Guppy Runts?

[malvo]

Of a brood of about 40 guppies, 7 are hardly growing AT ALL.
At 6 months some are only about the size of 3 week old fry. They are showing a little color but otherwise look like babies.
Their growing conditions were not ideal, but their siblings quickly grew to beautiful healthy adults.

I am not asking for a solution to this, just wanted to share the odd experience. I will keep them and see how they turn out long term.

 

[PlasticGalaxy]

Wow, those guppies are FAT! They almost look like platys. Strange that this has happened though... Seems pretty common though.

 

[Colin_T]

It's either caused by lack of food, poor water quality or genetics.

 

[AdoraBelle Dearheart]

Interesting!

Not that long ago I had a female guppy give birth to two fry, a male and a female. Might have been more, but it was a community tank, so only two made it to a safe size. It was her first batch too, so I wasn't expecting her to have many.

Those two ended up stunted. Otherwise normal and healthy looking, the male looks like a mini-me of his dad, only a third of the size.

The fry produced by the same parents later on, larger batches, all grew up normally, and the stunted two had the same conditions as all the others - except that I was battling worms, and had to medicate the tanks when those two fry were newborns. I suspect the meds stunted their growth.

When you say their conditions were less than ideal, was it something like that? I didn't like to medicate the tank with newborn fry in it, but you know guppies - there are always newborn fry! And you can't mess about with camallanus worms, had to medicate all the tanks at the same time.

I kept the two, in male/female only tanks, will just them live out their lives here, like you're doing. Happens sometimes.

 

[Colin_T]

The babies could have had intestinal worms, which would stunt their growth too.

If the parents weren't well fed before breeding, they would have produced inferior gametes (eggs & sperm) and this will lead to smaller weak offspring.

Female livebearers should be fed well when gravid (pregnant) because some nutrition is taken by the developing young. However, most is obtained from their yolk sac

 

[malvo]

My statement that "conditions were not ideal" is because:
* Rearing tank is 2.5 gal, small bubble up filter with just a pad inside it for 40 fry and 3 adults.
* Normal size fry were not removed from the tiny tank until about half grown so tank was pretty crowded.
* I do not check parameters. Diligent fish keepers will flame me!
* Often I am gone 5 AM to 8 PM so sometimes they only get fed late at night.


BUT....................
All the other fry grew like weeds.
The very large female in the photo is from the same brood and was kept in the tank for about 5 or 6 months till she had her first brood. That was three weeks ago and her babies are now the same size as the runts.

So, I suspect genetics is to blame.

I am curious to see:
Will they eventually grow? How big?
They have some color but will they fully color up?
Will they develop sexually?

No matter what, they will live happily ever after in the tiny tank.

 

[itiwhetu]

When raising fry the more water you have the better. Huge tanks are what is required to raise fish successfully.