Odds of Getting a Male/Female Pair from Juveniles
By Jennifer Macke
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Since juveniles cannot be sexed, how many do you need to have in order to have a good chance of having at least one pair? If you take a truly random group of juveniles, your odds are as shown below. There are some factors that may cause you to get non-random distribution of genders. These factors are listed below. |
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| Number of juveniles | Chance of having at least one pair |
| 1 | 0% |
| 2 | 50% |
| 3 | 75% |
| 4 | 88% |
| 5 | 94% |
| 6 | 97% |
| 7 | 98% |
| 8 | 99% |
Some factors may cause you to get a non-random sex ratio.
- If you get only the largest or smallest of the juveniles, you may tend to get mostly one sex.
- If you choose a group with one particular color pattern, or the most aquatic individuals, you may be predisposed to getting all one sex.
- Some species have a phenomenon of sex reversal when the offspring are raised at unusually high or low temperatures. In these cases, the offspring may be predominantly of a single sex.
© Jennifer Macke, September 2004