Found a new creature in my tank. What is that?

[BaRanchik]

Those appeared about a week ago. They seem like some kind of a slug if you look at them from above, but l caught one eating algae from the glass so I got a picture of it. Looks like a baby snail, it moves and eats like a snail, but its shell is clam-like? What is this thing?

Snails I keep/have seen in my tank before are malaysian trumpet snails and pond snails.

P.S. sorry for the bad GIF quality, that's the best I could make to upload here.

 

[Nirvanaquatics]

Freshwater limpet! It's a friend, don't worry 😊

[BaRanchik]

On 7/4/2021 at 6:02 PM, Nirvanaquatics said:

Freshwater limpet! It's a friend, don't worry 😊

That's cool! Do you have any idea how big they grow? I don't mind having some extra workers for my cleaning crew.

[Nirvanaquatics]

On 7/4/2021 at 10:17 AM, BaRanchik said:

That's cool! Do you have any idea how big they grow? I don't mind having some extra workers for my cleaning crew.

Like a couple inches long and mostly flat. I don't know a ton about them, but I've seen them before in other people's tanks and they are known to be great algae eaters 😊

[Griznatch]

Those are awesome, were they hitch hikers you think?

[BaRanchik]

On 7/4/2021 at 6:29 PM, Griznatch said:

Those are awesome, were they hitch hikers you think?

I believe so. Last time I got new plants was about 3 weeks ago, so they could have been on those.

[GameCzar]

On 7/4/2021 at 10:02 AM, Nirvanaquatics said:

Freshwater limpet! It's a friend, don't worry 😊

 

[Odd Duck]

On 7/4/2021 at 10:20 AM, Nirvanaquatics said:

Like a couple inches long and mostly flat. I don't know a ton about them, but I've seen them before in other people's tanks and they are known to be great algae eaters 😊

A couple inches?  I’ve never seen them get over a couple millimeters!

[NanoNano]

I've got these lovable little buggers in a bunch of my tanks.  Same experience as @Odd Duck- mine maybe at most reach the size of about a half a grain of dried Jasmine rice.  Great janitorial staff and excellent at eating detritus and tough green spot/dust algae (though each limpet eats only a tiny bit, so you need a horde of them to be effective).

 My experience has been that when you see them moving around comfortably in the light, a population explosion is already in progress.  The baby boom generally last 7-10 days, after which their numbers will normalize and they will go back to hiding in the substrate and the underside of plant leaves when there's light.  The shells are strong,  but very thin, so a) they dissolve in water in a day or less after one of them dies b) if you get completely overrun by them,  you *can* apply pressure to the top of their shells while they are on a hard surface and cull them.  They're a bit unsightly,  but the times I've had a tank biome go wonky,  they've rallied and been a big part of getting things back right.  I'd rather have them in my tanks than not.