Astrea snails still alive after eating massive amounts of dinoflagellates

[Koleswrath]

Just a curiosity post, but maybe there are some folks who have had similar experiences. 

My Astrea snails are still alive and trucking two months after consuming alarming amounts of Ostreopsis Dinoflagellates. These are considered one of the most toxic species we commonly encounter in our tanks so I was expecting the snails to die at some point shortly after seeing this.

Since it’s been at least two months since first observing the snails eat the Dinos I think it’s safe to say they are going to be fine and were largely unaffected.

Any thoughts/theories? Maybe a species of Ostreo that isn’t as toxic as others?

 

[mcarroll]

On 4/16/2023 at 10:42 AM, Koleswrath said:

Any thoughts/theories? Maybe a species of Ostreo that isn’t as toxic as others?

A few....

1. "Toxic dino's" may not always be toxic.  If overall conditions are good, they seem to be quite anonymous epiphytes that apparently blend in more or less harmoniously with the rest of the ecosystem's micro-flora and -fauna.
2. Folks are affected by shellfish poisoning due to eating critters that were living with LOADS of toxin.   So larger critters (ie food items to us) can live with toxic dino's as a food source.  So even when dino's are toxic, eating them isn't necessarily lethal.
3. I've read that most of the toxins in a dino bloom aren't in the dino cells – it's actually in the mucus they create and live in for protection from flow, light, etc.  (Usually their mucus blobs are all that's visible to our naked eyes.)  In this stage (blooming) they are a MUCH bigger problem....things around them, including snails, usually start dying.
4. Further complicating things, if your Astreas were getting a healthy diet high in proteins (eg microfauna among the algae they eat) the toxins in their diet can be processed by them (and pooped out) without as much impact...maybe no impact.  (This is apparently how lots of critters generally tolerate "anti-nutrients" in plants.)   On the flip side, if dino's is all there is to eat (ie not enough green algae), then the snail is probably going "belly up."   Having (eg) green algae blooming WHILE you have a dino bloom is almost a paradox.  

So this is why snails living with (and eating) dino's don't have a good prognosis in general, but it's also not necessarily a "death sentence".