- Day 1 to Day 3 – The “Yolk Sac” Stage
- Day 4 – First Feeding (Infusoria)
- Day 7 – The “Eyed Up” Fry (First Signs of Color)
- Day 10 – Introducing Microworms
- Day 14 – The “Swordtail” Stage (Fins Developing)
- Day 21 – First Brine Shrimp Feeding
- Day 28 – The “Juvenile” Stage (Looking Like Adults)
- Month 2 – Sex Differentiation (Color Changes)
- Month 3 – The “Sub-Adult” Stage (Ready to Breed?)
- Month 4 – First Spawning Attempts
- How to “Measure” Growth – Tracking Length and Weight
- The “Growth Curve” – What’s Normal and What’s Not
- Why Some Fry “Outgrow” Others (Dominance)
- The “Stunted” Fry – Causes and Remedies
- How to “Photograph” Fry at Each Stage
- The “Color Development” – When Do They Get Color?
- Why Pseudomugil Fry Are Tiny (2mm at Hatch)
- The “Transition” Stage – When to Move to Larger Tanks
- How to “Sex” Fry at 6 Weeks (Venting Method)
- The “Male” vs. “Female” Growth Rates
- Why Some Fry Are “Cannibalistic” (and How to Prevent It)
- The “Fry Diet” – Adjusting as They Grow
- How to “Grade” Fry by Size for Separation
- The “Second Week” – What to Expect (Development Milestones)
- Why Some Fry Develop “Curved Spines” (Nutritional Deficiency)
- The “Fin Development” – When Do Fins Fully Form?
- How to “Enhance” Growth with Frequent Water Changes
- The “Temperature” Effect on Growth Rate
- Why Some Fry Are “Premature” (Weak Hatchlings)
- The “Survival Rate” – How Many Make It to Adulthood?
- How to “Document” Each Fry’s Development
- The “Grow-Out” Tank – When to Transfer
- Why “Crowding” Slows Growth
- The “Feeding Frequency” – Reducing as They Grow
- How to “Wean” Fry onto Flakes
- The “First Color” – Spotting the Early Signs
- Why Some Fry Are “Pale” (Stress or Genetics?)
- The “Third Week” – The “Active Swimmer” Stage
- How to “Identify” Deformities Early
- The “Breeding Size” – When Are They Ready?
- Why Some Species Take 6 Months to Mature (Pseudomugil)
- The “Growth Log” – Tracking Each Batch
- How to “Select” the Best Fry for Future Breeding
- The “Culling” Stage – Removing Weak Individuals
- Why Some Fry “Hide” (Behavioral Development)
- The “Lighting” Effect on Fry Growth
- How to “Fatten” Fry for Fast Growth
- The “Juvenile” Coloration vs. Adult Coloration
- Why Some Fry “Sparkle” (Iridescence Development)
- The “Final” Stage – Full Adult Size

Killifish Breeding