[bguile]

I would like to add several Royal Gramma's to my new 90g tank. Anyone know how to tell the difference between male and female? I'm thinking that my 90g with all the places I have for hiding in my LR might be big enough for 2 males in case I picked up another one that wasn't female. Any thoughts on this? Is it hit or miss?

[Ninong]

Originally Posted by bguile

I would like to add several Royal Gramma's to my new 90g tank. Anyone know how to tell the difference between male and female?

According to Scott Michael, the only difference between the sexes is size. On average, males are larger than females and attain a greater length.

I'm thinking that my 90g with all the places I have for hiding in my LR might be big enough for 2 males in case I picked up another one that wasn't female. Any thoughts on this? Is it hit or miss?

According to the same source, the minimum size tank to house two males is larger than 1,000 sq. in. surface area. A standard glass 90-gal tank has approximately 800 sq. in. without subtracting for corner overflows.

P.S. -- Robert Fenner has a write-up on them on his website: http://www.wetwebmedia.com/grammas.htm

[bguile]

Thanks Ninong

[Ninong]

If you intend trying to keep more than one in a 90-gal tank, you should add them (2 or 3) all at once and there should be only one "large" individual. What you are hoping for is one male with one or two females. This is tricky because Gramma loreto is gonochoristic. It would be so much easier if it were hermaphroditic, but it's not.

[bguile]

I'm sorry...what's gonochoristic mean? Merriam-Webster didn't seem to know either so I don't feel too bad. I'm assuming you mean they are born male or female like us and don't exactly change sexes like clownfish do.

[Ninong]

Originally Posted by bguile

I'm sorry...what's gonochoristic mean? Merriam-Webster didn't seem to know either so I don't feel too bad. I'm assuming you mean they are born male or female like us and don't exactly change sexes like clownfish do.

Enter "gonochoristic" in your search engine: http://search.msn.com/results.aspx?F...=gonochoristic

[saltjunkie]

new words everyday, now if i can just use it in a sentence......

[Minh Nguyen]

I pasted from my other post:

Royal Grammas are hermaphrodites. The dominant member of the group will change sex to male while the rest stay as female. This change occurred very quickly. It is possible that it occurred in 1 to 2 weeks, maybe even quicker. Male Royal Grammas will kill each other (even in my 450 g aquarium full of rock).
Initially males and females RG appear identical. After sex change for several months, to an observant aquarist, the male RG have longer pelvic fins then female. My male RG have pelvic fin overlap the anal fin about 2 mm while female’s pelvic fins just reach the anal fins. You should not try to select male and female RG from their appearances.
The best way to obtain a group of RG is to get small ones that are keeping in-group at LFS. I guess when the LFS have two male RG together, on end up dead so they often keep RG one to a tank. I would avoid these unless you got to them one or two days after they arrive. Knowledgeable (or overcrowded) LFS often keep them in-group. I would get 3-5 smallest RG in this group and buy them. You would get a beautiful harem of RG in your tank that ready to breed in a few months.

[Ninong]

Minh,

Gramma loreto was widely believed to be a protogynous hermaphrodite based on observations such as your own about it's mating behavior but it is now believed to be gonochoristic.

Several hobby authors are still calling it a protogynous hermaphrodite but I believe that view is outdated. They are simply copying each other's earlier works, as usual.



P.S. -- If you google "gramma loreto gonochoristic" you will get several recent scientific and trade publications that list it as gonochoristic.

[Minh Nguyen]

Ninong,
I have the privilege to observed my harem of RG for several years and also observed the sex change and killing of my older male as he reach his old age. Therefore, I know what Scott wrote about RG sex is wrong. Everything else was right on.
Minh

We should merge the two RG thread together.

[Minh Nguyen]

BTW, I researched about RG several years before and did not find much reliable information. What I wrote about RG was strictly from my own observation of my Harem.
Minh

[Ninong]

Minh,

This is what we know so far based on a study of 167 Gramma loreto specimens by Kazue Asoh and Douglas Y. Shapiro that was published in February 1997 in Copeia, the journal of the American Society of Ichthyologists:

According to sex allocation theory, protogynous species ought to form social systems in which a relatively small number of males mate with a relatively large number of females. Because the fairy basslet, Gramma loreto, mates in this predicted manner, they examined its mode of sexuality, looking for evidence of protogyny, in 167 specimens ranging in size from small juveniles through adults.

All gonads initially developed previtellogenic oocytes and a precursor of the sperm ducts. In future males, the oocytes degenerated; the ducts proliferated, anastomosed, and became available for sperm transport; and spermatogenic tissue appeared.

In future females, an ovarian lumen was formed, the precursor sperm ducts degenerated, and oocytes continued to grow. No histological features indicative of protogyny were found.

In an experimental attempt to induce sex reversal, males were removed from social groups transferred from natural populations into the laboratory. Five months after male removal, no female contained any histological evidence of sex change.

All of that was taken from the abstract. I don't have access to the journal:
Bisexual Juvenile Gonad and Gonochorism in the Fairy Basslet, Gramma loreto
Kazue Asoh, Douglas Y. Shapiro
Copeia, Vol. 1997, No. 1 (Feb. 18, 1997) , pp. 22-31

Your personal observations appear to indicate that a mature female managed to regrow male gonads that had degenerated years earlier. As you can see from the experiment cited above, they found no evidence of any histological change after five months.

My own experience with Cirrhilabrus scottorum (Scott's Fairy Wrasse) is that a mature female will begin the sex change process within two or three weeks after removal of the dominant male, which is typical of protogyny.

If it is any comfort, I observed what I believe to be pair bonding between two terminal phase male C. scottorum in my tank -- after an initial period of hostility that lasted for 10 months -- and yet that is supposed to be impossible. I did manage to find one citation based on anecdotal observation of sex reversal in this genus in an aquarium setting. So perhaps it is possible that strange things sometimes happen in the unnatural confines of a small environment that would not happen naturally?

[Minh Nguyen]

I think we need to exam the study in full. I think that you would agree that reefers like us able to keep a reef tank much better than the majority of Scientists. I think we, as avid reefers, are able to keep them in a much more natural environment. I cannot comments on the finding of the study. I can comment on my observation. I can defiantly see the dimorphism of male and female RG. The most easily observed difference is the length of the pelvic fins. Objectively, mature males have elongated pelvic fins in comparison to the females. Subjectively, the colors of males are slightly more colorful, and males are bigger.
In my tank, a 450 g reef, I had a harem of RG with one male and four females. They breed on a regular basis. All 4 females take turn laying eggs. The male entice the females to his den. He would guard the eggs until they hatch about 10-12 days later. The eggs hatched early at night about 1-2 hrs after the light turn off for the day.
After about 18 months or so in my tank, the male got older and start to get weak. He lost weight. One day I found him fighting and was chased by one of the 'female'. In the battle over the next week or so, he lost one eye and died a few days later.
After several months, the group begins to breed again with the new male enticing the remaining three females and guard the eggs. The fry still hatches in early evening. The breeding activity goes on all year long instead of seasonal. My fish are very well fed, and the condition of my tank is stable year round with very little temperature variation.
The time frames of all these events maybe slightly off because I did not keep written notes. However, these are my true observation. There is no possibility of error in my observation of my female RG turn into a male.

Minh

[Ninong]

Minh,

No one is disputing your observations. The study is what it is. During a period of five months without a male, none of the females in their control group changed sex to male. That is what they observed.

They also examined the gonads of some 167 specimens to reach their conclusion that G. loreto is not a protogynous hermaphrodite. I'm not qualified to repeat that part of the experiment although you might be.

Whether they keep reef aquaria or not really doesn't affect the trustworthiness of this sort of a study. That's not to say that as hobbyists, we don't sometimes observe things that are not predicted in the scientific literature. I observed a mature female Cirrhilabrus scottorum begin the sex change process within a couple of weeks in my aquarium without a male present. I introduced a supermale five weeks after placing the mature female in the tank and all hell broke loose. "She" nearly killed him and kept him captive in a hole for ten days before allowing him to venture out. "She" had not even completed the male coloration change at that time. It took her a good two months for her dorsal fin to change from female yellow to supermale navy blue (this is the Australian variant). The former female remained as the dominant male with the newer supermale as the submissive male. I have to say submissive male because he did not loose any of his supermale coloration.

I checked with three recognized authorities on this. I even emailed several photos of both fish to an expert in Australia. All three told me that it is impossible for a terminal phase supermale fairy wrasse to revert from male to female. And based on just the coloration alone, I would agree with them. But... After 10 months of this relationship, everything changed. Both fish began acting very lovey dovey with each other. They began resting side by side on the sand bed just outside the sleeping cave of the previously dominant fish. They would just lie there with their sides actually touching for sometimes a full minute or more before swimming off. The previously dominant fish no longer engaged in the obligatory ritual chase of the other fish. In fact, I even observed some carouselling behavior. Chases were now slow motion follow the leader exercises in which they would sometimes change places.

I did not observe spawning behavior but I observed pair bonding of some sort. This has not been reported in the scientific literature that I am aware of.

[Minh Nguyen]

Originally Posted by Ninong

Minh,

.....During a period of five months without a male, none of the females in their control group changed sex to male. That is what they observed.

...........

Whether they keep reef aquaria or not really doesn't affect the trustworthiness of this sort of a study. ........

I do not agree with you on this point. If RG change sex, it is due to environmental stimulation or lack of stimulation. The environment and the health of the fish in the study have everything to do with the trustworthiness of the study.

Regarding the dissection of 167 RG (poor fish), if they cannot tell male and female apart, then how can they make any conclusion as to which gonad they look at belong to future males, future females, lesbian or gay fish? The obvious conclusion here is that they group the fish according to what the gonad look like. Their conclusion is very subjective, and not anywhere near as strong as you think it is.
Did you know that if we give human male estrogen, they will have breast development until they have typical female breast? Also, if a human female was given testosterone, her clitoris will develops into a penis?

All I can say is that I am likely observed these fish lots longer than these Scientists (from 1998-2004). I am well verse in Scientific Methods. Their conclusion (I did not read the study, only what reported by you) did not agree with my observed fact that my female RG (she had eggs that hatched) later turning into a male RG (he fertilize eggs of other RG and these eggs hatched). Their conclusion is obviously wrong because I know I am right in this case. This causes me to question their methods.

For obscure, unimportant and not newsworthy information like this, there is no other study to confirm this information. A long time ago, one of my professor told us in a lecture that it is likely at least 1/2 of the information in text book (medical sciences) are wrong. He wanted us to not trust blindly. We got to question 'the truth' when appropriate. In scientific literature, there are plenty of studies from major journals that later cannot be confirm or repeated. Certainly there are more than a few researchers fake and change their data somewhat to get them to fit a conclusion that they have decided upon. These researchers conclusion regarding RG was so wrong according to my observed fact that I think this is one of the most likely explanations.

This is all I got to say in this case. I always love a discussion with you on this and other reef boards.

Minh

[BubbaWPB]

Ahhh... the world of science... some of the facts that were true yesterday are just plain wrong today. Now, what is it that we know to be true today that will be wrong tomorrow? That is the question!

Very interesting and stimulating reading. Thank you both for your input.

[Ninong]

Minh,

As I said before, I'm not questioning your observations. As yes, of course I know what happens when you administer estrogen or testosterone. As you almost certainly know, it is the production of MDI (Mullerian duct inhibitor) at 13 weeks that causes the degeneration of the Mullerian ducts (female) in human embryos and causes the gonads to produce testosterone causing the Wolffian ducts (male) to develop into male sperm collecting apparatus. We are all born with both male and female ducts and it is the XY chromosome that causes the gonads to produce MDI. Absent the XY chromosome, there is no production of MDI and the Mullerian ducts develop and the Wolffian ducts disappear and the baby is a girl.

Basic human embryonic internal sex is female; male development depends on the production of the hormones testosterone, HDT and MDI. It is the release of male hormones that causes the clitoris to develop into a penis and this process doesn't begin until the 13th week.

In humans this happens starting at 13 weeks after fertilization. In Gramma loreto they are claiming that the same thing happens in juveniles prior to sexual maturity.

Maybe you can get a copy of that journal, although I doubt it. They would probably wonder what you wanted with a fish journal.

[Minh Nguyen]

Ninong,
At least I got you and some other people to not completely accept the results of the study as truth. To me, it is a fault study due to its wrong conclusions.
Minh