Lake Malawi Species • Auratus & Gender Change

Discussion regarding only Lake Malawi species.

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Postby scrubjay » Fri Apr 16, 2010 2:38 pm

OK, understand I am not trying to pick a fight or anything here, but I want to go into this a little more. The reason is that part of my job is being a research librarian and doing review of scientific literature on topics related to fish ecology and biology. I have also edited scientific papers for people prior to their submittal to journals. I just want to explain why, although skepticism is a truly healthy outlook, especially in today's world, the results of scientific research published in academic journals is probably the last place you need to apply it. I am the biggest skeptic, so I should know! :D
"but yall are all acting like it is common knowledge that African Cichlids can change sex"
Nope, not exactly. The publication of this article will be seen as empirical evidence that sex change occurred in these particular subjects under these particular conditions. You can't necessarily extrapolate the results to any other species or conditions. But you can continue to investigate the subject and see if this is common or not.
"Read by a couple of academic folk before publication (freinds maybe) who have never vissited or checked the experiments (and for sure did not check the species name as being valid) would be my guess."
They reported the species name accurately. In binomial nomenclature, "cf." is used when identification has not been absolutely confirmed. The reason they used it is because the taxonomy of Metriaclima and many other Malawi cichlids has not been entirely worked out, and speciation continues. See:
http://www.pnas.org/content/96/9/5107.full.pdf+html

You do not get to choose who reviews your work prior to publication in an academic journal.
"Reviewers are typically anonymous and independent, to help foster unvarnished criticism, and to discourage cronyism in funding and publication decisions. Since reviewers are normally selected from experts in the fields discussed in the article, the process of peer review is considered critical to establishing a reliable body of research and knowledge. Scholars reading the published articles can only be expert in a limited area; they rely, to some degree, on the peer-review process to provide reliable and credible research that they can build upon for subsequent or related research. As a result, significant scandal ensues when an author is found to have falsified the research included in an article, as many other scholars, and the field of study itself, may have relied upon the original research."

In other words, to report something inaccurately, or to bias the experiment or results, would not benefit the authors in any way. Quite the contrary--it would ruin their reputations.

"Why was this not picked up if it had a good peer review before apearing?"

Probably because hobbyists are not as likely to be members of associations such as the American Society of Ichthyologists and Herpetologists? http://www.asihcopeiaonline.org/ There are thousands of academic journals published every month. http://journalseek.net/bio.htm If you want to keep up on cichlid research, you could bookmark all those where such research is published and monitor the tables of contents each month. I monitor 50 journals related to salmon biology, river ecology, fluvial geomorphology, etc. as part of my job, but I pay for a service to have them emailed to me.

If you are truly interested in academic research on cichlids, you can do searches using GoogleScholar and find everything published on the subject that is in electronic form. The problem is that you need paid access to view the full text of many papers and subscriptions to scientific journals can cost hundreds of dollars each; therefore, it is best to have access to a university library to view the actual papers.
For example, a search of "cichlids sex change" brings up quite a lot of papers on the subject, that similar results were found decades ago, and that maybe this is nothing to be surprised at:
http://www.springerlink.com/content/q1g1q18w6564m13t/
http://www.springerlink.com/content/q63777pq170k3518/fulltext.pdf?page=1
http://filer.case.edu/rgo/OldfieldFAF2005.pdf
http://www.jstor.org/pss/2830890
Finally, although I knew that some fish could change sex, I did not know that cichlids did, and I did not know that it could result from behavioral interactions. But now that I see the research that has been done, it's enough to convince me that it can happen under certain circumstances.
"Sexual differentiation in teleost [bony] fishes is characteristically labile. The most dramatic form of sexual lability is postmaturational sex change, which is common among teleosts although rare or absent in other vertebrate taxa. In many cases this process is regulated by social cues, particularly dominance interactions."
http://www.pnas.org/content/90/22/10673.full.pdf+html
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Postby fox » Fri Apr 16, 2010 3:09 pm

scrubjay wrote: >snip< although skepticism is a truly healthy outlook, especially in today's world, the results of scientific research published in academic journals is probably the last place you need to apply it. >snip<


Unless of coarse it has to do with GW and data is conviently omitted to get the results wanted. :roll: :oops:

All research needs to be scrutinized and put to the test or we might just be fed someones view in a conviently accepted report. 'just sayin
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Postby scrubjay » Fri Apr 16, 2010 4:25 pm

Oh really? Do you know the results of that "scandal"? Obviously not. Because it was politically driven sensationalism and had nothing to do with the research conducted. The results of independent investigation of the "scandal" came out this week, as a matter of fact, the scientists were exonerated. They are not guilty of your charge.
http://www.peterboroughtoday.co.uk/news/national/clean_bill_of_health_for_climate_centre_1_505641
http://news.bbc.co.uk/2/hi/science/nature/8618024.stm
http://www.uea.ac.uk/mac/comm/media/press/CRUstatements/Report+of+the+Science+Assessment+Panel
http://www.timesonline.co.uk/tol/news/environment/article7097234.ece
"The report of the independent Science Assessment Panel was published on 14 April 2010 and concluded that the panel had seen "no evidence of any deliberate scientific malpractice in any of the work of the Climatic Research Unit." It found that the CRU's work had been "carried out with integrity" and had used "fair and satisfactory" methods. The CRU was found to be "objective and dispassionate in their view of the data and their results, and there was no hint of tailoring results to a particular agenda." Instead, "their sole aim was to establish as robust a record of temperatures in recent centuries as possible.""
Speaking at a press conference to announce the report, the panel's chair, Lord Oxburgh, stated that his team had found "absolutely no evidence of any impropriety whatsoever" and that "whatever was said in the emails, the basic science seems to have been done fairly and properly." He said that many of the criticisms and allegations of scientific misconduct had been made by people "who do not like the implications of some of the conclusions" reached by the CRU's scientists.
[quote]
"...the panel reserved its strongest criticism for the climate sceptics who had accused the unit of manipulating its findings. It said the attacks on the unit’s work had been “selective and uncharitableâ€Â
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Postby fox » Fri Apr 16, 2010 4:38 pm

Believe whatever agenda floats yer boat. Makes no never mind to me.

Someone tells me the world is flat I question it, you wanna believs it fine by me.
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Postby 24Tropheus » Fri Apr 16, 2010 4:38 pm

I can not find a reference elsewhere To Metriaclima livingstoni.
I find Pseudotropheus livingstonii and Maylandia livingstonii but no Metriaclima.
I dunno did the name lose an i and get moved again when I was distracted?
cf. means have no reason not to believe it is not this species or a similar one, as described.
If Metriclima livingstoni has not been described it is kind of meaningless.
We the readers, have no idea what species they are talking about.
Dunno but any Ichthyologist should have spotted this?
Kind of makes me warry about giving credence to anything else in there has been reviewed and tested when the title or titel :lol: has such a glaring error.

All the best James
Tanks 180, empty revamping 100,65,60g Tropheus/tang communities 75g revamping. 29gx3 shelly communities, 29g Trigs breeding. 20gx2 shelly tanks. BCA member 207. Try it you might like it.
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Postby scrubjay » Fri Apr 16, 2010 6:06 pm

No, They are not wrong and the title has no error. The hobby doesn't generally keep up with changes in nomenclature, and fish shops tend to use the names people have become used to. You are sort of missing the point by focusing on trivia that don't change the conclusions of the research.

The nomenclature of these cichlids has not been worked out, meaning that the scientific names have not been settled on. They have been revised more than once. I believe all were once grouped in the genus Pseudotropheus. Although Maylandia was proposed and used for this genus, there is some support for using Metriaclima and I believe this is the currently accepted name for the genus. They all refer to the same species. Common and scientific names of species get changed all the time and DNA research will continue to ensure that this will be the case. The complexity associated with determining species in Lake Malawi stems from the fact that more than 800 species seem to have evolved from possibly one or very few ancestral species in only 2 million years (this is very fast in geological time). And they are still evolving and speciating. Evolution hasn't stopped, and the whole idea of species in such an environment is a difficult subject.
https://www.cichlid-forum.com/articles/m ... landia.php

The subject of their evolution and taxonomy is well-represented in the literature.
http://www.jstor.org/pss/4065053
http://www.repository.naturalis.nl/document/148949
http://www.springerlink.com/content/95505615362m72h2/
http://pinnacle.allenpress.com/doi/abs/10.1643/0045-8511%282002%29002%5B0146:DOANSI%5D2.0.CO%3B2
http://planet.uwc.ac.za/nisl/Biodiversity/pdf/Fish%20and%20Fisheries%202002%20species%20concepts%20individuation%20Mayden.pdf
http://www.aqualog.de/news/web74/74-18-19e.pdf
http://www.springerlink.com/content/w0g1117651v871r0/
http://www.pnas.org/content/96/18/10230.abstract
http://www.ingentaconnect.com/content/bsc/mecol/2001/00000010/00000003/art00023
http://nature.umesci.maine.edu/pubs/ME2003.PDF

If you go to Chapter 14 in this book, you can read some of the chapter on cichlid speciation.
http://books.google.com/books?hl=en&lr=&id=7GKkbJ4yOKAC&oi=fnd&pg=PA213&ots=CUbU_djb7b&sig=PMZFw2Yw3pA1f0mD4Vlva6cNdCQ#v=onepage&q&f=false
http://mbe.oxfordjournals.org/cgi/reprint/10/5/1060

If you really want to understand all of this fun nerdy stuff, I suggest this book
http://www.amazon.com/Cichlid-Fishes-Behaviour-evolution-Fisheries/dp/0412322005
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Postby 24Tropheus » Fri Apr 16, 2010 8:14 pm

The conclusion of that research (I think) is that one species of Mbuna can change sex from female to male based on a couple of individuals in a single trial in cirtain circumstances. We have no idea how common this is or wheather it can be inferred that it can happen in other Mbuna. I would like to know which Mbuna species they observed this in. My guess would be the species described as Pseudotropheus livingstonii (Boulenger, 1899) but I can not be sure because of this name problem. It could be Metriaclima lanisticola (Burgess, 1976) (assuming that that is not the same species) or maybe something else.

Thanks for the links, keep me happy for hours. :wink:

I notice in the references Hale, E.A., J.R. Stauffer, Jr., and M.D. Mahaffy. 1998. Exceptions to color being a sexually dimorphic character in Melanochromis auratus (Teleostei: Cichlidae). Ichthyological Exploration of Freshwaters 9: 263-266.. Perhaps that might be worth chasing up to give a good answer to the original post?
http://malawicichlids.com/_popup_abs_hsm98.htm
I can only get the abstract perhaps you can show us the whole study?
I suspect that there is no firm answer yet to the original post but it might be nice to check.

All the best James
Tanks 180, empty revamping 100,65,60g Tropheus/tang communities 75g revamping. 29gx3 shelly communities, 29g Trigs breeding. 20gx2 shelly tanks. BCA member 207. Try it you might like it.
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Postby Number6 » Fri Apr 16, 2010 8:42 pm

24Tropheus wrote:The conclusion of that research (I think) is that one species of Mbuna can change sex from female to male based on a couple of individuals in a single trial in cirtain circumstances. We have no idea how common this is or wheather it can be inferred that it can happen in other Mbuna.

sort of splitting hairs me thinks... sure, you couldn't definitively say that all mbuna have this capability but you have to remember the hypothesis prior to the study and then think about the fact that the species selected turned out to have the trait exactly as expected!

Probability says that there are other mbuna that will share this capability. If I were a betting man, I know what color I'd put my money on! :D
My WC cichlids are gonna be caught on rod n reel!
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Postby DJRansome » Fri Apr 16, 2010 9:01 pm

Metriaclima livingstoni is listed in Konings 4th Edition, was Metriaclima lanisticola.

GaFishMan1181, I was a skeptic. And I thought many of the knowledgeable members here were too. But I recognized the name J.Stauffer so I asked around. What a cool thread. I also learned a lot from ScrubJay about peer reviewed papers, etc.

I imagine I will never see this in a tank of mine. And I would not be totally surprised to see a paper in the future with a differing point of view. But at least now I know better than to say it's impossible.
Last edited by DJRansome on Fri Apr 16, 2010 9:33 pm, edited 1 time in total.
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Postby 24Tropheus » Fri Apr 16, 2010 9:24 pm

Number6 wrote:
24Tropheus wrote:The conclusion of that research (I think) is that one species of Mbuna can change sex from female to male based on a couple of individuals in a single trial in cirtain circumstances. We have no idea how common this is or wheather it can be inferred that it can happen in other Mbuna.

sort of splitting hairs me thinks... sure, you couldn't definitively say that all mbuna have this capability but you have to remember the hypothesis prior to the study and then think about the fact that the species selected turned out to have the trait exactly as expected!

Probability says that there are other mbuna that will share this capability. If I were a betting man, I know what color I'd put my money on! :D


I would agree with that. Its sure going to be interesting (as the gates are open) how many Mbuna this might be found in. I see quite a lot of anacdotal evidence from hobbiests, would it not be nice for many of em to be proved right after being scoffed at. :wink:
So sex change for sure in a species similar or the same as lanisticola, we think (thanks for that) and who knows what other Mbuna. 8)

All the best James

Arg one more thought. lanisticola is quite unusual in being a Mbuna shelldweller. I take it this does not make it more likely to be different/unusual in other respects?

I can kind of see a special advantage in a species that meets up in shells far apart to have the ability to change sex (two random fish far more likely to be able to breed), more than say a species that lives in large multi sex groups. Or a fish that lives in widely separated single male dominated hareems being able to replace a lost male from within.
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Postby scrubjay » Sat Apr 17, 2010 12:03 am

The motherlode bibliography appears to reside here:
http://www.malawicichlids.com/mw14001.htm
with a list of journals that have open (free access):
http://www.malawicichlids.com/mw14500.htm

I notice in the references Hale, E.A., J.R. Stauffer, Jr., and M.D. Mahaffy. 1998. Exceptions to color being a sexually dimorphic character in Melanochromis auratus (Teleostei: Cichlidae). Ichthyological Exploration of Freshwaters 9: 263-266.. Perhaps that might be worth chasing up to give a good answer to the original post?

I'm not familiar with the journal and can't find a free electronic version, unfortunately. If someone has access to a university library in Europe, they might be able to get a copy. Some journals haven't scanned all the older articles though, and 1998 may be too early.
http://www.pfeil-verlag.de/04biol/e9902d9.html

You know, after scanning the methods used in the Stauffer paper, it wouldn't be all that hard to reproduce their experiment at home with other species. I suggest somebody try it! Not all research has to be published in a journal; there are other outlets for amateur research, like this site!
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Postby LongIslandCichlid » Mon Apr 19, 2010 10:34 pm

Yes auratus can change their sex. yes Gafishman i was just like you I would of never believed anyone but it happened to me (I will post photos) I had one large Auratus male and 3 females all 3 females held eggs and raised fry about a year ago the male died and 2 of the females changed teams within a month the colors changed and they started displaying “maleâ€Â
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Postby LongIslandCichlid » Mon Apr 19, 2010 11:15 pm

Image
Holding Female

Image
dominant male was a female at one time
Image
subdominant male was also a female at one time
Image
150 gal tank
Image
6 week old Auratus
Image
close up of a 6 week old Auratus

Image
not an Auratus but it is a mom and her.....
Image
fry
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Postby scrubjay » Tue Apr 20, 2010 12:49 am

[quote="LongIslandCichlid"]Yes auratus can change their sex. yes Gafishman i was just like you I would of never believed anyone but it happened to me (I will post photos) I had one large Auratus male and 3 females all 3 females held eggs and raised fry about a year ago the male died and 2 of the females changed teams within a month the colors changed and they started displaying “maleâ€Â
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Postby Kanorin » Tue Apr 20, 2010 11:04 am

Very interesting thread - I also stand corrected that this cannot happen. And clearly, this is not a phenomenon isolated to just a single species. Go Science!

I had a tank with only 3 female melanochromis cyaneorhabdos for about 4-5 months (after I got rid of the male for being too aggressive). Pretty soon after getting rid of the male, one of the females definitely took over as the dominant member of the species. She never spawned with the other females, but I wonder if she was going through a sex-change and if I would have kept them around longer if she would have :-?

I wonder if this phenomenon has any developmental limits. In other words, can a three year old female change sex with the same facility that a 6 month old female can?

Also note that they observed male : female ratios in their F1 broods of approximately five to ten females per every male. Those high female to male ratios are not common in most tank-raised african cichlid broods. Perhaps it suggests that the Met. Livingstoni species has more hormonal cross-talk (or whatever factor is mediating these gender changes) than the average cichlid.
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