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Cyathopharynx foai


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</STRONG></DIV><H1>Foai question</H1><DIV id=Qtextbox><P><STRONG>Author: fiona ls</STRONG><BR><BR>I have some young foai. They are all showing some black edging/tipping on the leading edge of the dorsal fin. Is this sex related? Are they all males? Or can females show this too?

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Further: there seems to be some pictures of a female showing black tipping

here

but it's difficult to be sure. Someone who keeps these would know for certain.

</P></DIV><H2>Replies »</H2><DIV id=Atextbox><P><STRONG>Author: Meiji BANKSTOWN</STRONG><BR><BR>hi fiona,

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mine sometimes, all of them have black edging on their dorsal fin. especially after a water change

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so far i can tell that i have 2 males, because

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(1) at a certain angles (in direct sunlight) 2 of my fish possesses alot more shiny blue colors than the rest

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(2) their dorsal fins are very different to the rest. both have black edging and also approx 2mm inside those black edging theres a darkish line or a change in gradient/texture from the actual clear(?) dorsal fins.

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(3) both have longer pelvic(?) fins than the rest, extending to the middle on the anal fin.

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HTH

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and also, can someone also help me:

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issit natural for furcifer/foai to produce mixture of opaque-whitish-clear poo? is this the case for your foai also Fiona?

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i think maybe its internal parasites? how can i overcome this problem

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TIA

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Meiji

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</P></DIV><DIV id=Atextbox><P><STRONG>Author: fiona ls</STRONG><BR><BR>What size are yours? Mine are maybe 7-8cm (larger ones) and maybe about 6-7cm (smaller ones, younger) including caudal fin. At this size, they all have clear dorsal fins apart from the black tipping, and none have pelvic fins that go past the anal fin leading edge. They stop about the anus. Although there are a couple of fin tips missing so they may be longer? Hard to tell. Not much longer I think. They also have a similar amount of forking on the tail, with fairly rounded tips. None of them have noticeably more colour in their bodies than the others, all at times seem to show a little (very small) flush of green/blue reflected colour depending on the light. Mostly they are just silver, with some darker greying markings at times.

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ATM they are doing brownish poo. I think I remember them doing ligher poos at times. Could it be diet related at all? Do the poos break off short or are they long and stringy?

</P></DIV><DIV id=Atextbox><P><STRONG>Author: chorrylan</STRONG><BR><BR>hi fiona,

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I've found it extremely hard to identify the sex of foai/furcifer until they decide to start performing and then it's kinda obvious. (though I've had "females" 12-13cm in size decide to start colouring up *ungrateful sods*)

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Having a collection of evenly sized juveniles and another set of babies is actually a worst case scenario as you run the risk of all the big ones deciding they should be males.

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My recommendation in your case would be to try and find an identifiably male karilani that's a tad larger than yours and add him to your colony.

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With an unamiously agreed dominant-male in the colony you should increase the probability that the existing fish will stick to the female side of the line.

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I think ben mentioned he had some spare young males when he reported his mothers-day-disaster.

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Cheers,

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Laurie

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</P></DIV><DIV id=Atextbox><P><STRONG>Author: fiona ls</STRONG><BR><BR>Oh, that's interesting. So they can change their sex? I kind of thought that it was like people: you were born one thing or another. If they can change their sex then that sounds like a good idea.

</P></DIV><DIV id=Atextbox><P><STRONG>Author: chorrylan</STRONG><BR><BR>hi,

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I don't think there's much evidence to support the idea that these particular species can change sex (eg like barramundi or west australian jewfish) but quite a bit of anecdotal evidence (and some real research though I haven't seen any on Cyathopharynx specifically) that they can and do delay the point of sex determination.

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For many fish species it appears that sex is not pre-determined or even determined in the egg or while babies but can occur months or even years into their lives.

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Try a relatively quick and easy experiment: grow up a 1x 4cm electric yellow and 4x 2cm elecric yellows. I've only tried this particular experiment three times (after seeing it happen quite a few times by accident) but in all three the larger fish ended up being a male even though it wasn't a dominant fish amongst it's original age-group. Conversely I never got more than one of the other 4 that looked like a male (I didn't keep them breeding size so they could have just been delaying).

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It'd be really interesting to see if this holds true across a decent sample population, across other species and over a longer period of time (I sold the yellows or merged them with my colony when they got to around 5-6cm).

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Even if it's just a silly superstition I'm convinced enough that I try to provide a couple of slightly bigger fish to take out the head-honcho posts rather than let the fry sort things out for themselves.

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There's some interesting reading here:

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http://www-personal.umich.edu/~roldfiel/re...chinterests.htm

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Cheers,

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Laurie

</P></DIV><DIV id=Atextbox><P><STRONG>Author: fiona ls</STRONG><BR><BR>Hm, that is interesting. I had a similar experience with Hongi. I had bought 6 about the same size, of which 2 seemed to be males and 4 females. I then bought 2 more females from Ben to add to the colony. These were larger. Ben and Andy had sorted Ben's Hongi by sex and were as sure as anyone could be that these were females.

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The two larger females ended up being males. Of the two smaller males one is a male and the other female. All the others (also in the smaller group) are female. This would support this theory.

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There was also a teeny one I got from Andy. It's grown up with all the bigger ones (once it got large enough to go in) and it seems to be a male. Which would not support the theory.

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Thanks for the article links. I tried to find some more info and had a look through some academic journal databases and came up with

this article

. It's a big one, in pdf format, but interesting. Give it time to download. I haven't read the whole thing! But I have read bits of it. And come across some words I don't understand, too. I have saved the file and put it up on my server so you can look if you want to read it (it was on a limited access database), if you haven't seen it before you will probably find it interesting.

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I am going to see if I can change the format of the article to something a bit smaller than the pdf so if you have trouble, I may be able to fix it. It was only available by pdf to me.

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I have made it into html. It's still quite a big file. And no pictures or navigation assistance like in the pdf. Still, if there is a problem for you with the pdf, you can access the html file

here

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</P></DIV><DIV id=Atextbox><P><STRONG>Author: saudukar</STRONG><BR><BR>My own opinion is that sex determination in young cichlids is purely wishful thinking by the part of the owner.

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They determine females to be females based purely on visable evidence. Any of these 'determined' females could be a underdeveloped or subdomainate male. Of course we all love to think that all smaller/uncoloured young are females. Its always the intention to have more females than males.

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Of course picking sexually active dominate male is bloody easy. But even fully sized adults can retard male colouration. It been proven in my sexually colour morphic species like Ps. lombardoi and Mel.johanni.

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To be said that Im sure its possible for one cichlid sex to start producing more opposite sex hormones but I highly doubt that in the many species of cichlids and types of breeding topology that this 'advantage' of changing sex hasnt been utilised more specifically by a species.

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More likely sex is determined during the fetual growth stages when the sexual organs are forming. And that females (ones that hold eggs but change colour later) that somehow 'change' into males are females that produce more male sexual hormones but do not have male reproductive organs.

</P></DIV><DIV id=Atextbox><P><STRONG>Author: chorrylan</STRONG><BR><BR>yep I'm happy to 'fess up to wishful thinking and just plain bein' superstitious but this issue is much more complex than that; plus it appears different species.

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eg in the article fiona posted they claim that only about 10% of fish species examined have sex chromosomes (and hence fit the classic sex is determined by your chromosomes model);

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There are rare but verifiable examples of protogynous and proteandrous fish species where at least some of the fish get to try out both genders in their lifetimes.

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Much more common (apparently) is simply delayed sex-determination, ie the period you define as "when the sexual organs are forming" simply takes much longer than we would consider possible in a human or mammalian context.

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So we have fish of "haven't decided yet but look like a juvenile/female" gender becoming sexually active males because the opportunity arises whereas it appears possible that the same fish might have become a sexually active female under the right circumstances.

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This is not quite the same thing as gender-changing but is in terms of the final outcome if you're "hoping" to push the probabilities one way or the other.

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The humble krib is a reasonably well researched example like this. There have been numerous experiments that show you can alter the gender balance by changing the Ph during their formative process (and not just as eggs but as fry). For memory the proportion of males increased as the Ph rose.....

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Cheers,

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Laurie

</P></DIV><DIV id=Atextbox><P><STRONG>Author: Fronty</STRONG><BR><BR>Sorry guys but after the worst day of fish keeping I have ever had, waking to my dead male furcifer x 3, I am not selling any of my coppers until I get a breeding colony up and going again.

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I will post on the board when I do have something for sale.

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Sorry guys

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As far as sexing them, yes Laurie is right. I tried it a few weeks ago and it worked. I put a proven male in the tank with my other coppers and one of the suspect fish is now looking like its going to be a male. But only time will tell.

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The foai and furcifer need about 2 years before you will see any real action and colour. Like a fronty they need time, space and a tank of their own.

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Good luck

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Also Fiona you have furcifer not foai.

I know it confusing. I get them mixed up all the time.

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Thanks

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Ben and Kristy

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</P></DIV><DIV id=Atextbox><P><STRONG>Author: fiona ls</STRONG><BR><BR>Thanks for that info, Ben. That basically answers my initial query, which was whether was I was seeing was a sign of sexual differentiation. It seems that it is not.

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Also, I can completely understand your decision not to part with any Coppers at this time.

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Where/how does one find out whether a Cyathopharynx is furcifer or foai? The Karilani Copper is listed as both in varying places.

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Regarding sex determination in fish, from reading the literature it becomes evident that it is much more complex than in, for example, mammals. In mammals it's a single chromosome, whereas it seems that in fish it may be polygenic, and that environment plays a significant part.

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I found another interesting article

here

(easier to read than the academic one). This shows, among other things, a link between size and sex in Midas cichlids. The link being, not that males grow faster, but that larger fish (by comparison with companions) become males. Very interesting. Reading that reminded me of a comment on the classifieds board, under a post wanting a male festae, that lots of people seem to have females and not males. That triggered a memory of reading that with the Midas experiment, fish kept on their own tended to become female. I wonder if that has any significance for keepers of any of the other large Americans. It would be interesting to hear some anecdotal evidence one way or another.

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And as Laurie mentioned, that article also outlines the relation in pelvicachromines between sex and pH with low pH producing more males and higher pH producing more females. It also mentions pH and Apistogramma, and the longer article also mentions temperature as a factor in the Apistos.

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Gosh there is a lot to it.

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I have learned a lot about sexual determination in fish after asking this "simple" question, and have much more to learn (I have to finish that enormous article I found among other things). Unless a study (or more) is done on the specific fish I keep it may remain surmisal - but knowing some of the pathways to sexual determination gives a hint of some strategies to follow.

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