Re: NANFA-L-- Tiny limpets(?)-in-water line / snails & crayfish

dlmcneely-in-lunet.edu
Thu, 01 Dec 2005 07:36:45 -0600

Pennak's _Freshwater Invertebrates of the United States_ lists limpets
and provides identification keys and descriptions. One genus common in
coolwater streams is _Ferisia_, which is only about 3 mm long in the
specimens I have seen from Oklahoma and Arkansas. I can't imagine any
harm that these beasties would do in your tank.

Crayfish will eat both snails and the plants you mention.

Dave

David L. McNeely, Ph.D., Professor of Biology
Langston University; P.O. Box 1500
Langston, OK 73050; email: dlmcneely-in-lunet.edu
telephone: (405) 466-6025; fax: 405) 466-3307
home page http://www.lunet.edu/mcneely/index.htm

"Where are we going?" "I don't know, are we there yet?"

----- Original Message -----
From: Jase Roberts <nanfa_list-in-jaseroberts.net>
Date: Wednesday, November 30, 2005 11:28 pm
Subject: NANFA-L-- Tiny limpets(?)-in-water line / snails & crayfish
> Hi,
>
> In one of my native tanks (north-central Vermont) I started seeing
> tiny snail-like critters right about-in-the water line. These
> guys are really small -- from less than 1mm long to maybe 2mm long
> now (definitely growing somewhat). I can't make out too many
> details with a 10x hand lens, but I can see that they've got snail-
> like mouths and probably antennae. What I can see of the shells
> looks a lot more like a limpet than a normal snail. They look to
> be roughly conical and fit tightly to the sides (I can push the
> critters around with a toothpick and they stay suctioned to the
> glass). The top set of pics-in-the bottom of
> http://members.aol.com/mkohl2/Fwlimpets.html looks about right,
> although mine are way smaller. There are probably 15 or so
> visible in my 10 gallon now, all right-in-the water line.
>
> Do folks have experience with freshwater limpets? Are they common
> thing to have living in native aquaria? Any chance this is
> actually a life stage of a more conventional snail (I did have
> some in snails in this tank earlier)? I'm surprised that there
> doesn't seem to be anything in the NANFA e-mail archive mentioning
> limpets.
> Second, I'm wondering about folks' experiences with crayfish/snail
> interactions. I had 6 or so smallish snails in my 30 gallon tank
> that disappeared within a week (only one large ram's horn snail
> remains). At the time I blamed my pumpkinseed, but now I wonder
> if the crayfish I had was actually the guilty party? I see some
> references to crayfish eating snails elsewhere on the Internet.
> Is it possible to have snails and crayfish co-exist in a tank, or
> will crayfish eventually wipe the snails out? I feel like I need
> some snails to control algae growth.
>
> I also suspect my crayfish to be the culprit in cutting free the
> Coontail/Hornwort (Ceratophyllum) plants I have tied to rocks-in-
> the bottom. The plants are doing great in my 10 gallon tank
> without crayfish, but most were floating free and stuck to the
> filter within a week or two in the 30 gallon where the crayfish
> lives. Again, do other folks have experience with this?
> Solutions to keep the plants in place? Sorry, no idea on the
> species of the crayfish.
>
> Thanks,
> Jase
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