A Lazarus killie

[GaryE]

In 2023, I caught a fish in a flow through roadside pothole in Gabon. The tiny habitat was fed by spray from a small waterfall, full of leaves, and we took enough fish out of there to divide them 4 ways. The place was called Les Cascades Thad, so Aphyosemion escherichi Cascades Tchad was the name we put on it.

A while ago, I thought the line was done. Every single young fish I raised turned out female. At one point I had 35 of them. My old male, a fair adult when I caught him, died recently.
My fishing companions had also lost them. So that was that.

Or was it? Clearly not, if I'm telling this story.

In a 20 gallon jungle tank I'd left them in in a last desperate try, I spotted 5 fry, long after I'd stopped feeding the tank. I fixed that quickly, and today I can report I have 2 males and 3 females.

I have no idea what gave me that sex ratio after two years of only females, but whatever it was, I'll take it.

Never give up,...

 

[gwand]

I will take that to heart and keep trying. From a July 3 a. cacatuoides hatch, I had one male and 20 females. I increased the tank temperature and had a second hatch on September 19. I have about 30 juveniles but it’s too early to sex them. My sailfin Mollies gave me 31 females and no males. My yellow tiger endlers gave me 12 females and no males. The girls always did like me.

 

[Magnum Man]

makes me wonder if that is man at work, on domestic raised fish, or in @GaryE 's case mother nature, at work... assuming one male can service many females on killies, it probably works better for them in the wild... only frustrating to us with literal "puddles", with no room for a "working population"

cichlids bred in captivity may get exposed to hormones to help with breeding "on the farm" which could result in skewed sex populations, in future generations???

I find it strange in evolution, that a few degrees temp change effects the ratio of males vrs females ( I don't see any advantage for that in nature )

 

[GaryE]

I can see how the ratios get weird.
First, where we get the killies in question, the air temperature is consistent, equatorial, 26 degrees. The water should follow, at 22 based on data from a lot of collections at various times of year. We got a good ratio in every killie we collected in the wild.
Often, more males get caught because they display, and therefore stay in the open more.
We caught good ratios on small numbers of Aphyosemion joergenscheeli, cameronense, citrineipinnis, escherichi, and primigenium. The same for Epiplatys singa, ansorgii and huberi. We must have gotten 7 or 8 Platopocheilus species (I'd have to check notes) , several undescribed, but all even in ratios.
So it's something we're doing in our tanks. What is the question breeders have worked on for 50 years, with no definitive answers. Diet? Water hardness? pH? Flow? Luck? An unappeased stream deity?
All but the latter has been tested in various ways.
With West African Cichlids, some reasonable experiments have pointed to temperature being important.
We also have another captive issue - in our glass boxes, juveniles don't disperse. They can clearly sex each other before we know what we have, and in many Cichlid species, an alpha can kill subordinate males and females. Sometimes, the reduction of the brood as they age may not be random. In the wild, there would be lots of room for them to get out of each others' way. There are no corners or walls.

I talked myself into speculating with Aphyosemion zygaima about 20 years ago. At a higher hardness and pH. the first collection of them in 1989 got a high number of males to females. They also recorded a higher pH than I'd expect. It went with my observation of the lower the water hardness, the more females I'd get. I still use that trick as I still have the fish.

I think now, since the fish was found again in even ratios, that my rainy season/dry season (evaporation increasing hardness and pH) speculation was wrong. I don't think it's natural. I think I looked at nature to try to explain problems in nurture. I think with that one species, since I've done informal experiments with controls while keeping them since 1992 hardness is the key. But it isn't likely key in nature - it's a random mutation effect. Things don't happen for a reason.

As for farms using hormones, they do in many cases. Male dwarf cichlids sell better, and sell at a high enough price the extra cost of the hormones is worth it. But I suspect they do it every generation to every brood.

That old nugget about fish being fine in any water is based on ignorance. I don't think you'll get many breeders who've worked with many types of fish who won't shake their heads when someone repeats that. And it's probably at the heart of our problems.

 

[anewbie]

I will take that to heart and keep trying. From a July 3 a. cacatuoides hatch, I had one male and 20 females. I increased the tank temperature and had a second hatch on September 19. I have about 30 juveniles but it’s too early to sex them. My sailfin Mollies gave me 31 females and no males. My yellow tiger endlers gave me 12 females and no males. The girls always did like me.

Don't know anything about killi but the problem with the cockatoo was human error with the temp too cold as there is a well understood relationship between temp and male/female ratio. I know this was discussed in another thread but the two situations might not be equivalent after all @GaryE's saving grace is the determination of sex of his species of killi is not well known at this time by him

 

[GaryE]

I think the issue of not giving up is what matters. If you get all one sex, maintain the breeding set up. Try another spawn. Then another. If it takes 20, then 20 it is.
But do as I say and not as I do - keep exact records of temps, hardness and pH. And do it by species, not by Genus.
I'm bad at record keeping.
Uwe Rohmer's old study said 26.5c gave 50/50 in Pelvicachromis dwarfs from West Africa. Immediately, Cichlid breeders started saying was also true for South American species, and maybe it is. I stopped breeding Apistos around then, so I wasn't able to see for myself.Show me a study of sex ratios in Aphyosemion escherichi and I'll be impressed. The fish isn't rare in its region but it has never had much of a toehold in the hobby.

I don't understand what you mean by 'saving grace'.

 

[anewbie]

I think the issue of not giving up is what matters. If you get all one sex, maintain the breeding set up. Try another spawn. Then another. If it takes 20, then 20 it is.
But do as I say and not as I do - keep exact records of temps, hardness and pH. And do it by species, not by Genus.
I'm bad at record keeping.
Uwe Rohmer's old study said 26.5c gave 50/50 in Pelvicachromis dwarfs from West Africa. Immediately, Cichlid breeders started saying was also true for South American species, and maybe it is. I stopped breeding Apistos around then, so I wasn't able to see for myself.Show me a study of sex ratios in Aphyosemion escherichi and I'll be impressed. The fish isn't rare in its region but it has never had much of a toehold in the hobby.

I don't understand what you mean by 'saving grace'.

While possible it is unlikely it was random chance you got all females. You just do't know the condition that triggers the sex for killi (something worth exploring or researching). As for cockatoo; they were a studied species and sex was determine to be temperature related - someone who collects them also noted that usually the dominant female is in a more favorable position ot produce males while less dominant females end up lower where it is cooler and produce more females (in the wild). I forget the exact period but it is within a few weeks after they hatch I think that sex is determined. Also the rules are not uniformed for all species (which make sense since some species are found in cooler regions).

As i said i know nothing about killi and it is just as likely water chemistry or the alignment of the moon as temperature that determine sex but [repeating myself] raw chance is highly unlikely if you got over 20 females without a male.

 

[gwand]

There are fewer fry than there are eggs, and there are fewer juveniles than there are fry (at least in my tanks). Is it possible males are more likely to die as fry compared to females? I don’t support my fry with infusoria. They live off the tank’s bounty until they are large enough to eat BBS.

 

[anewbie]

There are fewer fry than there are eggs, and there are fewer juveniles than there are fry (at least in my tanks). Is it possible males are more likely to die as fry compared to females? I don’t support my fry with infusoria. They live off the tank’s bounty until they are large enough to eat BBS.

Unlikely; also the frys are able to eat bbs as soon as their egg sacks are gone (usually 24 hours or so after they are free swimming). There is no reason for a 'gap' between 'live off of the tank bounty' and large enough to eat bbs. In fact those first few days are the most critical to supply food (IF you want a high yield). Of course since they can lay more than 50+ eggs perhaps you don't want a high yield.

Having said that my nijjensi frys made it just fine in a mature aquarium without bbs so there is that aspect.