Why are some species bold and others hide ?

[anewbie]

This is on the surface a silly question but i was kind of curious if there is an explanation for why some species are extremely bold and other hide all day long. Two examples (both wc) that I own are:
D50 - never hide - have to shoo away when working on the aquarium - somewhat innately curious what i am doing. Not really sure curious is the correct word since i don't think fishes think in those terms but that sort of the best explanation i can give for the behavior.
pucallpaensis - even after a year the male will run an hide if i approach the aquarium - wants nothing to do with me - the female as seems more typical for most species are quite bold and the frys also enjoy a good feeding (they are around 2 months old).

 

[MacZ]

D50 are relatively big and according to an article by Uwe Römer they hail from relatively open blackwater creeks and they are supposed to have relatively high intraspecies aggression, while Apistogrammoides are quite small, timid and tend to live reclusive in thickets of floating plants.

This tells me:
D50 can afford to be more outgoing, as there are likely fewer predators and the habitat underwater is more open, providing easy escape routes for subdominant fish, while the emerse habitat will likely have little to no predators from above like herons. On the other hand this kind of habitat requires the fish to be especially wary defending a territory in such environment. Something that also breeds a more outgoing personality.
Apistogrammoides can not afford this. They seem to live in more open habitats when it comes to the emerse dangers, if the plant-relationship is as close as described. Additionally they are smaller, which means more other fish are able to prey on them.

And this is why I find researching the habitats so exciting.

 

[anewbie]

D50 are relatively big and according to an article by Uwe Römer they hail from relatively open blackwater creeks and they are supposed to have relatively high intraspecies aggression, while Apistogrammoides are quite small, timid and tend to live reclusive in thickets of floating plants.

This tells me:
D50 can afford to be more outgoing, as there are likely fewer predators and the habitat underwater is more open, providing easy escape routes for subdominant fish, while the emerse habitat will likely have little to no predators from above like herons. On the other hand this kind of habitat requires the fish to be especially wary defending a territory in such environment. Something that also breeds a more outgoing personality.
Apistogrammoides can not afford this. They seem to live in more open habitats when it comes to the emerse dangers, if the plant-relationship is as close as described. Additionally they are smaller, which means more other fish are able to prey on them.

And this is why I find researching the habitats so exciting.

I do wonder if is strictly habitat - changing to non dwarves - my festums are 'fraid of their own shadows but it takes a major storm to frighten the angels. Both fishes typically occur in the same biotope - i'm not saying your explanation is inaccurate - it is likely dead on for the two species i mentioned though i'm waiting to see ift he tank raise ones have their parents same behavior (sadly this is a multi year project give the growth rate of the frys); the festum i haven't quite figured out - the small females are quite aggressive at times - also true of angels and that might be the reason the males are always on edge (I have 2 likely females and 7 males - juding from size alone). They are currently stuffed in a 120 but they will be getting the 450 when i move in 5 weeks.