Help with Bitaeniata sex id

[deco]

Hi all,
finally I got 4 Bitaeniata, they arrived about 20 days ago and now they start to show some colors, occupy coconuts and the bigger ones show themselves at the top.
Can you please help me identify their sex?
I read the other threads on same topics in this board, and got some ideas... but I need some confirmation.

The 4 apisto are: B1, B2, S1, S2 (Bigger 1, Bigger 2, Smaller 1, Smaller 2)

Bigger ones are about 5-6 cm total length, smaller ones are 3-4 cm.

B1: Bigger, lyrate tail, full yellow color, elongated ventral fins: for me it's a male

B2: bigger, same size as B1 but no lyrate, seems truncate tail. This one for me it's impossible.
Tail seems truncated... young male or almost adult female?

S1: smaller, whitish colour, transparent fins, round tail: for me it's a female.

B2: very difficult to get photos, hope are good enough.
strange checkerboard pattern on top. Colour more "grey".
Caudal fin is almost impossible to judge, but it seems truncated. Maybe young male?

Thank you very much

 

[Mike Wise]

A. bitaeniata males > 4cm/1¾": extended front dorsal spines; long ventral fins (beyond beginning of anal fin); obvious lyretail (usually) with a pattern of spots and/or stripes; many blue (Peruvian forms) spots/stripes or large yellow area (Brazilian forms) on head.

A. bitaeniata females > 2.5cm/1": front dorsal spines with no or only very little extension; ventral fins shorter (to beginning of anal fin); round to squared off caudal fin with no caudal markings (or very faint); much fewer blue markings (Peruvian) or much less yellow (Brazilian) on head.

 

[deco]

Thank you Mike, as always, quick and precise.
So... could be:
B1 male
B2 female
S1 female
S2 too small
?
Do you agree?

 

[deco]

Sorry the last group of 3 photos, marked as "B2: very difficult to get photos", should instead be "S2: very difficult to get photos"

 

[Mike Wise]

Yes, it looks like all but the first fish are females.

 

[deco]

Thanks

Yes, it looks like all but the first fish are females.