Everyday tool

Guppy Breeding Simulator

Explore how a guppy population changes under different brood, survival, maturity, and separation assumptions.

1–12-month model; not a forecast of births or safe stocking

Explore a breeding scenarioChange brood, survival, maturity, and separation assumptions.

GUPPY

Adult males

fish

Adult females

fish

Fry per brood

fry

Brood interval

days

Fry survival

Female fry

Maturity

months

Projection

months

Separate males and females

Assumptions matter

Each adult female is assumed to brood at the same interval. Surviving fry mature at the selected month and may breed afterward unless separated.

Population projectionScenario, not a promise

After 6 months1,722 fishAdults 138 · Juveniles 1,584

Now6—

1 mo50+44

2 mo94+44

3 mo138+44

4 mo424+286

5 mo952+528

6 mo1,722+770

Later generations also reproduce

Actual numbers can be far lower because brood size, survival, maturity, sex ratio, fertility, predation, and care conditions vary.

Set adults and brood assumptions
Enter male/female adults, brood interval, and fry per brood. Every adult female is assumed to reproduce under the same conditions.
Include the next generation
Set survival, female proportion, and maturity age. Surviving fry may later join the breeding adults and accelerate growth.
Compare separation timing
Choose a separation month to stop new breeding from that month in the model. Compare the resulting adults and juveniles month by month.

A worked example

This assumes no separation and all starting adults remaining in the model.

Tools that work well together