Do microworms cause of lack of ventral fins in betta fry?

[Aniket]

I have heard if we feed microworms to betta fry they will loose their ventral fins
Is that true?

 

[Colin_T]

no.

if fish fry do not develop fins it is because there is a genetic fault with them.

 

[Aniket]

no.

if fish fry do not develop fins it is because there is a genetic fault with them.

Oh then i can use them for feeding

 

[Colin_T]

Assuming the fry are big enough to eat them, yes it's fine to feed them to fish.

 

[Demeter32]

Sorry but I must disagree with you Colin. I have first hand experience with micro worms causing missing pelvic fins. It was my fault really, I wasn't cleaning up after each feeding so the left over micro worms rotting at the bottom caused their pelvic fin buds to "burn" off. Not all the fry were effected but most of them were. Some have only one pelvic fin, some have none, and a few have stubby little fins. It is not genetic, both parents have perfectly functional pelvic fins and another batch from the same father but different mother have perfect fins.


I've heard it happening before and will link something here:
https://bettaboy.wordpress.com/2017/08/01/why-my-betta-fries-got-no-ventral-fin/

This male had 2 stunted pelvic fins

These boys have none

This female has one perfectly normal fin

Brother from another mother has 2 perfect fins

 

[NickAu]

Demeter is right its not genetic, its down to water quality

 

[Aniket]

Sorry but I must disagree with you Colin. I have first hand experience with micro worms causing missing pelvic fins. It was my fault really, I wasn't cleaning up after each feeding so the left over micro worms rotting at the bottom caused their pelvic fin buds to "burn" off. Not all the fry were effected but most of them were. Some have only one pelvic fin, some have none, and a few have stubby little fins. It is not genetic, both parents have perfectly functional pelvic fins and another batch from the same father but different mother have perfect fins.


I've heard it happening before and will link something here:
https://bettaboy.wordpress.com/2017/08/01/why-my-betta-fries-got-no-ventral-fin/

This male had 2 stunted pelvic fins
View attachment 89683

These boys have none

This female has one perfectly normal fin

Brother from another mother has 2 perfect fins

At what age you were feeding them microworms?
My fry are 1 month old.
Is it ok to feed them microworms?

 

[Demeter32]

I was feeding them micro worms starting a few days after they were free swimming. At one month old they should be eating larger food items like baby brine shrimp, but micro worms will be accepted as well. Keep in mind that micro worms do not have a lot of nutrition so the sooner you get them on larger foods (brine shrimp, daphnia, chopped blood worms etc) the better.

 

[Colin_T]

... It was my fault really, I wasn't cleaning up after each feeding so the left over micro worms rotting at the bottom caused their pelvic fin buds to "burn" off...

It wasn't the microworms that caused the fins to get damaged. It was poor water quality (probably ammonia) that harmed the fry. And any uneaten food that rots on the bottom will also harm the fry, be it newly hatched brineshrimp, powdered fry food, bloodworms or anything.

Microworms are a safe food to feed baby fish and do not cause missing or damaged fins.

Poor water quality caused by lack of water changes or lack of or no filtration will cause deformities and even kill fry.

Too much carbon dioxide and any carbon monoxide will also cause deformities in fish fry.

 

[Demeter32]

It is more often caused by feeding micro worms though, because they sink faster than foods like baby brine shrimp and the betta fry will be near the bottom looking for fallen worms. In theory the bottom of the tank will have a higher concentration of ammonia and whatnot that is being produced by the rotten food, which in turn seems to burn off their forming pelvic fins. Seems plenty logical to me, otherwise their other fins would also be effected to some extent, which mine do not seem to have.

You will rarely see the same issue when feeding strictly live BBS. I know the micro worms themselves do not cause the problem, it is when they rot as I stated before. Of course micro worms are safe for fry to eat, I've been using them for a long time with no ill effects on passed betta, cichlid, danio and live bearer spawns.