Neritidae

Group of Clithon corona

These beautiful snails hail from the Neritidae family.  They are close relatives to the common Olive Nerites, Zebra nerites, red spotted and so on.  These horned nerites, however, are my favorite of them all.  Their yellow and black stripes appeal to me and who wouldn't love those horns?  A horned snail is definitely a unique spectacle to most.  

Aside from being aesthetically pleasing however, their function is much greater.  They are #1 on cleaning glass algae.  

All the snails available in the freshwater hobby under the name "Nerite" are excellent glass algae scrapers.  If you ever get tired of green spot algae, brown spot algae or anything that requires you to scrape, these snails will do the job for you.  

I have kept these before a few years ago, when I was in the hobby.  I had a 10 gallon tank with all four walls covered in thick brown glass algae.  I threw in a few (2-3) olive nerites and within a week, it was clean and clear.  I never had to stick my hand in there to scrub the glass.  

Clithon corona will do the same and also give your tank a nice looking specimen.  I would recommend at least 1 per 10 gallons.  I added 4 in my 20 gallon tank because I will be moving 2 into the CBS tank in the near future, when it is done cycling.  

To record this process, I have taken photos of my tank currently.  

As you can see, the walls are quite filthy.  My previous blog posts of shrimp even show the brown spot algae on my photos.  It clouds my images immensely.  

Today is day #1 of adding the snails (January 15, 2012).

When taking nerites into consideration as a co-inhabitant in your shrimp tank, you should understand that these guys will NOT breed in freshwater.  So if your tanks are snail free like mine and you want to keep it that way, these guys are perfect for you.  (Although technically nerites are snails...)

Furthermore, nerites, like all snails, ideally require higher ph water to maintain good shell growth.  Because we keep CRS in lower ph, do expect shell degradation overtime.  Shell thinning and possibly getting "uglier" over a period of time will be normal and should be expected.  It's an unfortunate fate for these guys.  

Average lifespan seems to be approximately 1.5-2+ years.  This has been reported by local aquarists that I have spoken to and my own personal experience as well.

FAQ

Q:  Can nerites breed in freshwater?

A:  No, but they do lay eggs that will never hatch.  Eggs can be spotted as white dots in your tank.  They are often laid on driftwood or any hard surfaces.  Some argue that in exchange for no algae, you end up with eggs all over the place.  I never had this problem though as the eggs usually disappear overtime.  They will only lay an abundance of eggs if your tank is literally infested with too much algae.  

I will update how the tank is doing in the next couple days.

More photos to below.