Strange problem: Ameca males dying?
Illustrator posted: 11.05.2011
Dear all,
Am i the only one who encounters strange and unexpected problems?
Some weeks ago i removed the older Ameca splendens from my aquarium, so that half-grown ones can grow out and replace the breeding fish. Since then, male Ameca start dying, one by one. By now at least 5 out of 7 died. Symptoms are a slight discoloration which is caused by opaque discolouration of muscle, then gradual lack of balance, so very non-specific. Nitrite & nitrate are non-measurable and pH is around 8 (sera-testkit). temperature is currently around 25'C, no signs of a lack of oxygen or anything. I changed one thing recently: at water-changes i started using Sera aquatan , but I find it hard to imagine why this would affect only male Ameca (and not Xenotoca San marcos in the same aquarium, and also not female Ameca).
I started using this product because of a reaction of Poecilia wingei to water changes. P wingei are in another aquarium (and are "difficult" since I obtained them - this is the Eckert-strain from the type-locality).
Any suggestions what to look for with Ameca?
Grigri posted: 13.05.2011
Hello Paul !
Could it be due to agressivity in reply tto the change of group structure ?
it could explain why only males are affected...
I some times have some kind of similar problem with my audax... often after fishing some of them !
Michael Koeck posted: 13.05.2011
Hi Paul,
many years ago, I read about similar problems with Molls, caused by a certain kind of fungus, I think, it had been Ichthyosporidium. As far as I can remember, the author mentioned that it grows in muscles and the appearance of the flesh is milky, not clear anymore. The mollies lost control, wabbled and spinned around and died. As far as I can remember, there had been no real help for infected fish. This is just an idea, no diagnosis, sorry, but maybe it helps you.
Mike
Illustrator posted: 13.05.2011
I don't think agression can be the problem, because the males are barely getting some colour in their tail - they are not really adult yet. Also, Ameca is not very agressive when there are several males together (= more than 2 or 3).
An infection sounds likely, but then, why would it affect only males? I could imagine that an infection was present before and is now triggered by the relatively warm weather (aquarium temperature also raised for a few degrees).
Michael Koeck posted: 14.05.2011
May be possible, also that it has been triggered by sexual activity of males (courthship)and therefore a stress-situation combined with the warm weather (oxygen-situation). However, just an idea, not more...
Mike
Illustrator posted: 29.05.2011
Maybe I figured it out: what if it is an infection that spreads by "cannibalism"? Every now and then a fish is missing a piece of fin. The few times I saw what happened, it was always a male Ameca biting a piece of fin of a juvenile or subadult. Naturally, infected juvenile fish are the first victims (and indeed quickly miss much of their tail fin).
Then the question how it got to my aquarium: I have obtained some Characodon lateralis, of which the male has consistently a too thick slime-layer in the dorsal fin. What if these carry the infection? One of the Characodon is a subadult male and indeed this one was missing pieces of it's tail fin some time ago (recovering now). So what if it is some kind of infection to which Characodon has a reasonable resistance, but Ameca has not? At this point it's a lot of speculation, of course.
And some bad news: it must be spreading in other ways as well, because by now also young female Ameca are affected.
Illustrator posted: 11.06.2011
I't has apparently quieted down. All males that were potentially sexually active (and territorial) died, as well as a few females and an unknown number of juveniles.
Remaining are more than enough half-grown females, some of which are pregnant, and a bunch of juveniles. I brought a male (of the same strain) back from a tank of feeder-fish, so that there is one (a bit retarded) adult male present and 2 juvenile males are now maturing. I expect no problems with maintaining the strain.
I culled a half-grown Characodon, which might have been the carrier. This, btw, is the only Goodeid which I have seen which had a shortened vertebral column like a "baloon-molly", a fish which I woud have culled before if I would have had more Characodon. I now regret not photographing this Characodon ...
mandrade posted: 18.06.2011
Hi Paul,
Sorry for this late participation, but work and other responsibilities had keep me absent.
Once I have faced a similar case with Skiffia multipunctata ( except for the males removal detail... in my case the coincidence it was a part of the group, including males and females together ).
It wasn't possible to determinate the causes.
The losses ended up with daily water changes ( around 10% tank volume ).
Please avoid tap water if possible and try to respect the same chemistry.
After the fatalities cessed the partial water changes were reduced to 4 times a week and I had no more mysterious deaths.
Good luck !
Best regards
Miguel Andrade
The story continues. For over
The story continues. For over a year the remaining fish were appearing healthy and reproducing well so I build up a nice group of the same strain. About 2 months ago some Ameca started to get the same symptoms and then one by one they started dying. Frequent water changes have not helped (3 times/week 1/3 or more of the water; nitrate and nitrite below testable limits). First juveniles died, then also adults of which males are apparently more sensitive than females. Reproduction stopped entirely. I now have 2 males left, of which the dominant one today developed "second stage" symptoms and the submissive one is has "first stage" symptoms. There are still some 8 females of which at least one is having "first stage" symptoms as well. I have no back-up in another aquarium this time. I intend to take care of the outwards healthy ones untill they get ill as well, to see how it ends. This is very frustrating.
Interesting, Xenotoca "San Marcos" and a single Skiffia "Sayula" are unaffected even though they are in the same aquarium.
Re-description of symptoms:
- first stage: a slight bending of the caudal peduncle. Almost unnoticable, mostly upwards, can also be slightly sidewards. This is practically indistinguishable from a very slight deformity. Fish behave normally, sometimes swim with very slightly squeezed fins. If I wouldn't look very very critically at them, I would not notice this stage at all. This can last up to several weeks.
- second stage: a sudden very dramatic worsening. With sudden I mean that in the morning a fish is in the first stage and in the afternoon, when I come home, it is hardly able to swim. Also stress like a water change can trigger the change from the first stage to the second stage. Basically the whole caudal peduncle is paralyzed and normal swimming is very much impared. Muscle tissue in the caudal peduncle turns opaque. The fish is inactive and hiding in places where you would expect a submissive fish to hide: between plants or close to the water surface. Fins are frequently widely spread, balance is largely kept with the pectoral fins. The fish reacts normally to food and also shows some agression towards other fish.
- third stage is basically a worsening of the second one: paralysis spready gradually forewards. Fins, especially the tail fin become damaged (unclear if because of actions from other fish or becaus of secondary bacterial infections, I suspect the latter). General health worsening, fish become pale and thin. This can last several days.
- final stage: death. But I tend to euthanise fish before this happens, it does not look like they have any chance of recovering.
How it continued: I gradually
How it continued: I gradually lost my Ameca and Characodon. This is frustrating, but I do not want to re-start untill I have some idea what was going on.
Maybe I figured it out: the tapwater here is coming from karstic springs. There were some changes and we switched to another spring. I was not too worried as "livebearers like hard water" and the overall water quality is good. For years I use natural river sand as substrate, however this is alkaline. Combined this gives a GH of well over 20'. I presume that this was gradually poisoning my Ameca, am I correct that they originate from much softer water? Xenotoca "San Marcos" continues to thrive in this extremely hard water.
How it continued: I gradually
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