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Having found this thread in the Recovery room, I thought it appropriate to post a repeat post about cyanobacteria, as a 'heads up' about these organisms.

Numerous species of cyanobacteria produce toxins. Quite a few of these toxins are dangerous, indeed lethal to humans, in some cases in doses as low as 1 microgram per Kg of body weight. Among the toxins produced by cyanobacteria are:

Anatoxins (Anabaena flos-aquae from Canada)
Cylindrospermopsin (Cylindrospermopsis raciborskii found in Queensland drinking water)
Microcystins (Various members of the cyanobacteria Genera Anabaena, Nodularia, Nostoc, Oscillatoria and Microcystis)
Nodularins (Nodularia spumigena in brackish waters)
Saxitoxins (Anabaena circinalis and a range of marine dinoflagellates)

Of these, saxitoxins are the most lethal, and sometimes migrate up the food chain via shellfish which are consumed by humans. ALL of these toxins should be considered highly dangerous, however!

The BIG problem here is this - how do you know if you have one of the generating cyanobacteria species in your aquarium? Chances are you don't - unless the toxins start killing your fishes!

Identifying these organisms to species level generally requires expert assistance. If you have recently witnessed a range of fish fatalities of otherwise unknown cause, in an aquarium that has a bad cyanobacterium problem, it would be worth your while submitting specimens of the cyanobacteria for analysis to an appropriate lab to see if cyanotoxins are an issue.

Here are some page references for the various toxins:

Anatoxins
Cylindrospermopsin
Microcystins and nodularins
Saxitoxins

By the way, I only found out about this completely by accident when researching a totally different topic. Heads up, everyone ...


Panda Catfish fan and keeper/breeder since Christmas 2002

Hi,
Here is another interesting site about this critter:
http://www.ucmp.berkeley.edu/bacteria/cyanofr.html

It's been around, nearly forever!

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Didn't know it was THAT toxic. A few months ago I was cleaning some BGA out of my old shellie tank, picking it with my fingers and after merely wiping my hands with a dry towel I proceeded to rub my eyes. Bad move. I had a nasty eye infection for 4 days, my right eye was swollen nearly completely shut for the first day. I now make a point to wash my hands thoroughly after touching any type of algae. Good posting Cali

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Back in the saddle!