Blue corydoras weitzmani

[Carolus]

I thought I'd share this video. I've never seen or even heard about this mutation before and I'd thought some of you would like this.

https://www.youtube.com/watch?v=rVAPHONFUmw

[Narwhal72]

Wonder if it's a hybrid. My Weitzmani hybridized with some metae. Really interesting mutation though.

[catfishchaos]

Wonder if it's a hybrid. My Weitzmani hybridized with some metae. Really interesting mutation though.

Theres always the unfortunate possibility of it being an "art" fish injected why dyes and what not.

[Phish]

I haven't seen that sort of blue color before in artificially colored fish before, but can't say I would rule that out indefinitely.

Possibly a hybrid, maybe between C. weitzmani and C. concolor. Kind of strange though to only affect the top half and it seems only the color is a present trait of the crossbred species. And with that, artificial coloring seems more probable.

I rule out a rare natural color mutation since there was a whole batch of them with this color mutation.

But would a US vendor such as Big Al's really stock artificially colored fish that would normally only come from overseas?
Maybe it is unknown to them.

[Narwhal72]

I would think the rarity of the origin species in the trade would preclude it from being artificially colored. Artificially colored fish tend to be done in low cost, mass produced fish. Not really profitable to do it in a higher cost, low volume fish.

Plus they only had one.

Barring hybridization, it could be the same type of mutation that resulted in the commonly available "Green Tiger Barb" which is just a mutation from the regular Tiger Barb.

Andy

[Phish]

Not quite sure what you mean.

C. weitzmani are found in South America (Peru), as are many other species, and they do get imported overseas. Pretty easily/commonly available/bred nowadays so I wouldn't really consider them a rarity so much. In fact, I believe Ian Fuller was actually one of the first successful breeders a decade ago or so.

In the video, there is at least 3 of these "mutation" corys in the tank. Given that they are all pretty much the same size/age juveniles, I wouldn't be surprised if there was a whole batch/litter of them.

Regarding Tiger Barbs, I am not too knowledgeable on them, but I believe the Green Tiger Bards are just color morphs, selectively bred tiger barbs, all still the same species as the original/wild tiger barbs. So mutation I guess you could say, as in "morph", but not a hybrid species.

And so with this "blue back" C. weitzmani, I suppose the "blue back" trait could have been line bred, so I guess it's a possibility. All the years Ian has been observing all these Corydoras coming and going, if anyone might know whether this is a selective-bred strain or artificially colored, or possibly even a hybrid, he might know.

I am leaning more towards selective bred trait or artificially colored, since I don't really see any tell tale signs of it being a hybrid (body/fins resemble C. weitzmani to me) other than just the coloration (but still doesn't make sense as it only covers the saddle/dorsal region). But I'm no expert

I actually don't know of any selective bred traits in Corydoras, besides the basic albino genes and long fin varieties. Would be intrigued to hear of any line bred traits out there.

[MChambers]

I thought the black Schultzi were line bred?

[Narwhal72]

Phish,

C. weitzmani is commonly available in hobbyist circles. But it is not a commonly available fish in the trade. You almost never see it on wholesalers stock lists and it is not a fish you see in Asia where the dyed and tattooed fish originate from. You would never see this fish in a Petco or Petsmart. Even most LFS never or very rarely have this fish. When they do it is usually a trade in from a local breeder. Last time I saw it on a wholesalers list it was $6. Compared to an albino aeneus at $0.25. It doesn't make financial sense to take a $6 fish and dye it to make it a $8 fish which then raises the price to $25 (a point where most people will not purchase it) when you can take a $0.25 fish and make it $1.50 by dyeing it and then it will sell for $5 which is still a very marketable price.

There is also only one in the video. Not sure where you got three. There are some small loricariids in the tank and one other dark cory that moves through in the background that is unidentifiable.

C. weitzmani has only been in the U.S. for a short period of time (since 2005-2006) and I know because I was an early acquirer of the fish at that time from a Peru importer and bred a ton of them. They are very prolific and easy to breed. The first importer into the U.S. of the fish came to our club and did a talk about how they rediscovered this fish. Of course I paid $20 a piece for them from the importer when I got them but now they sell for less than $5 each as the supply quickly outpaced the demand from hobbyists. They also will hybridize as I had some that hybridized with Corydoras metae.

The Green Tiger barb is the same species as the regular tiger barb. It is the result of a mutation (hypermelanism) that was then line bred. Without knowing the provenance of the parents of this fish we can never tell whether it is the result of a random mutation or hybridization. Just looking at a fish is not a way to tell whether it is a hybrid or not in many cases.

However if a mutation exists in one species of fish (such as hypermelanism like the Green Tiger Barb) it could also happen in other species.

Black Schultzi also appear to be a line bred species. Albinism and long fins are all mutations that are line bred. We don't see a lot of other line breeding because cory's are not a high priority in the designer fish world. Most aquarium owners (I am talking about general aquarists and not hobbyists) think of cory's as clean up crews and are not viewed as something to be attractive in it's own right.

[Phish]

Oh yeah, the line bred black C. schultzei slipped my mind (even though I see mine everyday -.-). Can't think of any other line bred Corys though. Have seen pics of dyed C. Aeneus (albinos).

Makes sense why they aren't commonly line bred for new cosmetic traits and why it would be unlikely to artificially color them given the marketing stand point. Still possible though I guess if someone just decided to, even if just one batch.

So I guess it's hybrid or a natural, but rare-ish occurring pigment deformity? Given that pigment deformities are most likely recessive, it is apparent that someone must be line breeding this "blue back" trait since it was present in multiple corys (yes I see 3 haha). But would the pigment/skin disorder really only affect the top half of the fish (I think it's possible, but not sure)? Alas I know practically nothing on genetics. Just my pondering thoughts.

Don't know what to say about the 3 "blue back" C. weitzmani I clearly see in the video. Pause at 12 seconds (particularly when the fish at the rear swims in front of the orange tile, then have a good look, within a triangle, there are 3 "blue back" C. weitzmani there. I guess you could say the Corydora at the rear (previously in the shadow of the tile) is too unclear/blurry to confirm whether or not it's another of the same Corys, but I see enough of the pattern (2 saddles, blue back, clearly a cory) to say it is. Not trying to bump heads. Just saying.

Hmm, maybe some other Corydoras hobbyist (not sure if you can say enthusiast as the offspring aren't natural/wild forms, so probably still frowned upon like hybrids) out there are working on a line bred strain? Curious more than anything.

[Narwhal72]

I stand corrected. I really had to look to see that one that didn't move. Definitely three. So this does appear to be something that is being line bred.

Considering how easy these guys were to breed I guess it was only a matter of time.

[Coryman]

I think for you to get a the true colors of the fish to show you need to keep them over a natural tan colored substrate. Black substrate will always make your fish go dark.