Mosquito fish dont have any color, they are mainly tan or grey in color, and they are thinner and longer looking.
The Gravid female will have the dark "gravid spot" in front of her vent. I can however assure you that if there has been a male in the same tank with a female guppy for any reasonable length of time she will be gravid.
The female guppy will develop a dark spot on the side of her belly during pregnancy. As the pregnancy progresses, the spot will grow darker.
A female guppy has a darker brown line that is visible through its body. The male has a very light brown line.
you can't
You can tell by it's anal fin that is located at the bottom of the fish. If it is a male guppy it will have a gonopodium it looks like a backwards point, and if it is a female it will have a anal fin that looks like a backwards Chinese or Japanese fan. I really hope this helps if not post a photo ok
With a guppy you need to look at the gravid spot. This is a dark spot in the fish's belly. A large gravid spot indicates the fish is likely to be pregnant. You can tell how pregnant the fish is by how large the spot is. Sorry I have no experience with other species.
Feeder fish, How do you tell male from female of the?
it will have a fan tail by the begining of its tail, they are generally bigger than a male and males have alot more color than a female.
When your female guppy is pregnant you can't tell by it's size. You have to look at it's gravid spot. Which is right behind their stomach and the tail. It's right around the butt of the guppy. It takes about a month for the babies to be born. Plus you can not stress out your the pregnant fish.
Well they are called female mosquito's. Normally it is impossible to tell the difference between the female and the male - depending on what species it is.The BIG one to watch out for it the female Anophelesmosquito, which is the one of the vectors of the Malaria parasite (Plasmodium)
The female guppy will be very large and will have a gravid spot near her anus. But when she is ready to give birth she will be very still and huddling near the heater in your tank.
a mosquito fish will jump out of the water to get a bug and usually a rosey red or minnow as you called it they usually dont a mosquito fish usually has stripes and a rosy red is pretty small like a tetra and is usually pink in color and you can see their insides.