Atmospheric pressure

[Joe Lydon]

Hello, Everyone! I'm new to the forum, but I've been lurking for a few weeks. I have received some very insightful information for the 40b reef build I'm doing for my daughter.

With that aside, I was wondering about atmospheric pressure and it's relation to the success of breeding marine fish. Considering the majority of reef action is at a depth greater than 10 meters, do you think our lack of depth is hindering our ability to reproduce with marine species? The thing that brought this to mind is my experience with breeding boa constrictor imperator. Although you can acheive some success year round, it is hit or miss. Courtship normally occurs once the barometric pressure drops. The significance in pressure change at these depths is such an environmentally different experience, that IMO, could very well be the reason for our success rate.

For years, I have wondered why nobody has really gotten the breeding thing nailed down. With the technology available today, it doesn't make sense. It would be so beneficial for our oceans and keepers (as captive bred normally thrive more often than wild caught), not to mention it would be quite profitable. It seems all of the motive is there, yet no results. Something is missing, they are animals and their single most important goal in life is to reproduce.

Any thoughts?:fish2:

 

[Joe Lydon]

Additional thoughts - Considering the vast majority of captive propagation has been with shallow water species, I think it backs my theory. It's the one thing that is always present, yet unseen and never measured in our systems.. We hear about everything from Nitrite to PAR readings, but when was the last time you've ever heard someone mention their tank's ATM capabilities? Think about fry that naturally hatch in 150' of water. Their biology has evolved to develop under immence pressures, they may not be equipped to develop in shallow systems. Even the bone density in Humans has been determined by the force of gravity, increasing or decreasing gravity will cause problems in the long run. I would be willing to bet, that under a pressurized tank system calibrated to the correct range of ATM specific to the species, would greatly increase chances of reproduction and rearing.

 

[billsreef]

Considering the majority of the specimens in the hobby are from shallow waters, less than 100'...probably much of that less than 50', I don't think water pressure is an issue. These are typically fish whose eggs and larvae exist in the surface waters where the plankton is at it's richest. For true deep water specimens, there might be something to that.

 

[Joe Lydon]

Granted 50-100' is relatively shallow in terms of ocean depths, but being a fellow diver, you can attest to the increase in pressure at 30', let alone 50-100'! With all other things being equal (nutrients, etc), pressure just seems too much for me to ignore. Even if it were used to make adults feel "at home" and induce spawning. With the lack of success of reproducing marine species in captivity, something is missing. I'm just trying to think outside the box. I haven't been able to find any info on the web talking about it. Under the right conditions, animals want nothing more than to reproduce.

 

[gbru316]

Granted 50-100' is relatively shallow in terms of ocean depths, but being a fellow diver, you can attest to the increase in pressure at 30', let alone 50-100'! With all other things being equal (nutrients, etc), pressure just seems too much for me to ignore. Even if it were used to make adults feel "at home" and induce spawning. With the lack of success of reproducing marine species in captivity, something is missing. I'm just trying to think outside the box. I haven't been able to find any info on the web talking about it. Under the right conditions, animals want nothing more than to reproduce.

The rift lakes of africa (malawi, tanganyika and victoria) are very deep, over 200m in places. Most cichlids are relatively easy to breed.

I don't think pressure is the issue. Marine life reproduction is often triggered by very specific events; tidal changes, moon phase, water temperature changes, to name a few. In captivity, it's nearly impossible to replicate all the subtle "cues" that are used for breeding.

 

[Joe Lydon]

I'm going to give it a shot, given it's a relatively easy science expirement. I just can't discount it until it's been tested. The comparison to Cichlids is like comparing boa constrictor imperator to python regius, although both are in the boidae family, one is a live bearer, one lays eggs. Not to mention their reproductive behavior is completely different. As I mentioned in my first post, although it is possible to achieve a succussful copulation year round with bci (exceptions to the rule), breeders prepare for "the season", when the barometric pressure drops. Seems you need that one special ingredient to generate consistency. Since hydrostatic pressure seems to be overlooked in breeding marine species, I have to do the best within my means to test it out! I will keep record and post information as it comes. It may be completely irrelevant, who knows?

 

[gbru316]

Any atmospheric pressure change that is experienced in nature is also experienced to the same extent in our tanks. The only difference is that gauge pressure in nature is probably greater than in our tanks.

Are you planning on putting tanks in a pressurized environment to simulate increased depth?

 

[Joe Lydon]

The plan is to pressurize the tank itself.. I already have an idea how to increase the pressure via compressed air. Building a system with water flow that will stand up to roughly 72psi is going to be the fun part. 72psi will create a hydrostatic pressure equal to 100' depth. I'm figuring lots of acrylic, schedule 40, a sealed hatch system, external pumps, ingenuity, trial with lots of error, may turn up some results! If not, I will keep myself busy trying!

Not to say 72psi is the golden number, it might be half that, or more. I would probably start with an increase of 1 atm every week or so.

 

[gbru316]

The setup sounds simple in theory, but I predict it's going to be rather difficult (and expensive, and possibly dangerous) in application.

Anyway, good luck.

What species are you experimenting with?

 

[Joe Lydon]

I haven't decided on the species yet. I guess it shouldn't really matter a whole lot, if I'm right? Even if I can do so much as increase reproductive activity in a species that has had little to none, I would be happy with that. I have no doubt others could do it better, and if I show any success, I hope others would run with it. I literally came to this forum because of the great minds! I was seeking opposition, debates, advice, etc. There is no progress without it!

 

[Curious George]

Anything to get breeding going in the hobby is helpful.

They are at it again, trying to ban collection in Hawaii and negatively impact the availability of animals to the aquarium trade. The more ideas, and the more breeding, the better.

The wackos are out again.