Some Sort of Physiological Domino effect. Pheromones........

[mauriciodelamaza]

Some Sort of Physiological Domino effect. Pheromones, allelopathy or visual stimuli?

A few days ago a pair of Herichtys sp ‘pantepec’ was formed in my well supervised community cichlid aquarium. Since I keep quite a few rather aggressive species, I have normally opted for the “democratic aggression management approach” in which tanks are loaded almost to their limit, allowing aggression to distribute evenly amongst its also evenly sized inhabitants. The above until Mr. Cupid arrives, and a newly bonded pair of community members starts beating the heck out of everyone else, turning the balanced and democratic regime into a despotic almost medieval one.

In the light of the above, my juvenile H. pantostictum (plural) ., remaining H. sp. ‘pantepecs’ and T. meekis were carefully re-distributed in other spare tanks, and the 55 gallons was left to the “newly wedded” by themselves, in the company of some dithers to take the abuse.

It is what happened in one of those tanks the marrow of this post….. In it the following distribution resulted (bee-nest-type light panels were used for division):

(a) Section a: a female H. carpintis with larvae in a not-yet-free-swimming phase.
(b) Section b: a male H. carpintis, father of the mentioned fry whom had to be separated from the female due to aggression as he tried to take over the female’s role.
(c) Section c: a female H. sp. pantepec in normal coloration.
(d) Section d: a male H. sp. pantepec who hates and will attack anything fishy that moves especially female pantepecs. He also in normal coloration.

Given that I am not too interested in keeping the H. carpintis’ fry, I did not seal any compartments between their section and the others. I figured that the fry would turn to be an excellent source of protein. This is a practice that I have followed many times before, when I am overloaded with fry. Normally, as the fry enter the quarters of another cichlid, they are immediately devoured.

As expected, fry were three days later in a free swimming stage, and as expected, they entered their father´s quarters. Also as expected, he immediately began caring for them, and keeping them near the food, and away from the hungry pantepecs on the other side of the “fence”.

A couple of days more and “pop” was no longer able to control his “children” who decided to move like a mosquito swarm in every direction, including the neighbouring pantepecs’ quarters. It is at this point that I was surprised by what happened: THE PANTEPECS WENT OVER NIGHT DIRECTLY FROM A NORMAL COLORATION INTO A BREEDING COLORATION WITHOUT EVER SHOWING ANY COURTSHIP OR EVEN SPAWNING CONDITION (THE FEMALE WAS NOT ROUNDED LOADED WITH EGGS), GENITALS (OVIDUCT OR PAPILLA) WERE NEVER APPARENT. THEY THEN ADOPTED THE WONDERING FRY, BREAKING THE BIG “SWARN” INTO SMALLER ONES, AND ADOPTING EACH A SMALL SHOOL OF FRY WITHIN THEIR RESPECTIVE QUARTERS. Now I have a set of separated angry Biological parents, and two separated foster parents who also seem to hate their guts, each taking care of a portion of the fry.

Yes, I know what you are thinking. Fry adoption has been recorded plenty of times, and has been amply studied for some time now. There is even an excellent article about it here in the CRC. However, it is not the “adoption phenomenon” that called my attention, but the rapid over-night change in dress and behaviour in fish that were not even physically together, conditioned or ready to breed (and they actually never did!!). They were in absolutely normal coloration immediately before this event. Not even subtle courtship on behalf any of the two was present.

The above only leads me to hypothesize over the subjects of allelopathy (as in plants), pheromones and/or visual stimulation of the hypothalamus, which may have lead to the “pseudo-post-spawning” behaviour and rearing physiological state (skipping the whole courtship, spawning and egg caring stages).

What triggered such behaviour in the adopting parents: (a) the presence of the fry, (b) the presence of pheromones diluted in the well circled aquarium water, (c) the presence of the Biological parents, or (d) all of the above?

From a pragmatic perspective, I believe the above could have some practical uses if, through the presence of a couple of the easier-to-breed-pair of cichlids one could synchronize the sexual cycles in a pair of rare, expensive or difficult to breed type, avoiding the more complicated and home-aquarium-unviable-parentheral-hormone-treatments used in aquaculture, and instead recurring to this sort of Domino-Physiological-Effect (if it could be somehow managed).

Has anyone had this same experience? Could anyone who knows, or understands the physiology of reproduction in cichlids explain actually what really happened physiologically-wise? Has anyone any thoughts?

Thank you very much

Yours

Mauricio De La Maza

[Victor]

Hello Mauricio,

I apologize for the answer delay, but I haven’t been around this forum in a while. Even tough I am not a fish physiologist / endocrinologist per se, I will try to comment and contrast your post in a theoretical-practical way.

The role of the two major chemosensory channels, olfaction and taste (this last one mostly in anosmic fish) in every aspect of the fish reproductive process has been demonstrated in numerous experiments. Hormones and their metabolites commonly serve as reproductive pheromones in fish. Such pheromones and other related chemical substances have been found affecting directly matting behavior and parental care processes. It also has been demonstrated that, for example, exposure of males to water holding a gravid female, educes courtship behavior. Is perhaps one of the best ways to explain hybridization when (usually) in a closed system (aquarium) there is only one individual (or one gender) of several different species of more or less related cichlids, and then a gravid female arouses (ready to rumble) and a dominant male diminishes his aggressive mode towards her, and switches to pre-spawning mode. This is due in part because ovarian pheromones not only stimulate courtship behavior, but also inhibit the male aggression toward the female. These pheromones are used by both sexes to incite the opposite sex to engage in sexual behavior, being at the same time this sexual behavior a direct regulator of endocrine secretion. Androgen conjugates in males and oestradiol and testosterone glucuronides (typical ovarian pheromones) in females, (among other sex steroid hormones), are known to trigger courtship behavior by means of influencing olfactory mechanisms, probably mediated by steroid feedback on brain areas involved in control of the olfactory bulb. At the same time, courtship behavior and visual stimulus influences in the secretion of the aforementioned hormones/pheromones.


In my own experience, I have observed a similar scenario to yours. In an aquarium with various formed pairs of the same species, is not rare to observe reproductive behavior of two or more pairs of the same and closed related species at the approximate same time. In an 800gal (120’x48’x32’) containing various Archocentrus and Cryptoheros species, formed pairs -of the same species- defending territories tend to spawn almost at the same time. In this particular tank, water changes are seldom, due in part to an effective bio-denitrification system and a tight fitting cover. Thus, the chemical metabolites (hormones, pheromones, ovarian substances, egg substances, embryo substances, urine, and the like) must remain “actives” in the system until they either decay or are metabolized and decomposed by bacteria, adsorbed by filtering materials, or combined into other chemical structures. Obviously, temperature, photoperiod, water changes, food availability, etc., are the first to “ignite” the “first secretions” and visual displays; but after one couple has started, is not rare to watch, within a few days interval, other(s) pair(s) doing the same. To be able to observe these patterns I have had to wait some years in order to provide enough space (for multiple territories to occur) in the form of big aquaria, but in your case, a similar scenario has occurred with a 55gal and three egg-crate dividers.

I think that being your 2 pairs closed related, perhaps not even being a different species but just subspecies, races or a case of geographic variability…? (Oh taxonomy, taxonomy!) , is not unusual that some substances produced by one pair were effective in triggering a particular behavior in the other couple.

Nevertheless, some particularities in your “experiment” have awaken some curiosity and by “domino effect” , some other questions.

When you refer to the Herichtys sp ‘pantepec’ male, you mention that he will bite everything he can find, specially females of his own species. This is a fairly common conduct in anosmic males, who despite their visual capabilities are not able to channel aggression, even toward gravid females. Even though his inability to cope aggression toward the female, he manages to change his condition and develop a “fry guarding” behavior and color pattern. Perhaps the visual stimulus was the trigger. Maybe he is not anosmic and just has a non-adaptative particular behavior toward the females. As we get involved more and more in the study of fish behavior, individual variability is an area that will emerge powerfully. Not just fish from the same species differ morphologically, but without a doubt they present different ethograms given the same environment and choices.

In order to establish the hierarchical contribution of stimuli (visual vs. odor), it would be interesting to include variations in the experiment design. For instance: substituting the egg-crate dividers for other opaque surface that would allow water transfer, but would incapacitate any visual interaction to verify the “olfactory hypotheses”. The other variation would be, either to place 2 aquariums together and allow only visual cues to occur, or sealing 3 partitions of glass in the 55gal to verify the “visual hypotheses”. In both cases the fry would be placed manually in each compartment and the resulting behavior recorded.

The fact that the two ‘pantepec’ developed their fry guarding coloration and did neither show any other previous pattern (pair formation displays, egg incubation, etc.) nor sex physiological character (genital papillae, pre-spawning or courtship variations in coloration, gravid female, etc.), and being the “absent” male androgen secretion directly involved in the control of the pre-spawning and spawning behavior, as well as all secondary sex effects like the apparition of the genital papilla and the nuptial and breeding coloration (that you could not detect), lead us to think that, either there are perhaps some sort of postvitellogenic substance (pheromone) or some fry secreted chemical (pheromone) that could trigger the ‘pantepecs’ behavior, or the visual stimulus of the fry is triggering the fry-care conduct, or is perhaps a mix of both visual and odor stimuli. Also the presence, as you mentioned, of the biological H. carpintis parents (visually and chemically speaking) could have been participating in the ‘pantepecs’ response.

About your “pragmatic” approach to induce hard-to-breed” species with the presence of other easy-to-breed breeding species, I’m not sure to what extend olfactory pheromones are transferable inter-specifically. All I know about pragmatism, tangibility, and the like, (in this case) is that… after a good “bath” in MS222 and a proper injection, either with pituitary carp extract, human chorionic gonadotropic hormone… females of most fish species get gravid, and male testes get full. On the mean time, experiments like yours could help to shape “other kind” of practical protocols with reasonable results for the aquaculture business based on pheromone activity instead the classic hormonal induction, as well as opening a door for the hobbyist that cannot get legal access to such hormones.

And now, after all this long “mess”, like most Sundays, it is time for me to take care of some major cleaning/water changes.

Talk to you soon.

[mauriciodelamaza]

Dear Victor,

First of all thank you for sharing your most interesting response, and for taking some of your Sunday time off to analyze my post and to prepare such enlightening comment. While I am also not a fish physiologist and less an endocrinologist, I do have some –rather not in use for some time now- experience in applied animal reproduction, mostly on higher taxa (basically poultry, cows and mares), so from your comment and my limited experience I will try to recapitulate over some of the issues that have been covered here by extrapolating from some of my experiences and “cross pollinating them” with the issues that you brought up in your response. Please feel free to correct me, as I am learning here.

1. If I understood well, under “normal” circumstances, environmental hypothalamic stimulating factors such as photoperiod, thermo-period, the presence of other fish and a proper dietary conditioning -with a diet rich in protein and vitamins- may lead one or more females to begin the production of LRH and the consequent stimulation of the pituitary gland. Such state triggers a sort of “virtuous cycle” in which the Folicule Stimulating Hormone (FSH) and the Luteinizing Hormone (LH) induce the ovaries to growth -and gravidity- in the first case and to the production of ovarian hormones in the second.

2. The ovarian production of steroidal hormones including oestradiol and testosterone glucoronides on the one hand further stimulate the pituitary gland, and on the other, are released into the environment –both in a “pure” form and/or as metabolites- where they function as olfactory mechanism stimulants which are captured by receptive male(s) by means of two major chemosensory channels: olfaction and taste. Such pheromones appear to trigger courtship behaviour which is mediated by steroid feedback on brain areas involved.

3. Males are stimulated in an analogous form to females by the same initial triggering factors plus the female’s visual stimulus, and the production of androgen conjugates is further enhanced by the diluted female pheromones which “float” in the aquarium water, thus lowering aggression on behalf the receptive male towards the gravid female, and triggering courtship behaviour, closing in this manner the first stage of the reproductive cycle as soon as both synchronised future parents “decide” that they are ready to spawn.

It also becomes clear from your post that sometimes something can “go wrong” along the way as individuals with particular physiological/behavioural patterns and/or disorders – which keeps reminding me of us humans - may present a deviating conductual ethogram due to failure of e.g. olfactory receptors (anosmism) amongst other possible causes which may manifest as an apparent over aggressive behaviour which seems rather common in Herictys sp. pantepec, which is rather difficult to spawn in comparison to H. carpintis (Although at this point I would prefer to keep away from taxonomic matters ).

It is at this point that from my experiment and your post -reproductive behaviour in your 800 gal tank- I have concluded a couple of issues:

1. In fish, as in higher taxa, unwanted pseudo sexual/breeding behaviour can be induced through voluntary or involuntary (e.g. the case of my experiment) “administration” of the “wrong” behaviour associated hormones (oestrogens and androgens amongst others) vs. actual cycle-inducing (synchronising) hormones e.g. human chorionic gonadotropic hormone (hGC), pituitary carp extract, LH/FSH, etc. and/or the more traditional artificial control of the aquarium “environmental” factors.

2. Unlike higher taxa, pheromones, whether released by the parents, by the fry or by vitellus seem to play a significant role in the aquarium which goes far beyond the simple recognition of a receptive female by the male.

3. It could be hypothesised that the “domino effect” could actually be used by those that have no access to hormones provided the fish intended to actually catch the “hormonal ride” are of a closely related taxa, are already conditioned to spawn, and just need that little extra “push”.

Now, just as a closing statement, believe me, I am going to try your proposed variants of the experiment as the opportunities present. Maybe something interesting can come out of it all!!

Finally, as you probably figured, I am currently working in a limited space with species that are sometimes a little bit reluctant to spawn, plus it becomes a bit difficult down here to get “rid” of the surplus fish. Also, I do have legal access to the mentioned hormones and pharmaceuticals including MS222, hGC, and PMSG (not mentioned, has anybody tried it?). However, I have no access to the pituitary carp extract. In your experience, and since you mentioned it, how does one compute the dose to be injected? Does one treat both the male and the female? Is there a published protocol that may be followed?

Again, thanks for your response.

Saludos,

Mauricio De La Maza

[Victor]

Mauricio,

I think that, not just your understanding was right on the trail, but you enumerate some animal physiologic processes in a such clear matter, that ultimately it has been a learning experience for me.

In your first post you were requesting information about these processes when you mentioned ask if: “Could anyone who knows, or understands the physiology of reproduction in cichlids explain actually what really happened physiologically-wise?”. I don’t remember giving any comment to that question, far from the first long paragraph, where I included mere comments-examples of how we know, based on recent findings in peer reviewed literature, that there is a relationship between “fish produced chemical substances” and “behavioral response” in fish (or pheromonal activity), as well as a relationship between certain “behavioral displayed patterns” and “hormonal production-secretion” in fish. Thus, I honestly can’t find a direct relationship between my post and the detailed understanding you extracted from it.

At the beginning of my previous post I tried to nibble some common present knowledge extracted from different articles I have read, aiming mainly to illustrate this mix of ideas in a divulgative fashion; avoiding by all means to get involved into a physiological treatise type of conversation. This avoidance was mainly due to being an outsider of the discipline I would have to, pretty much, “copy and paste text” from serious sources, and in general, because I don’t think that I have the necessary background in organic chemistry to follow a deeper conversation in this area of knowledge. Perhaps your knowledge in applied animal science (animal science, veterinary science) gave you the bases to furnish such a detailed description of the physiological processes.

Getting back to your questions.

I have never seen PMSG in the ichthyology lab (back in Spain). At those times we used to induce fish with human corionic gonadotropin (hCG) and pituitary carp extract (CPE). My wife (a veterinary doctor) told me that it is fairly common sight in Europe, but she never dealt with fish, aquaculture, or similar scenarios. I’m also not sure if it is a common inducer in American fish farms.

Pituitary carp extract is a widespread inductor in fish farming operations (mostly in developing countries, due in part to the lower cost and easy purification) I remember to induce small cyprinids, and even cyprinodontines! Lebias ibera (=Aphanius iberus) with CPE. Dose tables for different species must be all over the web, just google for them. And remember that perhaps (mostly if you are dealing with really small fish) you’ll kill some individuals ‘til you get the right dosage. As we know being cichlid hobbyist, fish dead it is just the intrinsic part of the game we face, pretty much every time we want to obtain any goal with fish in captivity . If you are going to induce cichlids, take into account that perhaps 2 injections (doses) in a couple of days won’t just do it. Keep up trying.

I have some questions related to ecological-behavioral area:

You were mentioning about the difficulty to breed ‘pantepecs’ in contrast with the easily breedable carpintis. Do you think that it is just a matter of the environment provided? Is this a common behavior in nature? Why do you think that the male ‘pantepecs’ are less lenient with their own females that with any other fish, even males ‘pantepec’? Do you think that this overly aggressive version of the cyanoguttatum-carpinte group has found a way to create a behavioral-isolation-type-of-barrier and a niche, in order to avoid hybridization with similar Herichthys spp. by means of simply being a “tough cookie to handle”? Have you found any noticeable differences in the nuptial, territorial, and spawning displays between the ‘pantepecs’ and H. carpintis?

Un saludo Mauricio

[mauriciodelamaza]

Hello Victor,

Again thanks for your response. Regarding your questions, I will try to answer them to the best of my knowledge. Unfortunately, the pantepec Herichtys as well as the cazones have become a bit difficult to study in their natural environment due to basically three factors:

1. As I stated in my article, local people seem to constantly abuse these wonderful fishes’ parental behaviour and spear them as they become easy targets while trying to protect their fry. While such type of fishing “art” is actually outlawed in Mexico, it is difficult to fight against such deeply rooted customs and traditions; laws are not properly being enforced, and I suppose most believe that there are social priorities and “more urgent” matters to be covered in our developing country before looking after the welfare of an unknown population of fishes .

2. Pollution and the introduction of exotic species have also taken a toll on the populations of native endemic fishes.

3. The above has leaded the fish to look for areas where they cannot be bothered by humans. Such areas unfortunately for fish-watchers are sections and affluents of the basin with very low or null visibility; and in the case of the colourful Metlaltoyucan population, the ponds in which a most strange “symbiotic” relationship has developed between crocs and fish ……. No one dares to dive in the crocs ponds where there have been a couple of attacks in the last years. Another survival strategy around the city of Alamo seems to be the arrival to sexual maturity by cichlids at a very small TL, while they are not yet attractive to humans for food.

In my experience I have had some difficulties spawning pantepecs in my aquaria, in contrast to most other Herichtys –including carpintis- that I have kept, where basically all I do is set my heater right, play with photoperiods, frequent water changes, feeding with high protein content, lots of hiding places and waiting for three to five weeks for nature to take its course .

Such difficulties mainly reside in the very well established intra-specific hierarchical order that develops in which a dominant male takes over the whole aquerium and starts assaulting everyone else –mainly intra-specifically (they do have a little bit more respect and tolerance for other fish –including other Herichtys cichlids), or ultimately killing himself in some sort of violent accident product of its violent behaviour. As soon as such dominant male is out, the next one in line –or even a dominant female- takes over and starts behaving in a similar manner and so on.

I lost six fish –including dominant gravid females full of eggs- in such ways as they were either killed by their fellows, buried themselves under a large rock as they dug under it unlike any other cichlid does in my tanks –they even seem to play around more so than the other Herichtys species with the decoration-, or simply banged themselves to death against the egg crater separation.

The above lead me to try quite a few variants of the “incomplete divider technique” until I finally decided to place two potential breeding pairs in a really overcrowded with other cichlid species, but well supervised aquarium……... As soon as I noticed a subtle element of courting behaviour, interestingly BETWEEN THE TWO NON-DOMINANT FISH, I took everyone else out and left nature work its ways…………. Since then the pair has formed a very strong bond, and the fry are doing excellent.

1. Is it just a matter of the environment provided? It is difficult to tell. I recently gave my friend Marco Arroyo six F0 pantepec juveniles (1 to 1.5 inches) and he has already reported more aggression in their growing tank than in its neighbouring H. carpintis and H. pantostictus of similar sizes. So maybe it is indeed an evolutive inheritable trait.

2. Is this common behaviour in nature? It is difficult to explore given the aforementioned circumstances, but the fact that some populations breed in turbid waters may be the key to solving the mystery. Could it be that too much visual stimuli favoured by the clear water in the aquarium triggers the aggression?

3. Could such behaviour be a way to avoid hybridisation with other Hericthys? I do not believe so, for these are endemic populations which are separated from other Herichtys by important physiographic barriers. Under natural conditions they would never come in contact with other non- tokogenetic groups.

4. Is there any differences in nuptial, territorial and spawning displays between the pantepecs and H. carpintis? Yes, indeed there exist quite a few subtle but well marked differences, some of which are the subject of the research that I am currently doing together with Juan Miguel.

Talk to you soon

Saludos,

Mauricio De La Maza

[nasirjmk]

Dear ,

Can you help me out in prescribing me the name of medicine name that can bring breeding condition promptly to my redhead cichlid i want to breed them they are too aggressive with each other and I want to induce hormonal medicine to bring the in breeding condition. they once bred .

Please help me out in this case promptly.

Regards

Nasir
jamnasiralliani@gmail.com