Rhaphiodon Vulpinus Reproduction?/Info

[Industrial]

So I have found an article written by people who traveled to the Tocantins river in Brazil to research the reproduction habits of the Rhaphiodon Vulpinus.



The study was done in a clearwater river. According to Mongabay, the Tocantins river is moderate current (not quite whitewater). Although rhaphiodons also occur naturally in whitewater as well.

From what I have gathered, raphs can be sexed by mature sizes. The males appeared to mostly top out at 14" and females are likelier to grow larger (up to 20"). Other sources have said that raphs can grow to be two feet. This study in specific was done on 2711 raphs.

Also, the more important thing, it looks like they just breed in the rainy season when the water rises. So it looks like all you would need to do is keep the tank from being full for a while then start adding water. Not to mention you will probably need a very large tank or more likely a heated pond.

Source article: http://www.scielo.br/pdf/ni/v5n4/v5n4a07.pdf

I think that this is very interesting, and hopefully will lead to some successful captive raph spawnings!
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[Cakilla]

Very interesting , thanks for the info

 

[sbuse]

cool...

 

[hybridtheoryd16]

Alot of other rain season breeders are successfully induced into spawning by temp drops done by cold water changes.

Of course they are probably egg scattering spawners. So you will need a shoal of them to increase chances. And a shoal of 14-24" raphs is unheard of so far in the hobby.

But it would be awesome.

 

[DB junkie]

People are going to have to care for them up to 14 inches before worrying about breeding. How often have they been available and how often are they grown to this size?

Did the study happen to measure the PH of the water they were found in?

 

[Industrial]

People are going to have to care for them up to 14 inches before worrying about breeding. How often have they been available and how often are they grown to this size?

Did the study happen to measure the PH of the water they were found in?

The study did not mention the PH, but I checked the PH of the rivers on Mongabay.

Tocantin River
pH 6.9-7.3, 5-12 dH, 75-82 F (24-28 C)

The Amazon, Napo, and Orinoco Rivers
pH 6.8-7.1, 3-8 dH, 79-84 F (26-29 C)

It looks like they prefer neutral PH, soft water and low 80's for temperature.


I don't think that they need to be fully grown to breed, I was having trouble understanding the sexual maturity sizes in the document. I'd say mimic rainy season every year until they breed. I don't think it's very possible to have a tank with fully grown raphs, but if you had a pond for 5-6 adults and egg laying it isn't that far fetched.

As for availability, my LFS has a tiny less than 2" raph right now. They also get shipments sometimes up to 10 raphs, sometimes up to 10 scombs. A few months ago they started getting some in for the first time since I started going there over the summer. They seem to be out now though, but they seem to be a fish that you can special order.