over a somewhat greater range.

Tanks may be planted or plain, contain gravel or have bare bottoms, and be well or poorly lighted. Usually a plant with a few floating leaves or an artificial substitute such as half of a Styrofoam cup may be introduced since these seem to stimulate nest building. Male Bettas will build bubblenests without either, as amply evidenced by the constant building of them even while they are isolated in jars. The male is typically introduced to the tank first although some breeders introduce both adults at the same time. The time lag, if employed, can range from an hour or two to several days.

Normal Parental Behavior

The male selects a site, usually under or near the floating materials, next to a filter or heater tube, in a corner, or, least likely, just along a side. Assuming both parents are sexually mature and in decent breeding condition, the male will commence adding to the nest and swimming back and forth between the nest and the female, spreading his fins and gill membrane to show her how grand and desirable he is. She will finally approach and join him under the nest where they will soon sidle up to each other and he will wrap around her. She is usually turned over and his head and tail draped over her. The position probably places their ventral openings near each other so that their eggs and sperm, which are emitted into the water, are close together which presumably increases chances for fertilization.

At first no eggs may be released, then a few and, during the main stages of spawning, there may be thirty or more released at each mating act. After each, the male busily picks up the eggs, which sink toward the bottom, in his mouth and places them in the nest along with more bubbles while the female hangs in a kind of trance of inactivity. These spawning 'embraces' are repeated every few minutes for a period of as much as several hours. As the spawning slows, fewer eggs will be released and finally they stop.

The male then begins to very actively tend the nest, adding bubbles and replacing any eggs that get dislodged. The female retires to a distant corner. The male becomes very protective and will range out to drive away any intruder, including the female. She should then be removed from the tank lest he may attack and injure or even kill her. The eggs develop rapidly, hatching within a couple of days. The fry are not completely developed and if they wriggle free from the nest may not be able to return to it. The male continually collects and returns them, adding new bubbles all the while. After another couple of days his job is finished as the fry become free-swimming. Some males become quite debilitated and others may eat the free-swimming fry, so it is best that they be removed and allowed to recuperate.

Abnormal Parental Behavior

A list of things that parent Bettas do that is not normal can commence from the beginning act and follow through the sequence. I will go through these variant behaviors, then in a following section comment on possible ways to get around them:

1. The male does not build a bubblenest or if he does he doesn't put it under the cup.
2. The male seems to pay no attention to the female.
3. The male savagely attacks the female and seriously injures or kills her.
4. The two fight like two males and either or both may be seriously injured or killed.
5. The pair do not seem to know how to make proper spawning embraces.
6. During spawning the female eats eggs almost as fast as they are released.
7. The male doesn't maintain a proper bubblenest or care for eggs or fry.
8. The male may eat the fry, either during their larval stage or after they are free-swimming.
9. The female, the male, or both, may come out of spawning in poor condition. They then sometimes will not feed and may deteriorate or even die.

I believe this pretty well covers the things that 'go wrong' when someone tries to spawn a pair of Bettas. Obviously, these fish are not behaving as expected and should be regarded as behaving abnormally. Although in some of these cases a few offspring might be recovered, the outcome is usually a completely unsuccessful spawning effort. So what can be done to overcome these faults? Are there things that could be done to prevent or get around them? The answer is, yes, there are some things that can be done and once in a while they work. I'll present and comment on each in the same order I presented them above.

1. Building bubblenests seems to be one of a series of responses to certain physical or physiological cues. Some are similar in other species and a few very much like these. Some may be mimicking things that happen in the wild. Freshwater changes and sometimes temperature shifts (within limitations) often trigger spawning activity. Since building nests presages breeding, duplicating this physical shift may help. Most breeders set up tanks with new (but aged) water. Male Bettas will routinely build nests in their jars after water changes which may have suggested doing that to early breeders. It often works.
   
   Bettas seem to prefer building nests under leaves or other floating materials, so placing plants or other floating things in the tank will often stimulate this activity. Studies have indicated that they prefer light green, yellowish, or white over other colors and objects that present an area of six or eight square inches. The size seems to be selected over smaller or large objects. Modern breeders almost universally use small Styrofoam cups which have been split longitudinally. The cup is floated on its side, open side down and males build their nests under them probably 95% of the time. A flat piece of plastic also can be used and one person reported using a bit of whipped egg white. Bits of bubblenests made by other males (from jars, for example) may also work. The main point here is that having plants or these artificial materials in the tank may help induce the male to make a nest.
   
   Presenting a female where he can see her, even if she is kept separated in a jar or by a partition, will also often stimulate the male to build a nest. Another ploy that occasionally works is to float a jar containing another male in the tank or set the jar where it can be easily seen outside the tank. Nest building also seems to occur as a kind of displacement behavior representing either defense of a territory or competition for a mate. The frequency of nest building in jars might also be attributed to this in addition to water changes.
   
2. Males which ignore females are frustrating. Some are possibly not in good condition. If they have been spawned recently, or a number of times they may just be worn out or tired of the notion. Others may be getting too old (I don't think being too young is a factor ... I have had them spawn at seven weeks of age!). Some males, especially in some genetic lines, seem to have a lower sex drive than others. This has been experimentally related to attempts to breed for less aggression. Finally, some males just seem to prefer some females over others.
   
   The first thing I would be sure of was that they were healthy and in good condition. If they are normal sized, active, and responding to their neighbors, in good color and do not have clamped fins, they are probably in good enough condition. Bettas have a relatively short life span and are probably in good spawning shape from about two or three months to less than a year. Most lose interest at about that age and there isn't a cure for getting old.
   
   Fish with low response levels may be 'cranked up' by a little training. Placing a male next to several others, either in sequence or in a cluster, might provide one which raises his ire. Exposing him to one that is especially aggressive and displays continually may get him charged up. Showing him to several females might also work. Doing this daily for several days might end up putting him in the mood.
   
   Showing preference for one female over another is probably just 'human nature,' so to speak. Betta breeders who have plenty of fish around can just substitute. Use another female ... or even another male with the first female. I always keep a few males and females of each type around for such eventualities. For the casual breeder who doesn't have extra fish, this is obviously not a solution but even the best breeders at times cannot get spawns from the fish they want. If you just want to get a spawn and all else fails, go get another female.
   
3. Ordinarily, a male Betta will savagely attack a female for one of two reasons. She may not be responding to his amorous advances and he is increasing his level of attempts to drive (rather than entice) her to his nest. The more severe the attacks the more frightened she might become and the less likely that they will spawn. Sometimes, in the end, she will finally relent and the spawn goes on, though she may be somewhat beat up after the fact (the classical battered mate?). If she is an important or valuable female, I would remove her rather than wait to see if that happens. Then I would substitute one or both parents or wait and try the spawn again later.
   
   The other possibility is that they have spawned already and no one happened to see them doing it. They sometimes spawn within a couple hours after they have access to each other. After spawning, most males quickly shift from being lovers to being protectors and most are very good protectors indeed. The female unwittingly is transformed from partner to intruder and she will be emphatically treated as such. The female may flip up and stick on the side glass or lay on top of things like the Styrofoam cup. These are sure signs she is trying to escape and he doesn't want her around anymore. He will also stay tight with the nest and working on it. The eggs may get worked up in the bubbles so they can't be seen, so the fact that you can't see them shouldn't be taken as proof they aren't there. He will take an occasional pass around the tank and will attack anything he doesn't like.
   
   Females which have been under attack are easy to identify. They will have torn and battered fins and may be missing patches of scales. They will usually be very pale in color and, if of the right color, will be showing their fright banding. They will dart fearfully about the tank if they see the male approaching. Needless to say they should be removed immediately lest they be killed.
   
4. If a female fights with the male, the mating attempt should be terminated immediately. It is not normal for any ordinary female to fight with a male and it is safe to say the outcome will not be what the breeder had in mind. There are several possible explanations for why this might happen, the most likely being that they are not a normal male-female pair. Some females have longer fins and appear to be males and short-finned males are often mistaken for females. Whenever two of the same sex are placed together they will most likely fight, even two females. At the very least one can assume that matings involving same sexes cannot be successful. I suspect if a small male is paired with a large female they might be able to carry on a fight but most breeders would not set up pairings unbalanced enough for that to occur.
   
   Usually when these things happen it is the result of mistaken identity. Closer examination might have revealed the correct sexes. Quite often older female Bettas turn up that have gone through sex reversal. When that happens some of them can actually produce sperm cells and thus become the father of broods. I'll not attempt to give the details of how this can happen here but it can, does, and has even been experimentally induced through surgery. Female to male sex reversal leads to longer fin growth (in long-finned types at least) and alterations in behaviors including increased aggression. The solution here is to break up any fight going on and be sure you have correct sexes next time you set up a mating.
   
5. Although it may seem that the pair are not completing the spawning embraces properly, it may not really matter. I never believed male Bettas actually squeeze eggs from the females while wrapped around them but rather merely got their ventral openings positioned near each other so that eggs and sperm were close together upon release. I doubt if the anatomy of the fish would allow for much pressure anyhow. The ventral proximity might help increase the percentage of eggs that get fertilized but I doubt that it is necessary.
   
   My guess is that at least some inexperienced males may not know how to spawn in the recognized manner but that they will probably get it right after some practice. I believe there are enough sperm around alive in the water during spawning to take care of all the eggs so long as they get placed in the bubblenest. Eggs that remain on the bottom probably will not hatch, either because they don't get fertilized or for other reasons. At any rate, I think this is something that really isn't a problem.
   
6. I don't know why females eat their own eggs but some do and you would think they were a real delicacy. Those that do seem bent on doing it even if they are well fed and fed during spawning, which ordinarily we would not do. It may be that really well fed females have learned to be gluttons and will go after anything that looks good! I am more inclined to think the problem starts with a sluggish male. Normally the female remains briefly in an inactive 'trance' after a spawning embrace while the male busily goes about collecting the eggs and putting them in the nest. If he is slow to do this and she gets reactivated while all those eggs are still there to be had, she may start feeding on them.
   
   Slow acting males and egg eating females may just turn out to be useless as breeders. My reaction is to try them at another time or set up a different pair. It is frequently possible to dip out eggs from such a spawning pair and hatch them 'artificially,' meaning away from the spawning tank and parental care. I have found it almost always successful. I place the eggs in water about a half inch to an inch deep and put a sprig of plant in with them along with a spoonful of the bubblenest. These are to provide (presumably) sperm to fertilize any eggs that haven't been and resting places for new hatched fry until they are free-swimming. They also harbor infusoria which can provide food for the new baby Bettas.
   
7. The failure of some males to maintain their bubblenests or care for their young seems a bit odd because in most cases they have spawned as expected and probably tended the eggs normally for a couple of days. I am only speculating but I'll offer some commentary for whatever it might be worth. I'd guess that this mainly happens when the spawns are large, that is when there are large numbers of fry to tend. I once reared to maturity 577 fish from a single spawn and we know a medium-sized female can put out over a thousand eggs so there is at least the potential.
   
   Once the fry hatch and start wiggling themselves out of the bubbles, they can be observed almost 'raining' down beneath it while the male almost frantically tries to collect and return them to the nest. This is a job with no relief and it lasts for around forty-eight non-stop hours. During this time the nest may expand to cover half (or more) of the water surface in a ten gallon tank. This effort might be compared to a human with a lawn of an acre or so mowing or raking it continually for the same amount of time. It would come as no surprise if this effort became at least boring.
   
   More likely, however, the fish may merely be wearing out. Imagine the energy it must be using up, especially since it is not feeding during this time. To put some quantitative meaning to this, I calculated how many times a male would need to pick up and replace Betta fry into the nest during the two-day larval, pre-free-swimming stage of a spawn. If there were 300 fry and each shook loose about once every half hour, that would be 300 times 2 times 48 hours or 28,800 times! Of course this required assumptions which may be way off but seem reasonable. There may be some respite during hours of darkness. The male may gather several at a time. Possibly they don't fall that frequently. But no matter how it shifts, this is clearly a major effort for the father. No wonder some of them give up.
   
8. It isn't often that males eat their young. Many reports have been made of spawns where young have grown up in the tank with one or even both parents. Obviously they are not isolated in the wild. Nevertheless, sometimes it happens in aquarium bred fish. In cases like I wrote of in the previous section, one might figure they do it because they get frustrated. Maybe they also finally get hungry. Probably it is some combination of these and possibly other factors. Whatever the reason it is probably nothing that can be predicted, so the only advice I can give is to try to watch males, especially those caring for big spawns, and remove them if they start eating the fry.
   
9. I imagine it is inevitable that the parents will be run down after spawning, no matter how good their condition was beforehand. Remember, the female has ejected a mass of eggs and the male has also spent considerable substance in the form of milt (containing sperm) and the mucous presumed necessary for helping form the bubbles that make up the nest. They have both been physically active for several hours during the spawning process. Little wonder they should be run down. It's probably more amazing that they come out of it as well as they do. Many can be spawned again within a couple weeks. I think females can probably be re-spawned more often than males, possibly because they may have eggs that weren't released during the prior spawning and they haven't had the male's additional stress of rearing the fry. My recommendation is to always give both males and females plenty of time to recuperate ... several weeks if possible. Always be sure they are in good condition for new trials although the fish will probably reveal their readiness by how they act.

Discussion

The sad reality of these failed spawns is that they for some perverse reason frequently involve the matings (and resultant progeny) one most desperately wishes to obtain. They involve some specific outstanding individual or one which is involved in a line of research or the development of a strain. For the newcomer who is trying spawns for the first time, I would add that almost everyone seems to have difficulties at first. Bettas have to be among the easiest of egg layers to breed and suddenly you will have success which, if you continue to follow up, you will find almost becomes routine.

Be patient. After a few tries you will succeed. Most spawns do not involve any of the problems I have reviewed in this article. I am confident that after a few tries you will discover that you can breed Bettas just like 'the experts' and you won't often have to deal with abnormal behaviors. Good luck!