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Marianne - All my fish are kept in one system the water flows from a central filter into all the tanks, so fish are all getting the same water same water changes at the same time. 4 spawns spawned with in hours of each other, 2 spawn ventrals intact 2 without ventrals. I think I have proved pretty much water changes and water chemistry have nothing to do with it. Same as pH and water chemistry to sex of fry. Those same 4 spawns 3 50 50 males female 1 spawn 95% female. 2 spawns had 150+ fry 2 50+.
- Jan 27, 2001
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Hal - It is my guess that this is a bacterial infection rather than a congenital condition. My reasoning being that this type of mutation would select out of the gene pool so quickly that we would not see the frequency which seems to be happening here. A fish with no ventral is a dead fish swimming, and the mutation can not move into the population as other than a recessive trait. Yet we see whole spawns of these fish.
- Jan 26, 2001
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xeries - I said water CHEMISTRY not water changes. I believe someone else was putting forth that hypothesis.
I made several observations concerning the SUCCESSFUL living members of several different spawns. The big source of uncertainty here is all the fry that may have died, been eaten by mother or father, or eggs that didn't hatch that we don't know anything about... and may or may not have had missing ventrals.
In this series of observations, fry from different spawns from the same parents were observed. The first set of spawns took place using a water source in Florida and there were no SUCCESSFUL fry (those living to observable size) with missing ventrals. One of these spawns was transported from FL to VA. This transitory spawn later had successful fry with missing ventrals. The second set of spawns took place using a water source in VA. All spawns to date have shown one or more successful fry with missing ventrals.
In this case we have TRIED to eliminate variables concerning the genetic source (we used the same parents). Mr. Ahmer and others who understand genetics will pipe in and say that the nature of inheritance will not allow you to eliminate that source of variability and be entirely correct.
I'm not sure if gender ratios pertain to this discussion, but are of interest as well on a different topic. I hope you will continue to explore that topic in the future as you have done recently on the IBC list.
Your observations have kept the water source constant which is very good. However, unless the flow in your system is 100%, there are different amounts of accumulated matter in the tanks which will alter chemistry (as well as the binding rate of deleterious chemicals-consider also the susceptibility of different lineages to those chemicals as well as some may be more resistant than others). Also, you have not discussed the lineage of the parents of the different spawns and whether or not their ancestors have produced fry with missing ventrals using a different water source other than your own. These are avenues for you to discuss if you have explored them already or for future observation if not.
Swinging back to the observations I have made previously. Sorry, I swing the conversation here and there sometimes:
I have not had the opportunity to spawn another lineage of fish and repeat the previous set of observations. I have, however, spawned a different lineage of fish in VA and found missing ventrals. I have started a plakat lineage just recently and results are still pending. A spawn of both lineages that have produced missing ventrals in VA however have been spawned in FL and there have not been any successful fry of that spawn with missing ventrals. Other spawns of these lineages are planned in FL in the very near future and will perhaps further indicate similar results.
So for now, further observations are needed, but remember sets of observations (in the case that the observations are discussing a different set of variables) can't be compared like apples and oranges don't create an apple pie but rather apple/orange pie. :)
Separate sets of observations need to be recorded in enough number that at some future date they may be compared when the number of observation sets multiplies to the point one can create a theory.
So what's the point? Well, first of all our discussions on this board alone have indicated at least four possible sources of missing ventrals! We are all considering the possibilities. Once we've figured out enough of the possible causes and have tested for them, we can start on a theory.
- Jan 27, 2001
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zlher - I believe that individual's skills with breeding and caring is more at fault that water changes! ...genetics also plays a big role in missing ventrals. Your fishes may have come from a line so inbreed who knows what it will produce. Most breeders DO NOT cross out when they have an established line and your fry with missing ventrals may be the end result of that work.
- Jan 26, 2001
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ahmerb - First, I won't argue that there's not a genetic component to missing ventrals. However, the statement that it is caused by too much inbreeding is just not logical. Let's name the gene for missing ventrals "V". Let's say that a broken copy of this gene causes no ventrals to be formed. We'll name the broken allele "v", making it lower case to show that it's recessive. I would assume recessive since a heterozygote, Vv, would still be able to make ventrals because it has one good copy. Now if you have two parents that are both heterozygotes and cross them, 25% will be vv and be missing ventrals. If they happen to be siblings you get the same result, so what. The point is that when people then choose two babies from this batch to inbreed, they only choose babies with ventrals (either VV or Vv, the owner can't tell). In some generations, just by chance, the owner will eventually grab two VV parents and the bad gene is actually eliminated from the line!! So selective inbreeding can actually remove ALL deleterious genes from a line. I just don't understand why people keep blaming things on inbreeding! Obviously if you take two creatures carrying lots of the exact same recessives, as with a sibling mating, and cross them lots of the babies will be screwed up. That one observation makes people think that inbreeding is a horrible thing. But these same people need to look at that batch of babies a little more carefully. While a lot of them are homozygous for a recessive problem, a percentage of them are homozygous for both good copies and no longer carry the bad gene!! There's GOLD in them 'dar hills!!
OK, second pet peeve. Salt isn't a cure for squat. Now I won't argue that certain fish prefer a certain amount of salt in their water. For instance, mollies like it and many a saltwater fish is known to like it! (little joke there). But bettas could give a crap. They do very well without it. Now many people say this one thing which is very incorrect, "Adding salt kills bacteria". I'm a microbiology professor who does genetics on pathogenic bacteria and I can tell you for a fact that you could dump kilogram quantities of salt into your aquarium and the bacteria will think you're throwing them a party. They love the stuff! In fact, one of the mechanisms they use for determining that they just infected an animal, is that the salt concentration is higher than back when they were in the pond. They see the increase in salt, assume they're in an animal (along with a bunch of other signals), and activate virulence genes (in other words, they get grumpy!).
- Jan 26, 2001
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zlher - Water quality is without doubt one factor, but without extensive research with control environments...no one would know for sure. I based my posts around the conditions I exposed my fishes too and have never run across a batch with missing ventrals.
For those of you who have had missing ventrals, you can try using a tad bit of salt, 24 drops of Aquarisol, pH of 7.0 and a temperature of 80 degrees in your replacement water with future batches (10 Gallon). Consistency is KEY and you have to be consistent or otherwise you will never really know what the cause is.
Perhaps the tapwater being used by some is too alkaline or too acidic for the proper growth of ventrals.
- Jan 26, 2001
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xeries - Friend of mine reported SEEING very small fry bite each others ventrals off when she was looking at them feed under magnification. Just another cause to consider. Have noticed something in support of the water quality issue as well.
I used to breed in Jupiter, FL. Never had a missing ventral EVER!
I moved to Arlington, VA. The batch of fry I spawned in FL and brought with me to Arlington came up with missing ventrals. They made it through the change in water fine but suddenly I've had a consistent problem with missing ventrals.
These are the same lines of fish - no outcrossing. Both lineages came up with missing ventrals.
Hence, this is a good case for missing ventrals and the water chemistry argument.
My mother is currently spawning a mix of these lineages still in Jupiter, FL and thus far has not reported any missing ventrals.
Mixed results, but barring the infrequent event of another fry biting another's fin off, I'd lean toward the water chemistry end.
Also of interest, another major betta breeder has reported watching the ventrals "melt" off his fry during a water change in Virginia.
- Jan 27, 2001
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Donna - I'm not blaming missing ventrals on microworms, either, and I do regular partial water changes in my fry tanks, too. I'm going by a suggestion (from a discussion on one of the IBC lists) that came from angelfish breeders saying missing ventrals on angels often is due to various "nasties" on the bottom of the tank that infect the growth points for the ventrals. This happens because of the time the baby angels spend on the bottom of the tank. Gunk tends to collect there, regardless of how clean we try to keep the tanks.
Anyway this sounded reasonable to me, and since I don't really know WHAT causes the missing ventrals on bettas, I figure, what can it hurt to use all the ammunition I can find?! I do know my fry spend a LOT more time on the bottom of the tank when they are fed microworms rather than vinegar eels, and I figure the early weeks are probably when they are the most vulnerable to infection, etc.
- Jan 26, 2001
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