E.gilberti breeding problems
Posted 19 November 2013 - 03:52 PM
Those are two very good suggestions.
Posted 19 November 2013 - 04:25 PM
If gilberti and okefenokee can and will interbreed freely as you speculate, then how did both species come to occupy and persist in those areas of the middle Suwanee River basin where their ranges are adjacent (and maybe overlapping a bit)?
I agree it's unlikely that Knut ended up with females of one species and males of another in his original breeders, but it's possible. A collector may have made multiple trips to a variety of sites (some in okefenokee range, some in gilberti range) and combined fish from different sites. Or the exporter might have combined fish from different collectors. I also agree Elassoma probably travel less than most fish (from their place of birth), but obviously they DO disperse or you wouldn't find one species in multiple river basins.
... there's no biological reason why the offspring between gilberti and okefenokee would be infertile that I can think of. Read about serval-cat hybrids and wolf-dog hybrids. They have different gestation time periods, different number of chromosome, different number of teeth, and they're still fertile or, if the male's infertile, the females are, and the way the lifespan of this fish is, they would breed with the purebred males. There's no reason why okefenokee gilberti hybrids wouldn't be fertile. It's like the same fish, except a different range and different preopercular pores count. Same egg hatch time period, same egg size, same larval size, same internal organs, same everything except range and preopercular pores. They'd hybridize grandly.
Now that Knut has posted his questions here and we've all debated it, his fish will probably breed successfully.
That's usually all it takes |;>)
Posted 19 November 2013 - 04:42 PM
If gilberti and okefenokee can and will interbreed freely as you speculate, then how did both species come to occupy and persist in those areas of the middle Suwanee River basin where their ranges are adjacent (and maybe overlapping a bit)?.
This is very important. If they did breed freely, and produce 100% fertile offspring, then we should not see them differentiated in overlapping range within the same drainage. Good way to make this easy to understand. Wonder what separated them enough in the first place to become different species? Different drainages originally, and eventual stream capture?
Posted 19 November 2013 - 05:01 PM
Just emphasizing this. The questions got a little bit buried.
- Have you tried putting two pairs into an empty tank for a month and pulling them out?
- Have you tried siphoning the bottom of your main tank and raising the siphon water in a fry tank?
Posted 19 November 2013 - 05:15 PM
"No, I feed self caugh live food (like Cyclops, Daphnia, and mosquitolarvae) every day. I also feed self breed Protozoa to the larvae. I use rainwater (with a bit of tap water in it) for all my Elassoma to breed for years. I also breed several other Elassoma all the time. And I had never any problems with them. Right now I breed evergladei, zonatum and okees. I´m really a fish freak for over 25 years now (with more than 30 aquariums in two rooms), so I know how to breed. I tried everything, Water changes with fresh and cold water. Different pH. Different diet. Different aquariums and combinations! Nothing worked. But what sounds compelling to me is that the parents where maybe gilberti males and okee females... I got them as wild caught fish from the USA. From a comercial import!
Posted 19 November 2013 - 05:34 PM
Example if they cannot hybridize:
A clump of grass has 0 elassoma. One breeding pair of gilberti finds their way in and breeds up to 2,000. Let's say the capacity of the grass is 50,000 animals. Next year, one pair of okefenokee finds their way in. If there were no hybrids, that clump of grass would soon have a mixed population of okefenokee and gilberti, let's say 10,000 total animals. The surveyors come by and they sample 200 fish. What would they find? They would find 170 gilberti, 30 okefenokee, zero hybrids. Or maybe there would be a few sterile hybrids, but there would be two distinct populations of both species in that same clump of grass. Okfenokee and gilberti don't have a competitive edge over one another, so you'd get both species present.
Alternative: They can hybridize
A clump of grass has 0 elassoma. One breeding pair of gilberti finds their way in and breeds up to 2,000. Let's say the capacity of the grass is 50,000 animals. Next year, one pair of okefenokee finds their way in. This pair breeds in, and their genes are quickly engulfed and overwhelmed by the majority. It's like if you have one brown skinned grandparent, like I do. I look relatively white skinned because three out of four of my grandparents had light skin. So say breeding happens and you get 10,000 total animals. The surveyors come by and they sample 200 fish. What would they find? They would find 190+ gilberti, a few mixed breeds, and zero to hardly any pureblood okfenokees.
What does Table 5 say? http://biology.unm.e...et al. 2009.pdf
The second situation. There are no clumps of plant with both okefenokee and gilberti. The sampling result in each location is an overwhelming number of one pure species and a few mixed pore individuals. Therefore I think they interbreed.
I bet they don't travel much.
Posted 19 November 2013 - 06:03 PM
Posted 19 November 2013 - 06:10 PM
It's good to talk these things over with other breeders. It really, really helps. Step one is asking if the adults are breeding (they are, I see them colored up in the first post). Step two is asking if the fry are surviving to adult hood. It's in no way an insult, it's just the dichotomous key of problem solving. If he/she wants help, that means we have to ask silly questions in order to rule out obvious things. Silly question being: are the adults in the same tank as the fry. You gotta ask it in order to rule it out and move on to other things.
The OP sounds like an expert breeder, probably not making rookie mistakes....Do you really think this fellow has been breeding Elassoma for years, and has not worked out simple problems. It is common knowledge not to let your adults eat all of the fry....
Posted 19 November 2013 - 06:18 PM
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