I have never had my ponies fight! Most of my seahorse keeping has been in trios however, 1 male with 2 females.
1 of my females is one of my original seahorses and she has to be over 5 years old. Although she is quite active I don't think she is producing eggs anymore.
I always had 2 males since the beginning, now i have 3 since last november.
It might be about the number or females available...
Jetlag was competing with Voodoo for the same female (Marmite).
Later on, i lost Voodoo (so far the only seahorse i v lost) to bubble gaz deasease (bubbles under the skin in the pouch, so it was not obvious). He always had prolapsus problems also. 8 days of Diamox didn t saved him.
Then i added a piebald female, another female, then another male (these 2 paired almost immediatly)
For my last birthday i had another piebald male.
So right now i have 3 males and 3 females but one of the females (the last that came in), bought in avril 2018, never grew. She is smaller than my 6 months old offpring. The other female i added a few weeks after her was smaller and now she is maximum adult size, while the small female piebald still stay small...
She eats fine, have eggs, behave normally... She just don t grow. Could be linked to some genes of piebald...
On this picture you can see the "dwarf" piebald female (i m holding her) compared to 5 1/2 months old juveniles.
You can also see the female that i added after her and which was smaller than her (pale grey)