Sumo PRL (Pure Red Line) - Male or Female?

Finding a local fish shop that sell a quality shrimps with reasonable price is not that easy. Once you found that shop and thinking to get few male and few female shrimps so that they can breed, the next question coming into your mind is, how am I going to differentiate the male and female? If you getting a large quantity of them, more than 10, there's no doubt that there will be a mixture of male and female, but if you get less than 5, there's chance that none of them is male or female. Beside be able to seximg them is also important when you go into selective breeding 

Sexing attributes

PlanetInverts has a very good guideline (Link) on how to sexing them. You can go to the link to get the detail explanation and diagrams. I would just summarize the attributes that can be use to sex the shrimps 

From PlanetInverts

1) The "Saddle"
Female shrimp has a "saddle" (or miniature undeveloped eggs in the ovaries) appear on the back of the shrimp, behind the head.

2) Curved Underbelly

To carry and protect the egg, the female developed more curved underbelly.

3) Size & Coloration: 

Rule of tumb, the female is typically larger, darker, prettier than the male. 

Learning from the owner of a local fish shop.

4) Head ratio

Female shrimp have larger head, and a larger head to body ratio compare to male

Sexing PRL

I'll put this theory into use to differentiate the gender of my Sumo PRL. Here's 4 pieces of specimen, let's take a look and analysis (or guess) the sexes of them. I'll do some speculation as well but the sexes will remain mystery until it berried (carry eggs) 

Sumo PRL 1:

Sumo PRL 2:

Sumo PRL 3:

Sumo PRL 4:

Analysis and guess

• PRL 1 is a male and PRL 2 is a female
• Compare with PRL 2, the PRL 1 has smaller head to body ratio. 
• PRL 2 have a more curved underbelly compare with PRL 1 as well
• PRL 3 is a male
• It has a smaller head to body ratio.
• It look slim and has no underbelly
• PRL 4 is a female
• It has more curved and fat underbelly  

Summary
From the sexing attributes that I manage to gather so far, I can't find a definite answer to tell us that particular shrimps is male or female. Most of the sexing attributes is based on the comparison between shrimps. Although there's an exception on if saddle appear than we can confirm it's a female, saddle is not able to be noticed with most of the Caridina species due to it solid colour on the back of the shrimps head. You may have different guess, speculation than me. The seasonal shrimps keeper or shrimps breeder may even have the definitive answer. So, to be able to sex them correctly, you need to be experience enough on shrimps keeping so that the comparison (based on the shrimps you approach before) can be clearer. And what's the answer for my PRL sexes? I don't know for now but will definitely update this post once they berried