Estivation question

[Namio]

Hi desertheat, to answer your question I totally agree with Grif, Lija, and Carlos that You wouldn't have to estivate your frog. On a side note, I agree with Carlos that Jakub has made some intriguing statements regarding his experience relating to estivation and better immune system (?). I'm too hoping Jakub would touch more on that subject.

[Lija]

I'm very interested in it too, there should be something that Jakub noticed that makes him think this way, very interesting statement.

I'm just thinking to make any correlation between better immunity, lifespan and aestivation you should have 2 huge control groups that have identical or almost identical genotypes, keep them in exactly same conditions starting from egg, feed exactly the same, maintain same activity level ( no breeding). And record all findings through their all life, so the whole process might last 20+ years... But how interesting it would be!

[Mentat]

I'm very interested in it too, there should be something that Jakub noticed that makes him think this way, very interesting statement.

I'm just thinking to make any correlation between better immunity, lifespan and aestivation you should have 2 huge control groups that have identical or almost identical genotypes, keep them in exactly same conditions starting from egg, feed exactly the same, maintain same activity level ( no breeding). And record all findings through their all life, so the whole process might last 20+ years... But how interesting it would be!

You are on right scientific track Lija; but actually think could be simpler and smaller using small sample statistics. The origin could be equalized among frogs by using brothers and sisters from same litter born at same time in year as wild stock. So let's say we start with 48 babies. As you stated, all will be brought up exposed to same food, enclosure type, and environmental conditions. Then around 6 month mark we could assign frogs into 4 subgroups of 12 frogs each, populated by both male and females. Two of those groups will be estivated and 2 used as non-estivated controls.

At 6 month mark; we would expose 1 subgroup of each estivated/non-estivated groups with a know non-lethal parasitic pathogen found in wild populations (sorry but it's science ). Then around same age they estivate on the wild, we would induce estivation in two of the sub-groups (one infected and one non-infected). Once we bring out of estivation, can conduct fecals on all frogs and see if there is a difference in the parasite population between estivated and non-estivated frogs. So in a bit over one year we start gathering data !

Then for a couple months can start making comparisons in regards to overall health, growth, etc. Scientist can play with many variations like pathogen type, response to treatment, breeding a group, etc. and keep interest several years; but should have lot's of raw data to draw a basic conclusion in like 3 years or even in less if starting with larger groups. Think this could be a fun herpetological thesis project if it wasn't for the couple years required to conduct it.

Still hoping Jakub shares more of his observations with us. There are many subjects science has not looked at (like in this case) or does not have the measuring capability to prove or disprove; but we can still gather great knowledge from observation .

[GrifTheGreat]

It would take a bit longer. The frogs would need to be at least 1 year to 1.5 years of age for the safest Aestivation due to young frogs dying prematurly during dormancy. It has been found that a cool down does help the frog heal. Being exposed to slightly cooler temps can assist in healing and fighting disease. Makes sense because most bacteria and viruses require a certain temp in order to replicate and attack the body. Without the needs of the pathogen met it will not be able to get a foot hold on the frog and the frog"'s immune system can iradicate it accordingly.

Edit; Just to elaborate. Cool down does not mean Aestivate. Lowering the ambient air temperature not to iduce a dormancy period.

[Namio]

Carlos just opened a can of worms (Jakub, too, in that regard). Excellent approach and input from both Carlos and Grif. I suppose we can agree on raising a frogs to at least one year of age before attempting estivation. I'd recommend to have more than one clutch of tadpoles--the more the merrier! But often times researches are limited by money, time, and space.

I was thinking somewhere along the line of what constitutes a frog's immunity. Frog immunity has two components--innate and adaptive responses (see below for more details). First it lies on their skin. The innate immunity is determined by the antimicrobial peptides defenses. It can be quite simple as most of those peptides have already been successfully isolated and sequenced. And the innate immunity can be determined by the production/concentration of these peptide defenses. With PCR (DNA replication) and genetic sequencing, we can test for significant differences in the concentration of antimicrobial peptides produced by individuals in our control (no estivation) and treatment (estivation) groups. This part is nice and clean for a scientific study. It is when you have to start introducing pathogens to frogs that it gets tricky, because the variables multiply.

This brings me to my next point, the adaptive immunity. This is the second defense mechanism that will kick in when the innate immunity (skin peptide defenses) fails. It's initiated by T and B lymphocytes (commonly known as the white blood cells). It gets trickier because we now need to test frogs with different kinds of pathogen, with the same amount of exposure & period, and how these frogs respond. Assessing how well the frogs are handling the infection is also tricky. Carlos had already provided us with parasites and fecal matter counts, which is great. However, there are many types of pathogen that may need to be included. Bacterial, viral, fungal, and etc. Do we assess success and failure by death? But if they all live, then do we do it by weight loss? For sure tricky business. Especially after the first part we may not have frogs left to test the second part due to the lethal nature of the conventional PCR. Not sure if non lethal swabbing (real time PCR) is an option.

[GrifTheGreat]

Carlos just opened a can of worms (Jakub, too, in that regard). Excellent approach and input from both Carlos and Grif. I suppose we can agree on raising a frogs to at least one year of age before attempting estivation. I'd recommend to have more than one clutch of tadpoles--the more the merrier! But often times researches are limited by money, time, and space.

I was thinking somewhere along the line of what constitutes a frog's immunity. Frog immunity has two components--innate and adaptive responses (see below for more details). First it lies on their skin. The innate immunity is determined by the antimicrobial peptides defenses. It can be quite simple as most of those peptides have already been successfully isolated and sequenced. And the innate immunity can be determined by the production/concentration of these peptide defenses. With PCR (DNA replication) and genetic sequencing, we can test for significant differences in the concentration of antimicrobial peptides produced by individuals in our control (no estivation) and treatment (estivation) groups. This part is nice and clean for a scientific study. It is when you have to start introducing pathogens to frogs that it gets tricky, because the variables multiply.

This brings me to my next point, the adaptive immunity. This is the second defense mechanism that will kick in when the innate immunity (skin peptide defenses) fails. It's initiated by T and B lymphocytes (commonly known as the white blood cells). It gets trickier because we now need to test frogs with different kinds of pathogen, with the same amount of exposure & period, and how these frogs respond. Assessing how well the frogs are handling the infection is also tricky. Carlos had ady provided us with parasites and fecal matter counts, which is great. However, there are many types of pathogen that may need to be included. Bacterial, viral, fungal, and etc. Do we assess success and failure by death? But if they all live, then do we do it by weight loss? For sure tricky business. Especially after the first part we may not have frogs left to test the second part due to the lethal nature of the conventional PCR. Not sure if non lethal swabbing (real time PCR) is an option.

Well the main problem is that all pathogens that infect frogs can be lethal to them. There is no such thing as nonlethal pathogens when it comes to amphibians. All are potentionally fatal without treatment.

[Namio]

Yes I agree that many pathogens can be lethal, but more often that they are not. Take chytrid for example, it is devastating populations in the tropics, but outside of the tropics most amphibians are living with the infection and does not always develop chytridiomycosis, the lethal disease. How do I know that? There is plentiful evidence that chytrid is globally distributed to the point that if there's amphibian, there's chytrid, and yet records of mass extinction and population declines have only been observed in the tropics. What about those that are infected in the neotropics and temperate zone? Many of them live with the infection. Ranavirus is another good example of a potentially lethal pathogen that are not usually lethal.

Ceratophrys species on the one hand, are definitely vulnerable to chytridiomycosis. So I'm afraid chytrid infection will yield to high percentage of death.

edit: one question worth asking would be when a pathogen (e.g. chytrid) becomes pathogenic (e.g. Pathogenic).

[Mentat]

... I was thinking somewhere along the line of what constitutes a frog's immunity. Frog immunity has two components--innate and adaptive responses (see below for more details). First it lies on their skin. The innate immunity is determined by the antimicrobial peptides defenses. It can be quite simple as most of those peptides have already been successfully isolated and sequenced. And the innate immunity can be determined by the production/concentration of these peptide defenses. With PCR (DNA replication) and genetic sequencing, we can test for significant differences in the concentration of antimicrobial peptides produced by individuals in our control (no estivation) and treatment (estivation) groups. This part is nice and clean for a scientific study...

This is very interesting and would be cool to test both immunity levels, of control and estivated groups, after completing estivation and frogs are eating again. As a matter of fact, frog immunity as related to stress, could be another nice study. Many of our pets get all stressed out from shipment and new enclosures, not to mention all the stress from wild frogs capture, holding, and distributing. Comparing a stress free frog to one with simulated holding, shipment, and new enclosure could give out some interesting data that could be used to enhance a pet frog survival. We could see if either the innate, the adaptive, or some other unknown immunity factor is quickly affected and how to best deal with it .

Well the main problem is that all pathogens that infect frogs can be lethal to them. There is no such thing as nonlethal pathogens when it comes to amphibians. All are potentionally fatal without treatment.

Yes Colleen/Jerrod, and also frogs in the wild do survive with many of these local pathogens in their systems. As you mentioned before, cold might have to do with this, specially if we think of bacteria. Now my thought with intestinal worm parasites for example, would be that in nature, a frog would estivate during dry season with an empty intestine. Having no food source the hosted parasites would eventually perish and only some of it's egg forms would survive. When coming out of estivation, the frogs would be pretty much in a healthier state that when they started it . A similar process would happen to frogs that hibernate during Winter; with the frogs parasites not surviving cold temperatures and freezing .