Need more input! (Nerite snail sexing)

So I have 3 nerite snails right now. The first two I got were lighter colored, smaller, and excellent at eating algae. Never laid eggs in a year, so I assume they are males. my third nerite I got later on, she is darker, twice their size (all are full grown), sucks at keeping tanks clean, and lays eggs (hence how I know she is a girl!). Obviously my observations are limited to just my own snails, so I was wondering if anyone could back up (or refute) my findings.

Females:
Darker, larger, worse at cleaning, egg laying

Males:
Small, lighter colored, excellent cleaning crew, never seen an egg

 

I have a single nerite in my 10 gallon tank and she (definitely she) keeps it spotless. I haven't ever had to scrub the glass or decorations. Perhaps you've just got different species and it could be coincidental that you've got two males of one species and a female of another species? Then the size and different coloring and even cleaning ability could very well be due to species rather than gender. Just a thought!

 

I have a single nerite in my 10 gallon tank and she (definitely she) keeps it spotless. I haven't ever had to scrub the glass or decorations. Perhaps you've just got different species and it could be coincidental that you've got two males of one species and a female of another species? Then the size and different coloring and even cleaning ability could very well be due to species rather than gender. Just a thought!

Good point! This is why I wanted more input what does your female look like?

 

Good point! This is why I wanted more input what does your female look like?

She is a dark amber color with black spots. I believe she is a tiger nerite, but there is still so much ambiguity around differentiation and sub-species that I guess "tiger nerite" is nothing more than a broad category!

 

This might not be 100% helpful, because I don't know the genders of my Nerite snails. I've had them about a week. I can say that in that week, the Zebra Nerite has eaten algae almost non-stop. The Red Racer Nerite has escaped the tank twice & I haven't seen him/her eat anything but the Snail Jello I put in the tank (but, I place him/her onto the "Snello"). So, maybe it's a difference in the Nerite type?

 

Just lift up their skirt to check.

But honestly i dont believe nerites are sexable.