Sexual dimorphism, Hypsophrys nicaraguensis

[tiger15]

in term of sexual dimorphism, few are as extreme as Nic. I am not talking about just the color difference, as Nic are the few exception in the cichlid world that females are more colorful than males. The size difference between male and female Nic is extreme. I raised these Nic from juvies of the same size. The matured male is now 8 inch, versus the females that are barely 4 inch. I am not sure if this is an anomaly or typical of the species. Another notable difference is females initiate the courtship, which resemble Kribensis behavior.

 

[PhishMon84]

Nics are a great fish- seemingly under represented.
The only other fish that come to mind, where the female is more impressive than the male, are those of the SA genus mesoheros.
My female atros and Female festae are stunning.

 

[duanes]

Many Central Americans have females that are more colorful than males, or at least have more melanin.
Beside the Nics
male

female

Parachromis motaguense
male

female

In the Nosferatu the females tend to be much darker, below bartoni
female

male

Nandopsis
female haitiensus in the lower portion

Nandopsis tetracanthus, female more in the foreground

 

[tiger15]

But not the huge size difference.

 

[duanes]

although size may often be related to age differences, in most of my successful spawning pairs, my male have been 1/3 to 2/3s larger than females of even the same age.

 

[Toiletcar]

Female salvini are usually more colorful though depends of the catch location.

 

[Roberto G]

Old reply, but I've heard that females usually stop growing after their first spawn. Is this true? If that's so that'd explain the huge size difference shown on some of the pics on the post.

 

[tiger15]

Old reply, but I've heard that females usually stop growing after their first spawn. Is this true? If that's so that'd explain the huge size difference shown on some of the pics on the post.

They don’t stop growing, but once females start spawning and be allowed to continue, the growth rate will slow down as energy is diverted to making eggs. If you remove the males to deprive the opportunity of the females to spawn, the growth rate will return to normal. I’ve witnessed it many times raising cichlid juvies and females removed from the males always grow faster.

Male’s growth rate doesn’t seem to be affected at all as sperm is cheap. The subordinate male that is deprived of breeding opportunity will not catch up from behind to outgrow the dominant male that owns the right to breed.