Swollen Bellies On Newborn Guppy Fry

[perogi]

i've been breeding guppies for a year now but recently had a couple newborns that had really swelled tummy's as soon as they were born. I seperated them and kept watch...i can't tell if it went down at all or not but what's caused this??
are they going to be ok or is it a defect? can i prevent it?

 

[5teady_2012]

When some fry are born, some have a bigger yoellow sack underneath them compare to others, some dont even have one..

Is it yellow?

 

[perogi]

pale yellowish...looks like the rest of their skin

 

[5teady_2012]

Its a yolk sack m8, that yolk sack is basically what it will feed on for the next 24 hours (approx)

Do not feed the fry until the sack has gone...

After this make sure you feed them every 2-3 hours, 3-5 times a day

Good luck and congrats

 

[dunchp]

Yup that is right.

Fish such as goodeids and some poeciliids practice high levels of matrophy (the passing of nutrients from the mother to the developing young). Fish such as guppies do not. These fish basically store the eggs internally until they are ready to hatch and pass very low level of nutrients from mother to young. In these fish the eggs have to contain sufficient nutrients to see the foetuses through until they develop.

The yolk sac is the left over nutrients when the fish is born and will depend upon how close to full term the fish are when born. A yolk sac is normal and should be used up in 12-24 hours or so; it is also normal if a fish does not have a yolk sac so don't worry about it.

5teady is right about the colour, although it is possible that you cannot see the colour through the flanks of the fish.

 

[perogi]

Really? I had no idea livebearer babies had a yolk sack. So many that I've seen born never had it so thats why it threw me off.

 

[dunchp]

Really? I had no idea livebearer babies had a yolk sack. So many that I've seen born never had it so thats why it threw me off.

Only in Poeciliids.

Goodeids have an umbilical cord structure called a trophotania.