getting the hump!!

[RD.]

Relax, no need for anyone to "defend" anything, I was simply asking a question.

As you can see the link that I supplied also references some of George Barlow's early work with amphilophus, as well as one of his colleagues from the University of California, Berkeley. In neither case is it as definitive as you stated, that being that no females in the wild grow humps, or that in the wild females with humps do not reproduce. One can simply not extrapolate that conclusion from the information supplied via that study. That is precisely why I asked for your reference to that information. Clearly what takes place in captivity cannot always be extrapolated to what takes place in nature, including the massive "grotesque" nuchal humps that George mentions in the link that I supplied.

As far as what nuchal humps are mainly comprised of, certainly fat makes up some of the hump, as does tissue, but the sudden increase in size is due to fluid, not tissue, or a sudden increase in fat. I'm sorry, but to state that the nuchal hump is nothing more than fat deposits, is simply incorrect. See below ......

In flowerhorns the nuchal hump shown above would be considered a hard kok. One that is mostly comprised of fluid (generally the largest nuchal humps) are referred to as water koks.

This is exactly what Bleick was referring to in his paper when he stated:

Plasma water increases slightly in fish with a nuchal swelling, indicating systemic water retention.

from the abstract ............

Abstract

A nuchal hump (forehead swelling) develops in both male and female Cichlasoma citrinellum prior to spawning, and subsides shortly after spawning. Hump development is due to edema of the modified nuchal hypodermis. Fat stored in the same tissue does not contribute to prespawning hump development, although it may cause a residual, enduring hump. Plasma water increases slightly in fish with a nuchal swelling, indicating systemic water retention. The prespawning nuchal edema resembles preovulatory sexual skin swelling in monkeys. Nuchal hump development in males is gonad dependent.

A hump could be induced with mammalian gonadotropins (HCG or ovine LH) in intact males but not in castrates. However, the steroid hormones testosterone, 11-ketotestosterone, 17β-estradiol benzoate, progesterone, hydrocortisone acetate, and aldosterone failed to induce a hump. A decline in the hump comparable to that occurring after spawning was induced by homogenate of C. citrinellum rostral pars distalis (8 r. p. d. per male fish); and a slight effect was obtained with ovine prolactin (2 daily injections of 7.5 μg/g). These results suggest that PRL secretion may inhibit the hump during the parental period.

HTH

 

[Anchovie]

I wasn't taking a jab at you at all sorry. When I said the hump was just fatty tissue I didn't go into detail that it was tissue that is able to be inflated via fluid, but the op didn't ask for a full chemical makeup of the hump. I guess I shouldn't be so definitive when saying which fish will reproduce, but the studies have shown that females with humps are less desirable. I should choose my words more carefully and for that I apologize. I love a debate.


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[RD.]

No worries, it's all good.

 

[Miguel]

I love a debate on this theme of ours!

The only thing I find, empirially, Neill and Anchovie, is that males with big humps my have them diminish but never disappear.

Even solo humped males, without females, keep the humps, one day smaller,next day larber.

But yes, Neill, is right, it is mostly water, because the hump itself is soft as soft can be, if you actually touch it..