bekateen wrote:These do look like bladder snails. I was under the impression, perhaps mistakenly, that these were just young Ramshorn snails. But they probably aren't.(
Ramshorn snails have a shell without an obvious spire. The shells are "planispiral", which means that, when you hold the shell across its widest part, it is all in one plane, like a Rams horn, or a coil of rope. Have a look at <http://www.planetinverts.com/ramshorn_snail.html>.
I definitely had some real Ramshorn snails in the cup, plus one or two shaped as seen above. As I think I said earlier, I was working under the assumption that they were all the same kind of snail, with the spiral shell snails being juvenile forms of the larger Ramshorn's.
I think ramshorns are available obviously sold as ramshorns, you could probably keep them in another container, separately from fish or other snails, they breed just as fast the others as far as I know, becoming a pest if you let them
bekateen wrote:These do look like bladder snails. I was under the impression, perhaps mistakenly, that these were just young Ramshorn snails. But they probably aren't.(
Ramshorn snails have a shell without an obvious spire. The shells are "planispiral", which means that, when you hold the shell across its widest part, it is all in one plane, like a Rams horn, or a coil of rope. Have a look at <http://www.planetinverts.com/ramshorn_snail.html>.
Hi Darrel,
Thanks for these links, it seems you were debating on inocuity of Ramshorn snail on fish eggs.
I've never had any problem with Red Ramshorn ("Planorbis" rubrum) snails either, although the jury seem to be out on these.
Again it isn't in any way conclusive (lower pH/dKH may have stimulated egg laying in the Cories or I may have been using cooler rain water for water changes), but my suspicion is that the Ramshorns were eating the eggs.
. Hopefully these experiments in a somehow more controlled environment, like a small plastic cup will encourage you to test Ramshorn snail again, to give them another chance!! ;)
Here is a compilation of fish species tested with some degree of success (no fungus reported) with Ramshorn snails:
Okay, here's my final report with these 40 eggs: In the end, only one egg hatched from the group without snails. I thought a couple more would hatch, but they didn't. And in the end, all the eggs disappeared in the group with snails. So either the eggs failed and the snails ate the bad eggs, or the snails were eating good eggs.
What I found interesting was this: Even though eventually all of the eggs disappeared in the + snails cup, by contrast in the first two-three days almost all the eggs were untouched (and not fungusing; these eggs looked viable).
It was only on days 3 and 4 that the eggs started disappearing, and a lot of snail poop was visible in the container. I think the snails were ignoring the eggs (and maybe eating any new fungus) in the first two days, but these snails had been placed in the cups with full stomachs (or nearly so). Then as days past and the snails got more hungry, I suspect that is when they started eating the eggs.
bekateen wrote:...It's been four days now. All 20 eggs in the bowl without snails have fungused; in spite of that, one has hatched, and a couple of others look like they may still hatch.
By contrast, there is no fungus in the bowl with the snails. However, most of the eggs have disappeared; there are only about 4 eggs left. I've never witnessed the snails eating the cory eggs, but I'm noticing now that some of the snails look different than others, so I might have some snails in there which do like to eat eggs.
Here are photos of the snail I suspect is not a ramshorn snail and might be an egg eater. Does anybody recognize this snail and know its ID?
bekateen wrote:Okay, here's my final report with these 40 eggs: In the end, only one egg hatched from the group without snails. I thought a couple more would hatch, but they didn't. And in the end, all the eggs disappeared in the group with snails. So either the eggs failed and the snails ate the bad eggs, or the snails were eating good eggs.
What I found interesting was this: Even though eventually all of the eggs disappeared in the + snails cup, by contrast in the first two-three days almost all the eggs were untouched (and not fungusing; these eggs looked viable).
It was only on days 3 and 4 that the eggs started disappearing, and a lot of snail poop was visible in the container. I think the snails were ignoring the eggs (and maybe eating any new fungus) in the first two days, but these snails had been placed in the cups with full stomachs (or nearly so). Then as days past and the snails got more hungry, I suspect that is when they started eating the eggs.
Cheers, Eric
So snails did what they are suppose to do: eating fungus. On the other hand why the cleaned eggs disappeared stay a mystery... There was two different kinds of snails so it is difficult to know exactly which one bites first.! Also it could be "no water change" which will impact on egg survival. I made earlier a test with very large Ramshorn and eggs hatched. I am running another test with one egg ready to hatch (it hatched the day after I put it, I took out the fry) three eggs that look ok, two that look infertile, all these in a cup with lots of snails (ramshorn, see picture), a couple of days after the three supposingly good are still around. The cup is very dirty... There should be one snail hungry among all of these.
Interesting. When I get more eggs I'll try again. I'll choose my snails so that no matter their size, they will all be Ramshorn, with no bladder snails.
Although I had only one hatch in the cup of eggs without snails, none the less it did hatch. This makes me wonder how many might have hatched if I had used only Ramshorn snails the first time.
It is always difficult to conclude from one experiment. Here I kept infertile eggs with fertile ones for few days after all fertile ones hatch, then they disapeared one by one. Did they desintegrate or were they eaten by snails...?
francoisMtl wrote:....In fact, it is so efficient that you can keep fertilized and non fertilized eggs with the snail in the same container, even some plants will not affect the development of eggs. Snails will clean everyone and none will fungus. As you can see here, there are still some unfertilized eggs that I kept in the container for a test. They stayed 4-5 days the time the good ones hatch, you can see the newly hatched one on the picture.
You can see two or three very white eggs.
Cheers,
francois
I've never seen ramshorn snails eating corydoras eggs.
Normally, when eggs are not viable they become extremely soft. If you happen to touch a "white" egg after a couple of days, it just melts away/dissolves in water. Viable eggs get dark and sort of hard and I've never seen neither my snails, nor my shrimp eating them. I've got all sorts of snails including ramshorns.
I haven't read the entire thread so this may have been suggested already but a good way of preserving viable eggs is to place them one by one apart from each other on the glass of the tank in which you want the fry to hatch, and have high flow(filter outlet) blowing at the eggs. It's quite the play to do it but the last time I did that I had a very high hatching rate. If the eggs are bunched up, not subjected to flow and oxygen, then a lot if not all will fungus.
As a matter of fact, the corys themselves if given the conditions, lay eggs in very high flow areas. I currently have a bunch of eggs sitting on the tank glass exactly under a filter outlet that actually splashes into the water. The cory mom that did it must have been laying sideways because she's put them very near the surface. In my previous tank they layed the eggs on a 2800l/h powerhead. Don't ask me how they did it but they loved to spawn there. So I'd listen to the corys, they know better. Hatching them in a bowl is very hard, you need lots of movement and oxygen. And raising fry in a bowl is near impossible. They need perfect water conditions to survive the first few weeks. They grow fast in the right conditions and will pollute the container in no time.
eggs, just laid 8 hours ago. Three Ramshorn snails and NO bladder snails (sheesh!). Water depth 12 mm. I'll perform daily water changes.
I've never had trouble hatching tril eggs in the past, but I do have pretty high mortality in the first month or two. Even so, if I get more eggs hatching this way, it should help my ultimate yield.
I've never had trouble hatching tril eggs in the past, but I do have pretty high mortality in the first month or two.
Hey. Good luck with the new batch. In relation to mortality, it's always due to water quality, overstocking and overfeeding the tank you raise them in. If 60 fry hatch, you won't be able to raise them in anything smaller than 30G and even then in about a month you'll be severely overstocked and if not dead by then, they'll start dying. There was a poster years ago on another forum who raised and sold corydoras non-stop. She raised the fry in a 5f 120G tank. Otherwise how do you grow 60-100 corydoras at once, given the high protein food they should be fed at the start and the fast growth rate....?
This below is one of my old videos of a fry that is 3 weeks and 5 days old(the big one in the video). It's just to give you an idea of how fast corys grow.....hence you need decent sized tank and filtration.....The little ones in the video were less than two weeks old that day.
Some of my cory fry at 5 weeks old. In shops I see most corys sold at that size.
Thanks for the advice. Yes I've always assumed the problem was a combination of maintaining water quality and not overfeeding, with a simultaneous complication of competition from a cohort of aeneus fry at the same time (because in my tank the two species always seem to breed at the same time, and in fact that happened again yesterday). The aeneus are much faster growing and stronger as fry than the trils. So although I usually hatch them together (but not in this case because of the snail expt), I have to sort out the trils earlier than the aeneus to move them to grow out tanks.
The aeneus are much faster growing and stronger as fry than the trils. So although I usually hatch them together (but not in this case because of the snail expt), I have to sort out the trils earlier than the aeneus to move them to grow out tanks.
I once made the mistake of trying to grow out melanotaenia fry with other Cory fry of the same age. The melanotaenia so dominated at feedings and were so much more active that the other Cory fry barely survived.
Albino aeneus are not tough at all. They are quite inbred I think and the fry quite sensitive. Normal aeneus could be tough but I haven't kept any.
The coloured ones you are seeing in the video are a cross between albino aeneus and gold laser corys. I don't know how fast pure gold lasers grow when fry but a 6 week old "hybrid" got as big as their several years old gold laser father,just to give you an idea. All albinos grew smaller by about 2 weeks difference in size. But I could have still sold them at 8 weeks if I wanted to. I've seen them sold that small in most shops.
I'd think the issue is not competition as much but who's the toughest in a small overstocked tank...If you have the space, try raising fry in a large tank with decent filtration and lots of water changes, and you may find that all survive, regardless of species mixed. It's all about the water quality. If you have a large tank, you can afford to feed more so there's no competition.
Thanks again. I agree that albino aeneus are really inbred, but in my experience they are as tough as nails, high hatching rates, and good survival. No matter though, as I mentioned above I also agree that the main issue is probably water quality. As my fry age, I sort them by size and pull out the fastest growing and move them to the larger tanks first, leaving the smallest behind so that they are not subject to the competition with the larger siblings. I don't have the luxury of scale to transfer them all to one or two really big tanks; therefore I just try to juggle and manage the resources to meet the demand. I do have strong aeration and an oversized sponge filter in the hatchery tank, and I keep a combination of a sponge filter and a HOB filter on each grow out tank.
Free access to food and lots of water changes are keys for fast fry growth.
Here, eggs hatch in small cup with one or two water change per day, then newly hatched frys are move to 2L (1/2 gallons) container with one liter of water, one air line, some plants, microworms, fry food, adult crushed food water change as much as possible (usually near or over 90%) daily. This is for 15-30 days then they are moved to 5 gallons with same diet, sponge filter (1 and now 2), and 60-80% water change each two days. On this picture they are part of 195 fry (few Aspidoras, lots of CW010 and panda). Growth rate seems to be species dependant, CW010 grow faster than panda.
To come back at snails as live eggs fungus protecting agent. I incubated 19 venezuelanus black and 7 panda eggs with lymnea kind of snails and 18 venezuelanus black and 8 panda eggs with Planorbus.
Got 15 hatches with planorbus and 2 with Lymnea (pond snail). From the way their shell turn they must be pond snail (Lymnea) and not bladder snail (Physae), but not to sure about it... I took th efry out as they were hatching but can still see 7 of them in the magnification pics, plus 2 empty shels from newly hatched fry and few more with eye inside ready to hatch.
Something went wrong with pond snails and the only difference between the two cups were snails species (the chance to peak all bad eggs for one cup and mostly good one for the second cup is very low, plus I did not notice more eggs turning white in one cup versus the other).
Cheers,
francois
Okay, today my trilineatus eggs are hatching. Over the last four days, none of the eggs developed significant visible fungus (although a couple of eggs appeared to have very small halos around them; I don't know if this was fungus, or even if the snails ate it later). Three of the eggs turned white by the end of day 1, and I removed them. There were also a few eggs that looked off-color (but not white or solid) on day 2 and day 3; I don't know what happened to them; I suspect that they either disintegrated or were eaten, since the total count of eggs is slightly lower today than the original number (see my counts below).
So far, I've counted about 40 hatchlings from the original 62-65 eggs; there are still at least 18 unhatched eggs in the container; these all appear to be viable, so my hatching rate should increase further.
There's a lot of ramshorn snail poop all over the container, and even several egg masses.
I performed daily water changes, and this was actually very easy: As you can see in the photo above (in my previous post), I floated the plastic container on the water surface of the parent aquarium. By floating the container in the aquarium water, this allowed the heat from the aquarium to transfer into the plastic egg container, maintaining the eggs at a constant 80F. When it was time to do a partial water change, I tipped the bowl gently towards one side, allowing water (but not eggs) to spill over the side of the container into the aquarium. To refill the container, I simply dipped the edge of the container below the water line of the aquarium and allowed some aquarium water to flow over the rim into the container (slowly, so as not to accidentally wash eggs back out), until the container was back to (approximately) 1 cm depth.
My closing observations on the trilineatus eggs: This morning, five eggs remain unhatched but appear viable. Fifty two fry are in the container; four of these are dead.
Okay, one more trial, just for fun. This time, fresh oil cat
eggs (68 of them) which were laid overnight. The setup is exactly the same as last time - 1 cm deep water, no active aeration or circulation, the container floating on the water surface in parents' aquarium, daily ~75% water changes taken from parent tank, with three medium sized Ramshorn snails. Let's see how this ends.
To clarify the photos, the plants you see in the photos are not IN the egg container, they are in the main aquarium, UNDER the egg container.
Congratulations on another spawning! Hoping the snail and egg combination works well here also. I'm hoping my ABNs will also do so soon, it's looking imminent, but then it has been for some time now.
Alas, this test with the oil cat eggs is already a failure. Within an hour of moving the eggs to the container, the eggs started lysing (bursting open); I actually saw one burst with my own eyes.
This type of response, in my mind, makes me suspect that there was an osmotic problem with the eggs in the water. However I can't see how this could be the case, since the egg container water was taken out of the same tank in which the eggs were laid. The other possibility I can imagine is that these eggs were so fresh that they were extremely fragile and hadn't hardened up yet (which I know happens to cory eggs, but I don't know if this also occurs to oil cat eggs). Maybe I should have left these eggs with their mom in her cave for another day before transferring them to the incubation container.
Within a few minutes of this picture being taken, the number of apparently "intact" eggs had dropped from the 68 of my original count to less than 20! And in case anyone is wondering, I saw no evidence that the snails had anything to do with the eggs bursting. The one egg I saw burst was nowhere close to any of the three ramshorn snails.
Not sure if there's a time after which the eggs harden, as I've no experience with centromochlus perugiae whatsoever to know. Could the large diference in water volume ie the tank and container been a factor, and do either of the parents care for the eggs in anyway, I might seem a bit naive, but just some thoughts.
Water volume shouldn't matter, but a change in the relative water tonicity would matter. Tonicity = a relative measure of the water diffusion force created between two water solutions separated by a membrane - in this case, the water in the container compared to the water inside the eggs; when there is an imbalance in the tonicities between two solutions, water will spontaneously move across the membrane, either INTO the cells causing the cells to swell and lyse (as seen in my cells) or OUT OF the cell causing the cells to shrivel. Obviously, neither of those actions is good for eggs. Tonicity is imperfectly linked to the relative osmolarities (concentrations of all solutes, salts, proteins, whatever, in the water). Although not universally true, water solutions with more ions and other substances dissolved in them (i.e., higher TDS) will be hypertonic compared to water solutions with fewer solutes (i.e., lower TDS), and these higher TDS solutions will leach water out of the lower TDS solutions.
Since the eggs were laid in the tank last night, the eggs were deposited into a certain quality of water with a particular TDS (which I didn't get a chance to measure this morning). I took water out of that tank to fill the egg container, so the osmolarity should be identical, and thus the relative tonicity should be unchanged - I.e., if the eggs didn't lyse in the aquarium, they shouldn't lyse in the container either.
There is some parental care performed by female oil cats: The eggs are laid on the walls of a cave (like many plecos) and the MOTHER (not the father, as is the case for most plecos) stays with the eggs and guards them. However, I don't know how much active care of the eggs occurs: When I watch my mothers with their eggs, I never see any strong "fanning" activity by the moms; if anything they seem disinterested in the eggs, but they do stay with them. So maybe there is some fanning, but I haven't observed that personally.
MChambers wrote:Would adding methylene blue change the tonicity?
Good question. Anything soluble in water, but which CANNOT penetrate the cell membrane, will change the tonicity. If the methylene blue is able to enter the egg cells, then it will not change the tonicity. If it is trapped outside of the egg cell, then it will change the tonicity.
To be clear, I did not add any methylene blue to my container. If the ramshorn snails are controlling (eating?) the fungus, then no medication should be necessary.
Hi Eric,
Sorry for your loss...
At first I wanted to ask you if you were sure these eggs were fecund. But I saw your post (http://www.planetcatfish.com/forum/view ... =7&t=42368) and that is not their first spawn... Did you notice low fertility in the firsts spawns?
Congratulation for your Corydoras trilineatus, very nice pictures and detail report.
So we can add this species to the list. Here I got success with Corydoras aeneus and right now I have some Corydoras paleatus eggs with ramshorn snails, should be able to report the output in few days.
