Snail Maximum?

[berkdog]

Is there a recommended limit on the number of snails to put in a tank? In my 75G FOWLR tank, I have about 50-100 (I forget), but found sweet a deal for several hundred more online (mostly florida ceriths, nerites and nassarius vibex).

Anything to be cautioned about regarding so many snails? I've read fresh water snails reproduce like crazy, but I read that salt water snails don't get that far in the home aquarium (usually eaten as eggs by the fish). Thanks!

[Ninong]

Nassarius vibex eat carrion and meaty detritus and they require a sand bed to burrow in. If you do not have enough carrion and meaty detritus, you will have to supplement their diet with sinking pellets designed for carnivores.

Ceriths and nerites are grazers. Ceriths usually graze the sand bed near the glass but they can also be found climbing the glass in search of film algae. Nerites are nocturnal and they spend their days at the top of the tank next to the water's surface, hiding under the bracing. At night they cruise the live rock. Their white eggs look like sesame seeds on the live rock. Ceriths lay their eggs in spiral strands on the glass walls of the tank at night.

Obviously you can't keep more snails that you can support with appropriate food sources. Also, none of those snails will reproduce in home aquariums.

[berkdog]

Thanks! So what's a recommended number? Or estimated range?

[Ninong]

There is no estimated number or range. It depends on the individual situation.

[leebca]

As Ninong wrote, the number is dependant upon your needs. I like to start off low and add more as I go along until I see everything is being kept under control. You might want to begin with 2/gallon of the herbivores and those that eat diatoms, then adjust from there. If they are really small, then you can double that to 4/gallon.

Keep in mind that if your aquarium will be running near 80F then the snails you need are tropical snails. If the snails you acquire are from cooler waters, they can 'cook' in a tropical aquarium -- dying off in a few months.

[berkdog]

thanks for the replies!

just FYI about the reproduction of nerite snails... I bought a lot of 100 or so, and they quickly laid eggs all over the tank. A couple of weeks later, I have found 3 baby snails on the walls!!!! Perhaps I need to take pictures, but they look like baby nerite snails!!

the only problem I see with nerite snails is that they crawl to the top of the tank at night. and that's fine, except when they're on an intake valve and end up crawling all the way up the valve and onto the floor! I find 2-3 do that every morning!.... I need to figure a way to solve this problem.

They came from Florida (from reefcleaners), and are supposedly good for tropical tanks. They seem happy and have already cleaned the entire tank better than I do when I make water changes and clean!

[Ninong]

just FYI about the reproduction of nerite snails... I bought a lot of 100 or so, and they quickly laid eggs all over the tank. A couple of weeks later, I have found 3 baby snails on the walls!!!! Perhaps I need to take pictures, but they look like baby nerite snails!!

I suspect that you may have too many nerite snails for a 75-gallon aquarium. Yes, maybe you should take some close-up pictures of your "baby snails." That would be interesting. As far as I know, there have been no reports of nerite snails reproducing in home aquariums. Perhaps it is because their planktonic larval period is too long and the larvae are likely to be destroyed before they have a chance to mature. Also, I don't think we have any clue what the nutrition requirements are during the larval stage.

BTW, have you witnessed any of your nerite snails engaging in sex? I never did catch any of my nerites in the act but maybe they do it at night?

the only problem I see with nerite snails is that they crawl to the top of the tank at night. and that's fine, except when they're on an intake valve and end up crawling all the way up the valve and onto the floor! I find 2-3 do that every morning!.... I need to figure a way to solve this problem.

My aquarium had 2" euro-style perimeter Starphire glass bracing that prevented the nerites from leaving the tank at night. They just gathered at the water line half-exposed. I think they do this because they are naturally intertidal.

What I found annoying about nerites was that I had to run my hand around the top edge of the glass to knock off all the nerites before I could clean the glass. I don't think I bought more than a dozen of them for my 120-gallon aquarium and I'm glad that I didn't get more. They were okay but they weren't my favorite snails.

They came from Florida (from reefcleaners), and are supposedly good for tropical tanks. They seem happy and have already cleaned the entire tank better than I do when I make water changes and clean!

The snails that we get from Florida and Baja California are all temperate but most of them perform quite well in reef aquariums, although they don't live as long as they would in the wild. Nassarius snails, for example, have a natural lifespan of up to 50 years in the wild but they never last more than a few years in our aquariums because we don't provide them with an ideal environment.

[berkdog]

I will try to take some pictures tonight

Honestly, I don't know what snail sex looks like, but I assume they are engaging in sex when their flesh touches and they crowd up in groups. I don't want to use vulgar words, but let me add that my friends say they look like they are doing it in groups.

[Ninong]

I will try to take some pictures tonight

Honestly, I don't know what snail sex looks like, but I assume they are engaging in sex when their flesh touches and they crowd up in groups. I don't want to use vulgar words, but let me add that my friends say they look like they are doing it in groups.

I don't know if nerites do it in groups or not because I don't think I ever saw them doing it. I know that nerites have separate males and females and that the males have a penis that they use to impregnate the females. With my eyesight, I'm afraid there is no way that I would be able to confirm that for you through personal observation.

[berkdog]

I'm attaching photos. It appears to be a baby nerite (from it's bottom). I also have a picture of the huge groupings of eggs (no baby snails in that picture), and one of the baby snails from the top side.

[Ninong]

I'm afraid that the pictures of the "baby nerites" are not sharp enough for me to make out much of anything. How many of these "baby nerites" do you see? What size would you estimate that the "baby nerites" are now? Can you describe anything about their appearance? What does the shell color look like? Do you see any evidence of any sort of pattern or striping on the shells? Are there any other identifying characteristics that you could describe?

Have you tried to remove one of them to examine it more carefully under a magnifying lens? If you do remove, one what do you see when looking at the aperture?

[berkdog]

I saw about 4, maybe 5, of the "baby nerite" snails out of the hundreds and hundreds of eggs (the live rock is all covered with snail eggs too). The baby snail base looks like a nerite snail, but smaller. The top/shell side has a point on top (it's not completely smooth/round, but has a tip like a cone). They are about the same size as the eggs, maybe a tiny bit bigger, and not as thin. The shells I can see look dirty, but I can see a thin white line going around one of the shells (I can't see all of the shells because of the angle of the glass and the top of my tank).

What do you think they are, if not baby nerite snails? I didn't take any outside of the tank. Do you recommend I do that? I tried to take the photos on macro setting, and I uploaded the full sized pictures, so you should be able to enlarge them and zoom. If you're really interested, I could put one in a plastic bag and mail it to you, but it'd probably die on the way.

[Ninong]

If you have any sort of a clear glass saucer or coaster that you could remove one of them from the tank long enough to examine it and maybe take a better picture of it, that might help narrow down the possibilities. You could even have a small amount of tankwater in the saucer or coaster so that it might move around. The least likely possibility would be that they actually are baby nerites.

[berkdog]

If you have any sort of a clear glass saucer or coaster that you could remove one of them from the tank long enough to examine it and maybe take a better picture of it, that might help narrow down the possibilities. You could even have a small amount of tankwater in the saucer or coaster so that it might move around. The least likely possibility would be that they actually are baby nerites.

Ok, I took one out. Taking it out, the snail shell was hard, but I think I could have pressed it down with my finger and cracked it. It didn't quickly stick to the side when I put it back in, and it landed on the sand on the bottom of the tank. I hope it survives!

Any better idea of what it is? In the new pictures, I posted one of the large nerites and 4 of the baby snails (same baby snail, but 4 pictures--2 from top, 2 from bottom).

[berkdog]

Also, I believe I saw some adult nerites mating. When they are climbing on top of each other, there is an area where they are touching, usually where one is invading the other. Anyway, I might be wrong. I'm not too interested in snail sex BTW, so hope you don't want pictures of that too

[Ninong]

I don't know if it's because of my lousy eyesight or if the pictures are out of focus or what but I can't see much of anything in pics #2 and #3. Also, I should have asked you to take a picture of the aperture with the snail retracted.

Based on what I have seen so far, I'm still leaning in the same direction I have been since you first announced your discovery. However, I really can't make out anything at all in pics #2 and #3. Again, this could be my eyesight. That's why I prefer relying on verbal descriptions. So far your verbal descriptions fit what I think it is but pics #2 and #3 are throwing me off because they don't look the way I expect them to look. The other pics are all fine and look the way I expected them to look.

You should be able to remove one of these guys and look at it with a simply 2x magnifying glass. At least that's what I need to see anything. Looking at the shell, does it look like a miniature turbo snail or does it look like a nerite snail or something else? In other words, does it look like a tiny turbinid?

When the snail retracts into the shell, do you see an operculum closing off the aperture? Is there a noticeable pit in this operculum?

Anyway, an examination under any sort of magnifying lens should allow you to immediately determine whether it looks like a miniature nerite or not. My money's on not. ;;

[Ninong]

I'm not too interested in snail sex BTW, so hope you don't want pictures of that too

Yes, absolutely! We always take pics of marine animals caught in the act and then post them online for everybody to see. We do this for fish mating rituals all the time, why wouldn't we do it for snails?

I can describe the foreplay engaged in by Scott's fairy wrasses as part of their mating ritual in detail but a brief video clip would be much more informative. Unfortunately, I didn't have a suitable video cam at the time. I know I posted a link to a nice YouTube clip of a pair of Centropyge angelfish spawning a few months ago. I always post stuff like that when I come across it.

[berkdog]

I don't know if it's because of my lousy eyesight or if the pictures are out of focus or what but I can't see much of anything in pics #2 and #3. Also, I should have asked you to take a picture of the aperture with the snail retracted.

Based on what I have seen so far, I'm still leaning in the same direction I have been since you first announced your discovery. However, I really can't make out anything at all in pics #2 and #3. Again, this could be my eyesight. That's why I prefer relying on verbal descriptions. So far your verbal descriptions fit what I think it is but pics #2 and #3 are throwing me off because they don't look the way I expect them to look. The other pics are all fine and look the way I expected them to look.

You should be able to remove one of these guys and look at it with a simply 2x magnifying glass. At least that's what I need to see anything. Looking at the shell, does it look like a miniature turbo snail or does it look like a nerite snail or something else? In other words, does it look like a tiny turbinid?

When the snail retracts into the shell, do you see an operculum closing off the aperture? Is there a noticeable pit in this operculum?

Anyway, an examination under any sort of magnifying lens should allow you to immediately determine whether it looks like a miniature nerite or not. My money's on not. ;;

I can't get any better pictures with my camera, but the shell shape is like a ice cream sugar cone (there's a sharp point at the end). The snail can't retract much into it's shell because it just pulls itself in, but it's still reachable. I'm not sure what turbinid means. Do you think these might be baby turbo snails? That's possible since they have a cone shape too? The nerites are round and smooth on top, and these babies have a defined point. And sorry, I don't know what an operculum is.

So is your guess that it's a baby turbo snail? I guess that's possible, but I don't have any turbo snails in the refugium where the baby snails are, but if the eggs are tiny and can pass through a filter, then that's more believable.

[berkdog]

Yes, absolutely! We always take pics of marine animals caught in the act and then post them online for everybody to see. We do this for fish mating rituals all the time, why wouldn't we do it for snails?

I can describe the foreplay engaged in by Scott's fairy wrasses as part of their mating ritual in detail but a brief video clip would be much more informative. Unfortunately, I didn't have a suitable video cam at the time. I know I posted a link to a nice YouTube clip of a pair of Centropyge angelfish spawning a few months ago. I always post stuff like that when I come across it.

Eeeh, I'll keep that in mind if I find anything in the tank "in the act" with my camera already out. =)

[Ninong]

I can't get any better pictures with my camera, but the shell shape is like a ice cream sugar cone (there's a sharp point at the end).

That's not what I was expecting, which is why I said I couldn't figure out what I was looking at in pics #2 and #3.

I'm not sure what turbinid means.

A turbinid is any member of the family Turbinidae.

Do you think these might be baby turbo snails?

Not anymore. I didn't think they were baby turbo snails, I thought they might be turbinids. That covers a lot of territory but I was thinking possibly Collonista sp. I asked you if they looked like baby turbo snails because I thought that would give you an idea of the shell shape I was looking for.

That's possible since they have a cone shape too?

I don't follow you here? Turbo snails do not have a cone shape. As the very name implies, their shells are shaped like a turban. That's where they get their name. Both the name of the family (Turbinidae) and the name of one of the genera in that family (Turbo) are derived from the word turban.

Perhaps you're confused because so many online vendors invent ficticious names to market their snails? As I said previously, I have seen Astraea sp. snails sold as Turbo snails and as Trochus snails. Astraea snails are neither. They are turbinids because they're members of the Family Turbinidae, the same family as Turbo snails but they are not turbo snails. Some online vendors like to call just about everything turbo snails. We run into a similar situation with Ilyanassa obsoleta. It's a member of the Family Nassariidae but it is not a Nassarius snail. Nassarius is the name of one of the genera in the Family Nassariidae. Nassarius vibex is the snail that we are looking to buy but some irresponsible vendors will ship I. obsoleta (a very undesirable species) and insist that it too is a Nassarius snail. It is not. It's a nassariid but it is not a Nassarius snail.

Some vendors have a habit of shipping Astraea sp. snails that they advertised as "turbo snails" or even "trochus snails." Most of their customers don't even know the difference. They're always surprised when they post pics of their new "trochus snails" (or "turbo snails") and someone tells them they really have Astraea snails instead.

And sorry, I don't know what an operculum is.

The operculum is a corneous or calcareous structure in most marine gastropods (snails) that have shells and gills. The operculum is attached to the foot of the gastropod and the two primary purposes are to help prevent the snail from drying out (in the case of intertidal snails) and to help protect against predation. The turbo is an excellent example of a snail with a large operculum that helps prevent predation. Think of it as a trap door that the snail closes behind itself when it retracts.

Operculum is a Latin word meaning lid or cover.

So is your guess that it's a baby turbo snail?

No, I never did think it was a turbo snail. I thought it might be a turbinid but not a member of the genus Turbo. I never did think it was a baby snail either. I thought it might be an adult turbinid, possibly a member of the genus Collonista.

...but if the eggs are tiny and can pass through a filter, then that's more believable.

If you ever do have Collonista sp. snails, you may discover them all over the place. I have no clue exactly what their mode of reproduction is. As you may know, some snails hatch as larvae that enter the plankton for a period ranging from days to weeks. The larvae may or may not be feeding during that period. Other snails have direct development. They exit the egg capsule as miniature snails. I have had hundreds of Collonista snails but they're nocturnal, so you don't get to see much of them during the day. In fact, you don't see them during the day unless you're cleaning out your sump or breaking down your pump to figure out why it has suddenly slowed down a lot.

Collonista snails are prolific breeders in a reef aquarium. Extremely prolific. They're grazers. They appear to graze on algal films, diatoms and maybe some detritus. I'm not sure. All I know is that if you turn your lights on three or four hours after all lights in the room went off, you will see hundreds of them all over the place, including all over the glass. They are so proficient that they will starve out other species of snails that your paid good money for. They population density swings up and down depending on available stuff to eat. I think.

P.S. -- Check out this article by Dr. Ron Shimek. In it he has drawings of the typical shell shapes for turbo, trochus and astraea snails. He also has photos of Collonista snails. I was thinking that maybe you had Collonista snails but their shell is not shaped like an ice-cream cone.