What Are These Black Spots?

HI Everyone,

I just started a five-gallon, freshwater, planted nano tank, and I've noticed that since I added the plants yesterday, odd blackish growths have appeared on some of them. I bought the plants prepackaged at Petco, and I didn't notice the black spots on them when I inspected them before planting them in the tank. I'm cycling, so there are currently no fish or invertebrates in the tank.

Does anyone have any information about what these growths are, whether they are harmful to either the plants or fish, and what do about them? I'm new to planted tanks, but I do have Seachem root tabs in the gravel, and I've added Seachem Flourish, Flourish Excel, and Iron Supplements to the water.

The affected plants are both Asian Waterferns, according to Petco at least. The Java Fern and the Anubias seem fine. I'd appreciate any help you can offer. Thanks for reading!

 

They look like snails to me. Are they moving around?

 

Nope. I've been watching them for about 24 hours and there's been no discernible movement or growth even. Up close, they look either like small hard nodules or black strings. No shells or snail-like bodies really.

(Also: I bought these plants last week in plastic packaging at Petco, not out of a tank; wouldn't snails have died after an extended period of time in a dry plastic case?)

 

Snails are pretty tough but I don't know it they would survive that. It is really hard to tell what they are from the photos but snails were the only thing that came to mind. maybe dead snails ?

 

I believe they are new baby plants beginning to form on the leaves. eventually they will grow long brown roots and leaves. when they get big enough you can pinch them off and plant them (or rather, attach them to something -- you should not bury the rhizome of this plant).

the leaves may be making baby plants because the plant was grown in its emersed form and is adjusting to being submersed under water. java ferns and asian ferns do that.

 

Snails are pretty tough but I don't know it they would survive that. It is really hard to tell what they are from the photos but snails were the only thing that came to mind. maybe dead snails ?

Thanks for your help! If they are snails, I'd think they'd have to be dead by now--even if they survived desiccation, the plants have been in an un-cycled tank for a couple of days now where I've been building up ammonia.

I believe they are new baby plants beginning to form on the leaves. eventually they will grow long brown roots and leaves. when they get big enough you can pinch them off and plant them (or rather, attach them to something -- you should not bury the rhizome of this plant).

the leaves may be making baby plants because the plant was grown in its emersed form and is adjusting to being submersed under water. java ferns and asian ferns do that.

Hmm..I didn't know ferns did this; this explanation seems more likely to me than the snail theory, since I first noticed the black growths after adding the Seachem fertilizers.

I currently have my ferns secured under maybe .5-1 of regular aquarium gravel. I figured that this would be fine since there are root tabs in the gravel and fertilizers in the water column. And they don't seem to be wilting or otherwise reacting negatively. But given your advice, should I dig out the rhizomes and try to attach them to a rock or piece of driftwood instead?

 

You can bury the roots, but leave the rhizomes exposed or they will rot. Overall does better attached to something rather then planted. Species is bolbitis heteroclita. And yes, midnais correct, those are plantlets forming. Times of stress (new environment, etc) cause them to throw out plantlets like crazy

 

Thanks for your help! If they are snails, I'd think they'd have to be dead by now--even if they survived desiccation, the plants have been in an un-cycled tank for a couple of days now where I've been building up ammonia.

You would be surprised as to all that snails, specially the pest snails, can survive.

I like the new plant theory. Like you I didn't know little plants grew like this. I do know that plants under stress do try to reproduce so these being plantlets makes sense to me. Deprive your morning glory of water and they bloom like crazy. Give them all the water they need and they just grow big healthy leaves.

 

Thanks a lot for your responses! It's a relief to know that these growths are part of the ferns themselves; I had been worried that they might overtake the (rather expensive) plants.

As a side note, I'm new to planted aquariums, so I'm a bit confused as to the difference between roots and rhizomes--can someone clarify briefly? (A google query just left me more confused.) I probably did bury them unknowingly with the roots, so I'd like to correct before there's too much damage.

 

Thanks a lot for your responses! It's a relief to know that these growths are part of the ferns themselves; I had been worried that they might overtake the (rather expensive) plants.

As a side note, I'm new to planted aquariums, so I'm a bit confused as to the difference between roots and rhizomes--can someone clarify briefly? (A google query just left me more confused.) I probably did bury them unknowingly with the roots, so I'd like to correct before there's too much damage.

I've never had this plant but I believe the rhizome is situated right where the leaves start coming out of the root ball. If I understand correctly you don't want to bury anything but the roots if you are planting it. You could just tie it to a rock or something similar and just let the roots go where they choose to go. That would keep from suffocating the plant.

 

I've never had this plant but I believe the rhizome is situated right between where the leaves start coming out of the root ball. If I understand correctly you don't want to bury anything but the roots if you are planting it. You could just tie it to a rock or something similar and just let the roots go where they choose to go. That would keep from suffocating the plant.

Okay, thanks for the advice! I just ordered some biodegradable thread online--I'm hoping I can use that to tie it some driftwood or rocks in the tank.

 

I think that's the best plan Like mentioned, they do better when they are attached to something. The bolbitis I threw into my 90g at the back just rooted into the gravel itself. Then it booms like crazy. It does best when there is enough circulation around the rhizome, so sitting on top or attached to hardscape is best ime.