Does anyone use shrimp anymore for algae control?

[Koan]

I thought ghost shrimp carried disease

There's a lot of chatter handed around The Internets that ghost shrimp carry and transmit White Spot, or "ich", to fish.

Well, yes and no.

The Ichthyophthirius multifiliis ciliate is an obligate fish parasite, meaning it can only infect and reproduce in fish.

That being said, the multi-step life cycle of this protozoan does include a free floating and physically sticky "tomont" stage. This can be carried on any fomite, and pass infection to a new tank. It can stick onto the outside of snails, or shrimp, or fish nets and aquascaping tools, and create an outbreak in fish. It can even be carried in aerosolized splash spray in a fish room, and transmitted to new tanks that way.

So nothing specific to ghost shrimp.

This story probably originated in that they have long been sold in fish stores as feeder shrimp, and could act as a fomite for this infective stage to a home tank, if there was an outbreak there in shared tanks or shared water.

What could have complicated the story is there is actually a viral shrimp disease called White Spot, that is a big deal in salt water shrimp / prawn farming. So far, it is not among the diseases of freshwater ornamental shrimps

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[Kwyet]

Thanks for the info! I did hear/read about in connection to feeder shrimp, so that’s probably it.

 

[Koan]

The good news is, the sticky cyst stage only lasts about 24 hours before it "hatches out" the free swimming infective stage. Then that stage is viable for a maximum another 48 hours. If the free swimming stage doesn't find a fish in that time, it just dies.

So fomite transmission via a shrimp, or a snail or a fish net, is only for a period of about 72 hours.

If you get feeder shrimp from a fish store, just quarantine them for 3 days before putting them in with fish and you will be safe from "ich"

This is different from infected fish, which can remain contagious for up to 30 days. Once the parasite is happily living in its host, it takes longer to wait it out.

 

[BranchScape]

So time to buy some, put them in clean water for a few days. Then I can introduce and party with 25 shrimp for a few dollars.