swordtails dying

[Tostada]

My main 30 gal. tank has been cycled for a month. All the parameters are good and I haven't had any real problems with fish losses.

I had 5 panda corys. All of them were very small, and one of them never ate anything and just sat there, then died after a week. Other than that, the only losses I've had were swords (I lost a betta in another tank but that's a different story).

So, I had 6 Velvet Wag Swordtails (2 males, 4 females), and two females died a week after I got them. It seemed a little strange to me, because the only other fish in there at the time were 3 danios. I replaced the females and everything has been fine for 3-4 weeks.

Now I've got 7 rasboras, 4 panda corys, 1 gourami and 3 ottos in there. Everybody keeps to themselves and gets along, except the gourami nips at the ottos and swords now and then (he seems to have an "angry day" about once a week). I could understand if I got up one morning and a Cory was missing its tail or an otto was dead. I would blame the gourami. But that's never happened. Instead, I had a female show up dead about 4 mornings ago, then a male dead about 2 mornings ago.

I also have a couple shrimp in there which are about 2.5" long (sold as ghost shrimp but probably not), but I've never seen them get aggressive with anybody. Of course, they're always chewing on the corpse when I find it in the morning.

I've noticed that all the livebearers in Petsmart say "requirs aquarium salt," but people hear say that's not necessary. I went and put 3 tablespoons of aquarium salt in there anyway after today's PWC (half the recommended amount on the box).

So, now I'm down to 3 females and 1 male. I think all 3 are pregnant (one might be, one definitely is, and one is going to give birth at any time). It's surprising to me that the female who died was the only one who wasn't pregnant.

Also, I've noticed that one of the females is lighter colored on the bottom in front of her gills, but not at the edge of the gills ... doesn't really look like a parasite or ich or anytying. I'm not sure about what fungi looks like ... it's just weird that it's just that section that's a little lighter.

I just find it suspicious that I've lost a few swords. I've always heard that rasboras are sensitive and ottos are very sensitive, and they're all OK.

 

[Guest]

are your swordtails "shimmying" or wobbling in place?

 

[Zagz]

Moved to unhealthy fish.

First your cories and your shrimp do not like salt. I would do a 50% pwc to remove the salt, and then do another 50% in a couple of days.

With your swordtails, have they had any symptoms like cottony white patches? Bloating? Or do they just seem fine one day, then gone the next?

 

[Alshain]

This may sound like a dumb question but its happened to me. Are you sure you have correctly identified the sex of all the swordtails that died? The sword extension on the tail isn't a good enough method as this does not develop right away and sometimes slower than other fish.

The only true way to tell is from the gonopodium, and even then some swordtails develop that late. It is possible you had too many males fighting over a few females. While they are docile community fish, almost any fish will fight for mating rights.

2 males for 4 females is already an improper balance, you need AT LEAST 3 females per male, and if one of your females was really male then you were really off balance. Another possibilty is if you really had 4 females and 2 males, the female that died was overstressed from so many males and the other 2 males fought resulting in the dead male.

From your description, I haven't read anything that would indicate sickness. Color variations among swordtails are incredibly common. Your one light colored fish could be a slight hybrid or mutation. That does not make me suspect anything out of the ordinary.

 

[Tostada]

Moved to unhealthy fish.

First your cories and your shrimp do not like salt. I would do a 50% pwc to remove the salt, and then do another 50% in a couple of days.

With your swordtails, have they had any symptoms like cottony white patches? Bloating? Or do they just seem fine one day, then gone the next?

I guess I'm a little too new at this to tell if they seem bloated ... although I'm pretty sure two of them are just pregnant -- unless they're severely bloated.

One of the females has some lighter patches in front of her gills, and I might call that "cottony," but it's not really anything fungus-looking to me. It's definitely not sticking up at all. The ones that died were the larger male and the non-pregnant female. Odd, really ... because the male that survived had previously had his "sword" bit off by the other one (but it's grown back).

This may sound like a dumb question but its happened to me. Are you sure you have correctly identified the sex of all the swordtails that died? The sword extension on the tail isn't a good enough method as this does not develop right away and sometimes slower than other fish.

I'm nearly positive I'm correct about which ones are female. None of them are that young, and the ones without swords have the fanned-out anal fins.

I just think it's really odd. I thought the swords were supposed to be some of the heartiest fish I had.