Amano Shrimp

[JoeD323]

I was helping a customer with some issues in his planted aquarium today and we got on the subject of Amano shrimp. He mentioned to me that, in his 75gal planted tank, he had introduced several Amanos some years back. The guy knows his stuff for the most part so I trust that he knows what kind of shrimp he has.

Anyway, he mentioned that over the past year he has noticed that a few smaller Amanos have popped up. Not many but enough to notice that there are shrimp of an overall smaller size mixed in with the large adults in his tank. Has anyone here heard of Amanos potentially successfully spawning in a freshwater environment?


Joe

[Geniusdudekiran]

I've wondered this myself. In my experience they give birth to hundreds of zoea (sp.?) at a time, so it would make sense... and if so, I wonder if a completely freshwater strain of Amanos could potentially be bred out by only breeding these?

[DerekFF]

I think in a very well established tank some may be able to make it to adults. Its not the first ive heard a story like that about amanos or ghost shrimp

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[AquaPipes]

I've heard anecdotal stories of this happening.

[Kitsune_Gem]

We got in a shipment of ghost shrimp at work with a mum about to pop. We isolated her and a few hours later we had baby ghost shrimp. The lived for about two weeks, and then I went on vacation and wasn't around to feed or do a water change for them, so they passed away. But the whole time they where kept in fresh water. So it may be possible.

[JoeD323]

Well its actually a common misconception that ghost shrimp require saline conditions to reproduce. The typical ghost shrimp seen, at least around these parts, sold as feeders are actually pretty salt intolerant. They do, however have a several day long larval stage.

Its interesting to hear that others have heard of this occurring in Amanos though. I am very curious whether or not this has been proven possible.

Joe

[jasonpatterson]

I'd be very cautious about believing it. Amano shrimp zoeas are not easy to rear even when you provide them with brackish water to develop; without brackish it seems very unlikely. For me to believe that it's true I'd need to see the shrimp themselves, to make sure that they're actually amanos, get a good count, and then come back at a later date to confirm that there are actual juvenile amano shrimp present. There is also substantial sexual dimorphism in amanos, so different sized shrimp in the population often means large females and small males mixed.

As JoeD said, the ghost shrimp thing is irrelevant. Most of the ghost shrimp that are sold are entirely freshwater.

Is it possible? Sure. Is it likely? No way. I'd love it if it were true though.

[Kitsune_Gem]

Originally Posted by jasonpatterson

I'd be very cautious about believing it. Amano shrimp zoeas are not easy to rear even when you provide them with brackish water to develop; without brackish it seems very unlikely. For me to believe that it's true I'd need to see the shrimp themselves, to make sure that they're actually amanos, get a good count, and then come back at a later date to confirm that there are actual juvenile amano shrimp present. There is also substantial sexual dimorphism in amanos, so different sized shrimp in the population often means large females and small males mixed.

As JoeD said, the ghost shrimp thing is irrelevant. Most of the ghost shrimp that are sold are entirely freshwater.

Is it possible? Sure. Is it likely? No way. I'd love it if it were true though.

The ones we get in I have drip accumulated into my salt tank systems for feeders. Theres a few that are still there and have been there for 4 + months now.

[sayurasem]

Nothing is impossible, just a high probability.

[jasonpatterson]

Originally Posted by Kitsune_Gem

The ones we get in I have drip accumulated into my salt tank systems for feeders. Theres a few that are still there and have been there for 4 + months now.

And that's why I said "most" and not "all."

[JasonG75]

WOW thanks for clearing this up...I thought Amano were FW shrimp, I guess now I know why I haven't seen any spawns yet.

[jasonpatterson]

Originally Posted by JasonG75

WOW thanks for clearing this up...I thought Amano were FW shrimp, I guess now I know why I haven't seen any spawns yet.

Amanos readily breed in freshwater, and the females will carry their eggs and the zoeas hatch out, but in the wild the zoeas are then washed downstream into salt marshes/brackish water where they develop. If they don't make it to salty water in the first few days they die. Once they've matured, they move back upstream, though they can remain in brackish water for quite some time after converting to their adult form, perhaps for their entire lives (?).

With male and female amanos you should find one berried occasionally. The females are much larger than the males, so if you've only got one size of shrimp, you've probably got a single sex tank.

[JoeD323]

Originally Posted by jasonpatterson

There is also substantial sexual dimorphism in amanos, so different sized shrimp in the population often means large females and small males mixed.

I definitely think this is the most likely scenario. In the story that originally prompted me to start this thread, the man stated that his shrimp were in there for some years. This would lead me to believe that they were the same size when he got them and matured into large females and smaller males, but at such a slow rate that noticing the growth is unlikely. Now, years later, you look at them and notice that there are "smaller" shrimp in the tank but in reality they are all the same shrimp, just some got bigger than others.


Makes sense to me.


Joe