Tropical Fish Forum
Tropical Fish Keeping => Invertebrates - Shrimps and Snails => Topic started by: Skittler on April 07, 2016, 12:00:33 PM
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Sue's Nerite pictures in Gallery Showcase show quite a range of different nerites. Also, quite a few eggs. I currently have 4 Zebra Nerites in my 125l, and a steadily increasing number of eggs. Some of the eggs are in places that I didn't think a large Nerite could reach, e.g. the top section of a vallis leaf.
Does anyone know if different species of Nerite can interbreed? Because, if not, then the solution to the "egg" problem might just be to only have one of a few different species. Not only that, but they would add more colours & variety to the tank.
Skittler
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Hi Skittler,
As far as I'm aware, female nerites will lay eggs regardless of whether there are males in the tank or not. I have three different varieties of nerite in my tank and eggs everywhere! I'm pretty sure I know which one is the culprit, as she is the only snail in my tank not covered in eggs!
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Since nerites need a male and female to produce eggs, I assume they can only breed with the another snail of the same species. The different patterned ones should be different species.
I've only ever had nerite eggs when there have been at least 2 of the same colour/pattern. With the 6 in the 180 litre at the moment, I have no new eggs, and they can't all be males.
I did have 2 of the grey ones (type #1 in the snail thread) when I first got them and one of them laid eggs everywhere, including on the tank walls. None of the previous snail breeding resulted in eggs there! Since I separated the grey ones there have been no more eggs.
I've had a red onion snail (#5) in with what looks like a different patterned red onion (#2) but they are different enough to be separate species and there have been no eggs.
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Thanks both.
Cod: Do you only have one of each type? If so, could it be that one was fertilised in the LFS, or earlier, where there would be many males and females?
Before posting I did have a good google, and (inevitably) found differences of opinion about whether they were hermaphroditic or not. However Sue, your experience suggests strongly that they are not, and that the way to go to avoid eggs might well be to buy one each of a number of different types of Nerite.
Thanks again both,
Skittler
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Just to be clear :
hermaphroditic = each individual has the organs of both sexes within it. They still have to mate to produce viable eggs.
not to be confused with :
parthenogenetic = able to reproduce without mating (e.g. Indian stick insects)
Many snails are hermaphroditic, don't know if any are parthenogenetic. The eggs laid by unmated snail may be sterile.
The reliable information is that nerites are neither.
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Thats good to know, the eggs are very unslightly, I'll have to have a nerite juggle and split my same species up.
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Depending where you read, malaysian trumpet snails are reputed to be parthenogenetic.
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They breed fast, I know that much but to be honest I don't mind, it just means all the more of them doing a good job.
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MTS are known to be viviparous, giving birth to live young as opposed to laying eggs. I wonder if some people are confusing this with parthenogenesis.
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MTS are known to be viviparous,
:o blimey I didnt know that
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I have three nerites: a black olive, an onion and a zebra. I have eggs everywhere. Therefore I don't think splitting the varieties will do anything to stop them laying eggs. You just need to be lucky and only have boy nerites!
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Interesting. I have 6 nerites in my 180 litre at the moment, and I have no eggs being laid at the moment, the ones on my decor are old eggs. I can't believe they are all males ???
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My morpani wood looks like its been dipped in sesame seeds :( Not a good look
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Same here Fiona.
Sue - I think they can take a while to acclimatise I didn;t have any eggs for months!
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I've had 2 of the snails for over 4 years (zebra and red onion), one for just over 2 years (bee nerite, actually a Clithorn species which shouldn't breed as that's the only Clithorn), and 3 for just over 1 year (red and black one which isn't quite a red onion, black with very thin brown zigzag stripes) and grey (which I think might be a Clypeolum and shouldn't breed with any of the others). They should be settled by now!
I do have another grey one which used to be in the 180 litre but the two of them bred so I separated them and no more eggs since then.
So of the 6 snails in the 180, I'm pretty sure that 2 of them are singles of two different species. That leaves the other four as possibly different patterns of the same species.
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Thanks Everyone,
Cod: Your post is clear to me. If you have Nerites, there is a good chance you will have eggs. Perhaps, even with the absence of a male, a female will deposit (infertile) eggs anyway. We aren't going to know as fertile ones will not hatch in our tanks.
Never mind, it seemed such a good idea at the time!
Thanks again all for some good information,
Skittler
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My daughter's boyfriend had one Nerite snail in his tank and has eggs covering his Mopani wood.
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All of my snails are covered in eggs except for one. This leads me to believe she's responsible for all the eggs in the tank as if there was another female in the tank she would be covered too, right? I'd love to not have eggs in my tank but can't bring myself to get rid of her...
I have to say that nerites are fantastic algae eaters. I clean my glass once every couple of months and they keep on top of it the rest of the time. I can see their little teeth marks in the little algae that is remaining. Amazing!
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I have to say that nerites are fantastic algae eaters. I clean my glass once every couple of months and they keep on top of it the rest of the time. I can see their little teeth marks in the little algae that is remaining. Amazing!
This is why I'm prepared to put up with the eggs :)
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I have to say that nerites are fantastic algae eaters. I clean my glass once every couple of months and they keep on top of it the rest of the time. I can see their little teeth marks in the little algae that is remaining. Amazing!
This is why I'm prepared to put up with the eggs :)
Me too
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There's just one British species of the family Neritidae, the River nerite Theodoxus fluviatilis.
Apparently it lays up to 200 eggs in one capsule, but only one of these usually develops. The rest act as a source of nutrition for the lucky one. I don't know if anything similar occurs in other nerites, but it may explain why they appear to lay so many eggs.
This species has declined considerably across Europe because of pollution. It's found mainly in larger rivers and lakes and needs hard water. Although it is also found in brackish water, it does not produce larvae which need salt water to develop unlike the apparent needs of the tropical species we keep.
It's quite an attractive species itself and there are numerous pictures on the internet.
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All of my snails are covered in eggs except for one.
I meant to comment on this earlier. What do you mean by covered in eggs?
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They have nerite eggs all over them. Not so much the Black Devil snail I photographed in the other thread, but two of my three nerites look like they've been rolled in sesame seeds (to steal your description!).
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None of my nerites have ever laid eggs on another snail. Wood, yes. Plastic decor, yes. Filter, yes. Glass, yes. But other snails, no.
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Nerites are said to lay eggs on other members of the SAME species, no mention of other species but maybe they aren't so choosy.
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You can see them on my Black Devil snail in this pic http://www.thinkfish.co.uk/forums/gallery-showcase/snail-photos/msg23841/#msg23841 (http://www.thinkfish.co.uk/forums/gallery-showcase/snail-photos/msg23841/#msg23841) and my assassins are also covered in them (so much for the dangers of keeping nerites and assassins apart!).
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I mean together!
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two of my three nerites look like they've been rolled in sesame seeds (to steal your description!).
Ooooer that's a new one on me, mine do the same as Sue. How curious!
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Here's a pic. At least they don't lay eggs on their eggs!
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:o
I've never seen anything like that on any of my snails.
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Me neither.
Skittler
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I'd try and add that problem into the thread title. I wonder if anybody else has the same probllem.
Can you scrape the eggs off the snails.
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I've scraped them off once, but you're still left with a white ring for each egg removed.
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What a nuisance :(
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Well they may not look pretty, but they are doing a great job in there!