questions about Gambusia

[Sgooosh]

hello, i have a few questions about gambusia
1. what causes them to be melanistic? i have never seen one before. are they rare?
2. how can i tell the difference between affinis/holbrooki
3. is it possible to try and bring out traits by breeding like how i do with poecilias?
4. how can I make sure that outdoor pond fish will not have diseases when I bring them inside?

 

[emeraldking]

Hi again,
1. Only the Gambusia holbrooki can be melanistic. This means that there are also non melanistic specimens of the G.holbrooki. A melanistic mosquito fish has got more melanophores (dark color cells). A melanistic G.holbrooki is not rare.

2. Both gambusia species don't occur in the same waters. Both species are almost the same. Just a few details where they differ. The gonopodium differ in structure(minor difference) but they are still compatible to crossbreed with another. Only the G.affinis can show a slight (till really present) a yellow splotch on the belly and/or the chest area which a pure G.holbrooki won't show.
3. Selecting and linebreeding does make it possible to breed for a certain trait.
4. You can't be sure. Do realize that an outdoor environment has got a different bacterial culture than those kept indoors. But you can put them in quarantine first.

When I read the title, I was asking myself which Gambusia is meant by this? For there are also other gambusia species than just the G.holbrooki and G.affinis.

 

[Sgooosh]

Hi again,
1. Only the Gambusia holbrooki can be melanistic. This means that there are also non melanistic specimens of the G.holbrooki. A melanistic mosquito fish has got more melanophores (dark color cells). A melanistic G.holbrooki is not rare.

2. Both gambusia species don't occur in the same waters. Both species are almost the same. Just a few details where they differ. The gonopodium differ in structure(minor difference) but they are still compatible to crossbreed with another. Only the G.affinis can show a slight (till really present) a yellow splotch on the belly and/or the chest area which a pure G.holbrooki won't show.
3. Selecting and linebreeding does make it possible to breed for a certain trait.
4. You can't be sure. Do realize that an outdoor environment has got a different bacterial culture than those kept indoors. But you can put them in quarantine first.

When I read the title, I was asking myself which Gambusia is meant by this? For there are also other gambusia species than just the G.holbrooki and G.affinis.

where we live, our gambusia have a very pronounced "teardrop".
perhaps I will be able to find out once It gets warmer in the summer so i am able to wade in the river and net them
I will send a picture if so
does the first picture of hoolbrooki have black fins or was the picture taken on a background

most likely There is Affinis, since I am in western US
"They based their conclusion, in part, on the importance and size of the mosquito control program in California, and the central role mosquitofish played in those attempts. However, Dill and Cordone did admit that there was no real proof that G. holbrooki became established in the state."(nas.er.usgs.gov)

 

[emeraldking]

does the first picture of hoolbrooki have black fins or was the picture taken on a background

Dark fins.

The black vertical bar on the eyes "can" occur in both G.holbrooki and G.affinis.

 

[Sgooosh]

Dark fins

nice, i;ve never seen any photos online like that

 

[emeraldking]

nice, i;ve never seen any photos online like that

I've got mine together with my butterfly splitfins. In both holbrooki and affinis, females and males can phenotypically differ from another. Even dark finnage.