When do fry start to grow ventral fins?

[alunjai]

My fry are 5 and a half weeks old and starting to colour but I can't see any ventral fins. At what age do they start growing?

[aemaki09]

Hmm, I started seeing ventrals at around 3.5-4 weeks...maybe a tiny bit sooner on the larger ones. They are tiny though so you have to look close

mine are 6 weeks now and I can see them well on everyone.

[alunjai]

I definitely can't see any ventrals. I heard they end up not growing ventrals if they feed off the bottom cos of the bacteria? My original container ended up being really dirty even after siphoning everyday.

Are yours swimming normally? Mine seem to be struggling to swim and lethargic. Not sure if its something to do with the water temp, water quality or lack in food nutrients? I only have 4 fry left from 50 :(

[LittleBettaFish]

It's believed that decaying microworms leads to bacteria being formed on the bottom of the tank that stops the growth of ventral fins in fry. If you have been feeding predominately microworms and then not siphoning the uneaten food and waste out on a regular basis this could lead to missing ventral fins.

I don't think anyone has really proven what causes it but the microworm/bacteria theory seems to be the most accepted.

What have your fry been getting fed and what are the details relating to your set-up such as size, temperature, amount and frequency of water changes?

Could help answer some of your questions.

Have you tested for ammonia? Fry are particularly sensitive to it and it can build-up fast in a grow-out tank.

[alunjai]

I only feed them live bbs and started to put in powdered guppy fry food (not sure if they're eating the fry food).

Originally they were in 2-3 gallon plastic container and the bottom did get a bit dirty so I moved them in a 3-4 gallon glass tank with a few live plants and IAL. I'm slowly filling it up using a drip with intercorrelated water and IAL.

I have cling film wrap under the lid and also put a tea tower over to hold the heat and humidity but whenever I feed the heat goes quickly. The temp is around 82-84. I try to siphon 50% of the water after work and replace over night. I feed once early in the morning and once when I get back from work. Usually I siphon before feed.

[aemaki09]

Originally Posted by alunjai

I definitely can't see any ventrals. I heard they end up not growing ventrals if they feed off the bottom cos of the bacteria? My original container ended up being really dirty even after siphoning everyday.

Are yours swimming normally? Mine seem to be struggling to swim and lethargic. Not sure if its something to do with the water temp, water quality or lack in food nutrients? I only have 4 fry left from 50 :(

Jus wanted to say, my fry get fed microworms every day and they don't have an issue, everyone I have looked at for ventrals has had them.
(Just so you don't worry too much about the me part of things)

Now onto your problem. My bottom isn't REALLY dirty, but there's usually some debris on it. I have a ton of plants and they shed/decay and I can't get it all during every vacuuming. So that might be some of your problem, but I don't think so.

My fry are swimming perfectly normal. There is one here or there that may start acting funny, like paralyzed or something, but I've only lost maybe 10 fry total. It was a small spawn, 30ish to start with, have 20 that I can count at one time now.
What are you feeding and how often? What temps do you keep them at? What are your water parameters? How often are you doing w/c's?
I feed mine MW 3x/day. My temp stays at 83-84*. Ammonia and nitrite both at 0 nitrate is 10ish. And I do 2 50% water changes per week with spot cleanings on days the tank looks dirty.

***edit**** didn't see your last post!
Sounds like you are doing everything much better than I am.
My only thinking is that maybe one of the parents have either bad eggs or bad sperm that produced weak fry?

[alunjai]

I can't get hold of MW where I live and bbs always end up at the bottom. Maybe I over feed with bbs and they foul the water. At the moment the new tank is still quite clean and will remove any uneaten food as much as possible. I've added a sponge filter to help aerate the water but the water level hasn't reached to the that level to create the bubbles lol. Wow, you only do 2 50% water changes every week? I use an airline tubing so sometimes I miss bits. The first and second week of water changes was a nightmare sucking up fry etc...

Not sure if they've inherited bad genes but I'm sure they were swimming ok last week? I did have a power cut this week which stopped my heater and bubbler in the bbs hatchery for at least 12 hours. Since then I've noticed all this abnormal swimming pattern.

Originally Posted by aemaki09

Jus wanted to say, my fry get fed microworms every day and they don't have an issue, everyone I have looked at for ventrals has had them.
(Just so you don't worry too much about the me part of things)

Now onto your problem. My bottom isn't REALLY dirty, but there's usually some debris on it. I have a ton of plants and they shed/decay and I can't get it all during every vacuuming. So that might be some of your problem, but I don't think so.

My fry are swimming perfectly normal. There is one here or there that may start acting funny, like paralyzed or something, but I've only lost maybe 10 fry total. It was a small spawn, 30ish to start with, have 20 that I can count at one time now.
What are you feeding and how often? What temps do you keep them at? What are your water parameters? How often are you doing w/c's?
I feed mine MW 3x/day. My temp stays at 83-84*. Ammonia and nitrite both at 0 nitrate is 10ish. And I do 2 50% water changes per week with spot cleanings on days the tank looks dirty.

***edit**** didn't see your last post!
Sounds like you are doing everything much better than I am.
My only thinking is that maybe one of the parents have either bad eggs or bad sperm that produced weak fry?

[alunjai]

They're 6 and a half weeks old and I've noticed ventrals, thank goodness... ha ha... also getting some colour in them now.

I think they're swimming a bit better but they still like to curl up at the bottom. They kind of dart to the top for air then gradually sink (sometimes swim) to the bottom. Is that normal?

I'm wondering if its something to do with their swim bladder?


I'm still considering adding some Epsom salt, as advised by some, as soon as I can get hold of some. Very very small doses of course :)

[December]

I dont know, reading indicates that MW could generate bacteria and could cause them not to grow ventrals...but all three of my spawns...I feed MW and BBS.. and I get about half of them with ventral fins and half of them without...genetic/deformities maybe????

[LittleBettaFish]

Could be that those who didn't develop ventrals spent more time on the bottom of the tank and were therefore exposed to more of the bacteria, which is why some are missing ventrals and some are not.

I don't think it is genetic as I have seen people breeding bettas with no ventrals and none of the resulting fry have shared the problem.

I don't think the way these fry are swimming sounds normal. My fry will usually dart around like maniacs, but they can stay up in the water column without sinking to the bottom of the tank.

Sounds like their swim bladders might have been damaged. I'm wondering, did you feed the fry before the power went out? If the water got too cold and they had full stomachs, it might have slowed down their digestion and caused some issues with the swim bladders? Just a wild stab in the dark, as I did have one female who remained massively bloated because I accidentally switched the heater off and the temperature dropped really low. It wasn't until the water warmed up that she was able to properly digest the food she'd been given.