pulcher vs. ornatus

[pleco_breeder]

This is going to sound like a simple question, but it really isn't. Nine days ago, I received a group of fish purchased as Cory pulcher. I don't question this particular sellers ability to ID, but it is rather important before moving forward with information that I am positive of the species. These two species can be similar, and they really don't match anything else I've compared them to. Is there a simple way to verify which of the two species I have?

I'll post up one of my BAD pics of them, but don't think it's going to help with ID. As soon as I get a positive ID, I'll post more info as to why this is so important.

Larry

[The.Dark.One]

There are also other similar ones that come mixed in with pulcher:

Corydoras sp(cw065)

and

Corydoras sp(c141)

. Your photo looks more like C141 or pulcher to me but you could have a mixture of species so have a look through for different ones.

The body lines in ornatus tend to be distinct thick lines. C141 and CW065 have more numerous and thinner, broken lines, like your fish. pulcher In my (limited) experience pulcher tends to have a taller dorsal than C141. I think your pic might show pulcher (the dorsal is very tall) but it could be C141.

[Coryologist]

Greetings Larry,

Having received 2 full boxes of the fish in question, on the same order that yours arrived in, I can tell you that you have your work cut out for you. Mine contained C141's, CW028's and C. schwartzi as well as one other species I could not ID for certain, but I believe may be C. incolicana, which was the name the entire box shipped as. Additionally, it appears a few C. pulcher were also in the box, which is odd since it was an order out of Brazil. With that being said, I feel certain that your fish is not C. ornatus, which I have been searching for without success. Of course, my saying this virtually assure

Ah, the joy of importation.

Cheers. - Frank

[pleco_breeder]

There are two things that make me doubt the pulcher ID of these fish. The first is that these don't have the dorsal extension I would normally expect for mature fish. I had no problem accepting the ID till the fish decided to show me they are mature at only 41mm SL.

The second is the lack of recorded spawnings with pulcher. These were going to be a spawning project for next year and I couldn't pass up the price. However, only a week after them arriving they decided to change my plans.

Now, they are on their second spawn after I missed pulling the eggs from the first. I did get an idea of the spawn size from the first spawn though. I got home from work last night and found them still chasing, but was only able to save a single egg from the last "T".

Larry

[pleco_breeder]

I'm not going to complain that these are spawning, but it may get to be a bit annoying if it continues at the same pace. This morning, thinking the L333 female in the tank may have been eating some of the eggs, I removed her to my C. sterbai tank. I was hoping to get a more reasonable number of eggs this evening when I got home. Surprisingly, there was yet another single egg on the tank bottom. The breeders don't seem to be paying much attention to the eggs. They simply push them out of the way (they don't stick to anything) and continue feeding without a second thought. However, I know from the first spawn that they are capable of laying at least a dozen eggs. Regardless, the fist egg seems to be doing well and has became quite clear since moving it to a hatching container hanging in the breeding tank. I didn't realize how much it had changed till I added the new egg and saw them beside each other.

Larry

[pleco_breeder]

At times I get a bit paranoid as my breeding threads fall off the homepage, but I'm trying to keep this updated as best as I can. The first spawn happened last Friday while I was out picking up more fish, so I missed it. However, I'm off work tomorrow and plan to check the tank regularly for more eggs. The females fatten up rather well from one day to the next, but are consistently thinner when I get home from work that night. For that reason, I believe they are spawning daily and I'm missing the majority of the eggs.

I've also been thinking about a way to safely guard the eggs from their parents while I'm gone and think I've got a plausible plan. I'll be going to the hardware store Friday to get the parts to make this happen. I currently have two theories working together about why these aren't spawned more frequently and hope to prove both after I set them up Friday. I honestly believe they are spawning in captivity and just it's not being noticed. Although it's not completely unusual, all the eggs I've seen at this point have been on the bottom of the tank. I had thought I saw spots on the walls where eggs may have been eaten after the first spawn, but haven't seen any signs to prove this in the successive spawns.

At this point, I have two eggs incubating with no new eggs tonight. The females are thinner, so I believe they just ate them. Both eggs are relatively clear, and appear to get more transparent as they age. I have to admit I'm a bit concerned because the first egg is nearly completely transparent and has no visible signs of anything developing inside. However, it hasn't developed fungus yet either. It can sit in the hatching container as long as it takes to either hatch or fungus. It should also be mentioned here that I seeded the hatching container with daphnia pulex at the same time the first egg was pun in. They tend to keep the eggs clean just like cherry shrimp, but also provide a bit of food as fry develop.

Larry

[pleco_breeder]

Hello all,

I have to say I'm getting a bit worried now. There are still no new eggs, but the females may just be recuperating and getting ready for the next bout. However, this is day five and still no visible development of the eggs. I would have expected something to start happening, but can't see any changes happening inside the eggs. There is still no fungus, so I still have to assume they are healthy. I just can't figure out what is happening and am a bit concerned because of that. If anyone has any ideas, I'd be happy to hear them.

Larry

[pleco_breeder]

Hello all,

I'm still trying to verify whether these are

Corydoras pulcher

or

Corydoras sp(c141)

. I took a couple more pics this morning to see if they may help one of the gurus with a positive ID. I've eliminated everything else in the catelog based on info I've gotten from here and my library. However, can't find the description of C. pulcher to verify whether ray counts or some other trait may be able to eliminate it or prove it possible. I did take an assortment of pics, so as to allow a reasonable sample of the group.

Larry

[Coryman]

Allowing for some pattern variability, personally I would say it was nearer to C156, certainly not C. ornatus.

Quite often freshly imported Corys will spawn whatever the conditions, because they were at the point of no return when caught, with the catching, shipping and subsequent release into what are far superior conditions to what was in the shipping bags, spawning was effectively a release. The real trick is being able to get them breeding after a few months.

I would suggest that the conditions are too unnatural for the fish. Ideally there should be a sand substrate to at least give the fish something that is natural beneath them. These fish in the main are filter feeders and should be allowed to behave in a natural fashion, which they cannot do on a bare bottom tank and more to the point the bacterial slime that will be on the glass has a very good chance of causing problems when the fish are trying to look for food.

They may also be happier depositing their eggs in the substrate (some species do), and put them on the glass because there is no where else.

I would also suggest a decent clump of a broad leaf plant as a egg deposit site alternative.

Egg predation is always a problem, especially in clinical (bare tanks) conditions and if the eggs are not very adhesive they will be easily removed.

Ian

C156 from the Rio Purus.

Picture courtesy André Werner and Corydorasworld.com

C. pulcher from the Rio purus

Picture courtesy Hans-Georg Evers and Corydorasworld.com

[pleco_breeder]

I do believe we have a winner.

Corydoras sp(c156)

is a much better match than either of the other options. I also appreciate the advice on their set-up, but have never bothered with the aesthetics.

The sand substrate theories have always been a bit of a confusion point for me. I do use small dishes filled with fine gravel and keep blackworms available to all my corys in them. However, the theories about bare bottom tanks housing some mysterious bacteria with an aversion to sand or gravel substrates doesn't make sense. Having said that, I have noticed a couple times tanks without the blackworm trays develop eroded barbels and attribute that to them being cleaned as they dig for worms.

I also want to point out that these aren't newly imported. They had been in captivity for several weeks before I bought them when their price dropped in order for the seller to make room.

I'm hopeful that they will still be spawning in a few months. So far, after two weeks in this system, the don't appear to plan on stopping for more than 1-2 days at a time. I attribute the lack of spawning the past couple nights to water changes done on the system. The other residents were due for a rainy season, so it had to be done. However, there is still a lot of chasing and the females appear to be full.

For posterity's sake, I do want to make a note about their adhesiveness. When I said the eggs weren't adhesive, I wasn't exaggerating. I watched the first egg I placed in the hatching container be released. It literally rolled out from under the female and bounced a time or two as her tail pushed it away. The second was simply found on the tank bottom the next night without witnessing the spawn.

Having said all that, I am still concerned about the status of the eggs. I would've expected some sort of development, whether fungus or fry, to be visible at this point. If I were to have just found them, I would assume they were healthy second day eggs, but they've been in the hatching container since Monday night with a tank temperature ranging from 82-83 F

Larry

[Coryman]

Larry,

The argument for a sand substrate is a very strong one. Having studied many video clips of Corys feeding, especially comparing the various head an snout shapes. I along with other Cory specialists believe that a sand substrate is an essential part of their basic needs.

There is nothing mysterious about the bacterial slime, it is very evident, just take a piece of filter wool and wipe the inside of a mature tank and see what you get.

Now take a look at the make up of a Cory's barbels and see what they really look like. They are not the smooth appendages as they appear to the naked eye, they are covered with tiny sensory tubicles. Rubbed on plain glass in the manner they do when mouthing for food they will and do become tenderised (Just rub you finger on a glass surface for a few minutes and see what happens, smooth it may be, but abrasive it also is), add this to the abundance of bacterial and you have the potential for serious infection.

The bacterial slime does not form in the same way on sand and the fish do not actually rub their barbels on it, but suck in mouthfuls and eject all but the edible particles out through the back of the gill covers.

Ian

[The.Dark.One]

Not C141? http://www.scotcat.com/thedarkone/calli ... p_c141.jpg

C156 that I have seen don't tend to have black body pigment as in these fish, but seem more grey or dark brown, and don't tend to have a white dorsal fin spine like your fish (like C141 does): http://www.scotcat.com/thedarkone/calli ... p_c156.jpg

[pleco_breeder]

I've never used a true sand in any of my tanks. I have used a small grade gravel as it doesn't seem to compact as much and works well for the blackworms. Having said that, there are differences in what I've seen vs. expelling through gills.

I've had multiple conversations over the years regarding pleco fry deaths on bare bottom mentioning bacterial growth. However, I've never experienced that either and don't put any kind of substrate in those tanks.

The only problem I have seen in cory tanks, and have been unable to verify whether it is caused by lack of substrate, is the occasional bacterial infection on the distal anal fin tip. I don't know why I only ever seen it on the anal fin or if substrate would possibly solve the problem as it is a rare occurrence and easily treated with a short povidone iodine swab. Even then I've only ever seen this with newly imported fish and could also be caused by shipping stress and conditions.

As to the C141 vs C156, I don't know. The pattern more resembles C156 as all the C141 pics I've seen had straighter, "clean", lines. The dark markings on mine are quite a bit more variable. C156 is a good fit, but I don't have prior experience with either fish to know their standard color.

Larry

[pleco_breeder]

I almost forgot to mention that the largest male of the colony has developed a trait which may be able to decide the species question. While feeding this evening, I noticed that his caudal fin has became exceptionally larger, and sharply pointed at the tips, than even the smaller males. I don't really see this trait in any of the photos I've compared to so far. There is also a golden/brown edging starting to appear along the entire distal border of the caudal fin of all five fish.

Larry

[Coryman]

Larry,

I have linked to a couple of movie clips just to show what Corys naturally do on sand.

Once you get the the page you may have to refresh it ti activate the clip, not sure why this is needed, but then I'm no techie.

Ian

http://corydorasworld.com/media/c_ortegai_feeding
http://corydorasworld.com/media/c_ornatus_feeding

[pleco_breeder]

Ian,

The videos aren't available as I'm not a member of the site and requires log-in. I would like to see the videos though.

It is not that I'm adverse to the idea of using sand, but do run into a couple obstacles. The first is the availability of fine sand. I've considered using play sand, but am unsure of the quality of this and haven't been able to find anything that matches a mix of reasonable color. I refuse to keep fish on extremely light color substrate because I've noticed that my catfish don't like to sit on it. I assume this to be because of light reflecting from the substrate.

The next problem would be maintenance. I don't have experience to back it, but most of the reading I've done refers to sand compacting and becoming anoxic at some point in the literature. I wouldn't know where to begin with cleaning tank bottoms. I maintain large colonies of assorted daphnia, shrimp, scuds, copepods, rotifers, and infusorians in all my tanks to help break down waste material to it's simplest form and assist with maintenance during dry seasons. Even after a couple months with no siphoning, there is hardly any waste even in my pleco breeding tanks with only a foam filter operating because of this. It still amazes me that my common Ancistrus tanks are covered with waste at lights out and only a slight bit of brown dust by morning. However, the "dust" that my cleaning crew leaves behind would have no problem settling into sand and creating those anoxic conditions which I can't help other than believing would be hard on the fish. I wouldn't begin to even know how to siphon the tanks without removing the sand.

Larry

[Coryologist]

It is not that I'm adverse to the idea of using sand, but do run into a couple obstacles. The first is the availability of fine sand. I've considered using play sand, but am unsure of the quality of this and haven't been able to find anything that matches a mix of reasonable color.

Greetings, Larry. If I may interject a few points. Play sand is perfectly acceptable as I use it in 75% of my tanks, keeping my "very expensive" sand for my display tanks. Swimming pool filter sand, works, just fine.

I refuse to keep fish on extremely light color substrate because I've noticed that my catfish don't like to sit on it. I assume this to be because of light reflecting from the substrate.

A lot of folks use pure white sand. I have it in a few tanks and the worst I could say about it is it can have a tendency to make your fish looked washed out. That being said, well conditioned C. boesemani on pure white sand, qualifies as "art." lol.

The next problem would be maintenance. I don't have experience to back it, but most of the reading I've done refers to sand compacting and becoming anoxic at some point in the literature. I wouldn't know where to begin with cleaning tank bottoms.

Keep no more than an inch of sand. The normal sifting of the sand during their search for food will keep the sand loose and debris free. They will do all of the work, for you.

Additionally, I'm sure that you will find it much more interesting to watch your Corys relate to and revel in their new and improved habitat. I guarantee it. Cheers. - Frank

[pleco_breeder]

Additionally, I'm sure that you will find it much more interesting to watch your Corys relate to and revel in their new and improved habitat. I guarantee it. Cheers. - Frank

We shall see. I picked up a bag of play sand while out running errands today. I don't think it's physically possible to get it clean, but washed it for nearly an hour in an attempt. I now have a shallow layer in the tank with these corys. I want to see how they do before committing all my cory tanks.

The only unusual activity so far seems to be the largest female wanting to bury herself eyes deep in the substrate. I have seen a couple of them digging (searching for food), but nothing I would consider exceptional so far.

Larry

[Coryologist]

We shall see. I picked up a bag of play sand while out running errands today. I don't think it's physically possible to get it clean, but washed it for nearly an hour in an attempt. I now have a shallow layer in the tank with these corys. I want to see how they do before committing all my cory tanks.

Use a clarifier. Acurel works best.

The only unusual activity so far seems to be the largest female wanting to bury herself eyes deep in the substrate.

That's called, "Cory joy."

I have seen a couple of them digging (searching for food), but nothing I would consider exceptional so far. Larry

Uh, just what are you expecting, Larry? The simple fact that you are providing your Corys with their minimum requirements for a more healthy and "natural" existence, should be sufficient. I would not expect them to do cartwheels or start singing opera. Realistic expectations are your best bet. Cheers. - Frank

[pleco_breeder]

I didn't expect anything exceptional, but am surprised that they are staying clear of the areas covered by sand for the most part. The back corners are still bare glass. I still have to wash more sand to finish. They are staying in those areas short of a few momentary excursions to check the new substrate. Maybe they'll get used to the change and become more adventurous, but they still appear to be wary of the new surroundings. I expected to see some kind of preference, and so far it's not looking good for sand.

Larry

[MatsP]

I believe pool filter sand tends to be cleaner (and a bit more expensive) than play-sand. I use something called "Kiln dried paving sand", which is intended for brushing/sweeping into the cracks between blocks when doing block paving. It is similar to play-sand, just a tad coarser and generally a lot cleaner than playsand. I don't know if this is available in the us - I paid £3.49 for 25kg today - approx $5 for 55lbs. Of course, your mileage may vary, as they say.

--
Mats

[pleco_breeder]

I paid only slightly less for play sand, about 4.50US for 50 pound. The thought of using paving sand never occurred to me. Since this is still experimental for my part, I'll suffer through this first time and definitely use it the next if it improves the corys behaviors as much as Ian and Frank say.

Thanks for the tip,

Larry

[Nabobmob1]

I didn't expect anything exceptional, but am surprised that they are staying clear of the areas covered by sand for the most part. The back corners are still bare glass. I still have to wash more sand to finish. They are staying in those areas short of a few momentary excursions to check the new substrate. Maybe they'll get used to the change and become more adventurous, but they still appear to be wary of the new surroundings. I expected to see some kind of preference, and so far it's not looking good for sand.

Larry

It may be the sudden change.

Drop in a ridiculous amount of blackworms (more than a an average feeding) and watch them as they borrow and dig for the stragglers that remain through out the day. My C118 will almost completely bury themselves when startled.

[pleco_breeder]

That was going to be my next question. How do blackworms do in sand? I keep a literally constant supply available to my corys to munch on by maintaining them in small dishes filled with gravel in the tanks. If they start to thin too much, I just switch the dish out with a pleco tank, which aren't as effective at getting them, to recuperate for a couple weeks till they repopulate. If the blackworms do well in sand, it would be just as easy to colonize the substrate.

Larry

[Nabobmob1]

If the blackworms do well in sand, it would be just as easy to colonize the substrate.

Larry

You may find it more difficult at sustaining a population in sand as the corys will be much more effective at getting them. hardscapes do give them a few places to hide.

[pleco_breeder]

I stock them so heavily that there are usually a few blackworms out "taking a stoll" along the bare bottom tanks with no interest from the corys. They're just in there for between meal snacks ;)

I make sure that all of my fish have something constantly available as food with exception of tetras in breeding tanks. I'm even considering trying to acclimate some of my daphnia over to blackwater for that purpose in hopes to cut down on egg predation a bit. With most species this has helped quite a bit with conditioning. Even in those that it doesn't directly help condition, it seems to help with growth, color, activity level, and limiting egg predation. That's still not a bad thing. Besides, I would be more than happy to order more often if the corys were better for it.

One thing that I noticed with the sand while feeding last night and this morning is they are a lot slower to start feeding that usual. Normally, I start dropping food in and they're already swarming to find it. Both feedings have taken a few minutes before they even start moving. I thought it may be the change last night, but I'm not so sure now.

Larry

[Coryman]

Larry,

A picture of C. ornatus feeding in sand.


Image courtesy Ian Fuller & Corydorasworld.com

I tend to use the finest best quality sand I can find, price is actually immaterial, I pay around £22 ($34) 25kg of very fine washed river sand. This will last me about 3 years. I fail to see the logic in buying the cheapest sand around, it usually needs a lot of work before it is usable, when you pay small fortunes for the fish you want to keep. I certainly like my fish to have the best I can give them. Its like putting remould tires on a Ferrari.

Regarding you comment about sand compacting, you are right it will if you have it to deep, I normally have a depth of 12 to 15 mm, this allows the Cory's to get right into it and keep it free.

Putting sand into a tank and expecting the Cory's that have been accustomed to living over plain glass to take to it straight away ain't going to happen. The same as they would have taken a little while to get accustomed to the plain glass bottom when you first had them.

Regarding Daphnia in 'Blackwater' I am not sure how you will achieve this because I don't know how you will keep the Daphnia itself nourished, because without food in the Daphnia it is just an empty shell. Will be interesting to see how that experiment works out.

Ian

[pleco_breeder]

To put a bit of closure on my sand debate, I thought it would be proper to put up a post. I have noticed a couple things. First, the fish in question seem to be holding size better with sand. They were feeding heavily when food was introduced, and slowly "deflating" between meals. They've grown substantially, but because of this they were not really conditioning as well.

Second, I set-up my hastatus in a separate rack of their own yesterday, and had quite a few straggler blackworms on the tank bottom. I siphoned these and put them into the sand tank. It is correct to say the corys can catch the worms more effectively on sand, but have also seen quite a few make a hasty retreat into the sand. With a large enough start, I believe it would be possible to maintain a steady colony in a sand substrate.

Third, and final, the largest male in the group has improved color dramatically since the tank has cleared. He has gone from only a slight amount of iridescent green on the gill covers and body to being nearly covered by a range of colors from tan to gold to green. I have to assume this means he approves ;)

With that out of the way, there is still some question of the species. There are currently three viable options: C141 based on the white dorsal spine, C156 based on the pattern, and still considering C. pulcher because of dorsal and caudal fin shape. None of these matches perfectly, so I'm starting to wonder if this isn't something else completely.

[pleco_breeder]

Ian posted while I was getting pics for the last post, so I'll make a couple notes. Likewise, cost really isn't an issue with my fish or their surroundings. However, it is difficult to find a reasonable natural sand where I live. Even though I could buy ADA or eco complete with only a two hour drive because of a strong planted tank community, finding something other than black is nearly impossible. I've even gone to looking online for a mix of natural looking earth-tones for an aquascaped tank I'm working on getting parts for with no luck. It still doesn't make sense to me that the planted tank community, which prides itself on beautiful natural scenes, buys sand that would never occur in nature. It's like creating the perfect tank and loading the bottom with neon pastel rainbow gravel ;)

With regards to the daphnia, I have a couple unusual uses for them. Not the least of these is assisting with keeping eggs clean when I'm low on cherry shrimp. My tanks are never going to be as sterile as true blackwater. There are always small copepods and rotifers in them because I introduce them when setting them up. They feed on leftover food and break down any mulm that accumulates. This keeps the tanks cleaner than they would be and provides food for fry. Most of my blackwater tanks are used for spawning tetras, and I normally don't have to feed them anything till they are able to take decap brine because of this. Some do still get slight feedings of golden pearls, but I don't know that it is necessary. It took nearly two months to get the tanks, all on a central system, to the point that they would sustain this. I have blackworms in one of the tanks, and they actually seem to be reproducing better than in my standard tanks. If I'm able to introduce a sustainable colony of daphnia to the system, I simply hope for the same. Even if they are only feeding on leftover food, and cleaning eggs, they will be well worth the effort. Luckily, daphnia are not really obligate feeders of any one thing.

Larry