Disappearing male guppies

[PattysAquatics]

So I’m at a loss, this summer I set up a 100 gallon Rubbermaid tub outside with plants 3 goldfish about 4 inches and a koi about 3 inches. I put in 3 pairs of red dragon guppies. Within days all but one female guppy was all I could find. Periodically through the summer I would add another male and they would keep disappearing. Thought it was weird but figured a bird or something kept getting them. Well I live in Wisconsin so I brought the tub into my basement for the winter and transferred the fish to it. I added another male guppy in hopes of breeding over the winter and the male is nowhere to be seen. I looked all over the tub and there was no body. I added a bunch of young Endler and different guppies at this point (all small) and they are still alive and thriving so I added another adult male red dragon guppy and the next day it is missing again. I’m at a loss for what is happening to them. I have a big female red dragon guppy, 3 goldfish 4in , 1 koi 4inch , 4 coryies , a few albino bristlenose plecos and a bunch of young Endler and guppies stocked in the tub. I wouldn’t think any of them would eat an adult guppy. Anyone have any ideas where they are disappearing from?

[Patrick_G]

So strange! I’m pretty sure my outside Goldfish would swallow a guppy if it would fit in their mouths. They’re not aggressive, but they are opportunistic. I guess the mystery is why only your male Red dragon guppies are disappearing. 

[Guppysnail]

I’m sorry you are losing fish. Just a thought. Adult male guppies are typically slower swimmers. Juvenile guppies and endlers as well as female adult guppies are stronger swimmers. My male guppies are also nosier and less likely to run away from other fish. 
Im going to hazard a guess your goldfish is a strong enough swimmer to catch the males but not the rest. Males being slightly smaller may also make them bite size. Endlers and juvenile guppies are quick and tend to be more skittish when larger fish are near where adult male guppies all want to be tank boss so less likely to run when the goldfish gets in the same area as they are. 
Edit add: as your goldfish grows more and more fish will soon become snacks most likely. 

Edited December 14, 2022 by Guppysnail

[PotatoFish]

On 12/14/2022 at 8:58 PM, Guppysnail said:

I’m sorry you are losing fish. Just a thought. Adult male guppies are typically slower swimmers. Juvenile guppies and endlers as well as female adult guppies are stronger swimmers. My male guppies are also nosier and less likely to run away from other fish. 
Im going to hazard a guess your goldfish is a strong enough swimmer to catch the males but not the rest. Males being slightly smaller may also make them bite size. Endlers and juvenile guppies are quick and tend to be more skittish when larger fish are near where adult male guppies all want to be tank boss so less likely to run when the goldfish gets in the same area as they are. 
Edit add: as your goldfish grows more and more fish will soon become snacks most likely. 

Most definitely this... When Loppy, my goldfish, was alive, she was a total guppy nommer. If the guppy wasn't fast enough, it was snack enough.

The only male guppies she wasn't catching were the ones without big tails.

[PattysAquatics]

Thank you, I guess I didn’t realize that goldfish would eat them. Then I definitely will stop sacrificing my male guppies to the goldfish and that would also explain where all my shrimp went I put in there as well . Live and learn I guess