Age affects what is visible
Body shape and coloration can be difficult to compare in young shrimp. Lighting, viewing angle, and individual variation also affect the impression.
A pale or narrow animal is not automatically male, and a rounded shape alone is not proof of a female.
Observe a group over time
Use repeated photographs under similar conditions and look for more than one trait. A carrying female is more direct evidence than a quick visual guess.
Avoid catching shrimp for routine sexing. Handling adds stress and may still leave the identification uncertain.
Plan with uncertainty
For a breeding project, start with a group and let the colony mature rather than expecting a perfect sex ratio from visual selection.
Record estimates as likely or unknown. This is more useful than reporting precise counts that the evidence cannot support.
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.