Disappearing Male Guppies

[Darkfung]

i'm having a problem keeping male guppies alive in my tropical tank. I've had several batches of fry birthed and the only ones who ever make it past about 8 months old are the females - now I'm down to an all female guppy population of very healthy large females but my last male disappeared a week ago. Once the colours are in and the tail is a decent size they just vanish - and they aren't even that spectacularly coloured - in fact they are basically a dull yellow.
The tank also houses 5 harlequins, 1 small catfish, 3 blind cave fish, 2 orange platies and 2 rainbow fish - all are mature big healthy specimens that I've had since they were infants. I'm seeing no bodies - the guppy male just vanishes overnight - no illness etc.
Any ideas what's happening here ? I'm loathe to buy any new males now .....

 

[ZoddyZod]

how big are the rainbows?

 

[Darkfung]

how big are the rainbows?

hmm... I'd say about 10cm long, 5cm wide - I've had them for over 3 years so I'd guess they'd be considered adult. they seem quite sedentary normally and don't seem to chase anything ...

 

[ZoddyZod]

I'm not at all familiar with rainbows, but they sound large enough to take on a guppy.

Hopefully someone with rainbow experience will comment.....

 

[JohnDyer]

If you have any sort of shrimp or snails, they'll process dead fish VERY quickly, skeleton and all. I've noticed missing guppies too, but didn't realize what it was until I caught a shrimp chewing away at one. It only took around 45 minutes from complete body to nothing left.
Fish will nibble at it too, if you give them a few hours I'm sure the fish can clean up a small guppy body.
The only other thing I can think of is if they get stuck in some ornament. One of my larger angelfish (5 inches long) got stuck sideways in a big upside-down seashell, I couldn't find it for 3 days. Really messed up my water chemistry, that's for sure. You should test for ammonia, if you get a lot of it, there's probably a rotting body somewhere.

 

[Darkfung]

I don't think you are understanding - it is only male guppies that are disappearing .... out of all the births I've had no male has survived past about 6 months but the females survive and thrive. I get that the body is probably devoured by snails but do you think this is because another fish is killing them or because of some kind of chemical imbalnce in the water that causes males to die (which sounds unlikely to be fair).

 

[littlenemo]

There prob getting eaten by another fish in your tank I had the same problem with mollies. I had a heavily planted tank so could never see what was going on. So I rescaped my tank took most of the plants out. And noticed my garamies bulling a small mollie.

 

[MBOU]

Its the cave fish. Blind cave fish are savage with long finned fish. To put it mildly...

 

[Darkfung]

Its the cave fish. Blind cave fish are savage with long finned fish. To put it mildly...

hmm - you know I once saw one of the blind cave fish with a half eaten fish in its mouth - too big to swallow - yes, it was a Guppy ...
But how can they even see to chase or harm a fish - they are blind?

I would have never thought of them as the culprits - the Rainbow fish yes .....

 

[MBOU]

Rainbow fish arent aggressive.

Blind Cave Tetras are known for their aggressive natures. They don't have eyes because they come from places that are so dark they dont need them, don't you think they have far more advanced senses elsewhere that allow them to hunt? If anything that makes them all the more dangerous as they will happily hunt the other fish at night when they are asleep and drifting along slowly as it makes to differents to the blind cave fish!

Some species of blind cave fish lack eyes completely, but most have small rudimentary (non-functioning eyes), that are grown over and covered in scales. Having originated from deep underground, the constant lack of sunlight in their environment made vision unnecessary. Even though they are sightless, they manage to go about a “normal” fish routine of hunting, sleeping and exploring, and have an amazing ability to navigate in their environment. All have tactile organs on their head and sides, that are extremely sensitive to touch, allowing the fish to feel what it cannot see. They move through the water with this “radar” system, that allows them to detect movements of prey and predators. The blind cave fish’s lack of vision has also led to a heightened sense of smell. They use this along with their ability to detect water movement to find their prey, copepods, cave snails, isopods and amphipods.

A. mexicanus only grows to a length of 12 cm (4.7 in) in the recommended minimum of 30 US gallons. The blind cave tetra is a fairly hardy species. They are not picky on food, as they will eat anything from standard flakes to sinking carnivore pellets. Their lack of sight does not hinder their ability to get any and all food before it hits the bottom. They prefer subdued lighting with a rocky substrate, like gravel. It is recommended that the tank mimic their natural environment, so artificial or natural rock is highly appreciated. They become semi-aggressive as they age, but are by nature schooling fish, and a group of at least three is a good idea. However, it isn't imperative, as they can be kept as a single specimen. As stated earlier, they can get to their food rather swiftly, even more so than fish with the ability to see, so they aren't really good for a community, but one is OK for a semi-aggressive community. They are also incredibly fast, so catching them with the net is a chore in itself while conducting maintenance.

Pretty much sums it up... lol

Blind cave fish apparently compensate for having no eyesight by biting everything they bump into - which is pretty much everything.