"Corydoras venezuelanus" Black Cory's"

[rcbows]

Yes I vote A!

My blacks don't look anything like the pic you posted. They are solid black with some rust on the fin ends, but really black!

Ron

[Jools]

The more I think about it the more I don't know. Here is a pic of my hand an a freshly caught C. venezuelanus, and the only other picture of the black Llanos cory that I can find.

[rcbows]

Definitely not the same catfish!

Ron

[Jools]

Definitely not the same catfish!

On what basis? And to be clear, which two are not the same?

Jools

[Jools]

Does anyone has/knows of pictures of living corys from the type locality or does anyone has confirmed catching locations of "our C. venezuelanus"

Yes. Shane did the homework (and leg work) on this and found them "in the right place". I think the type locality may now be urbanised, but the waters in that system and close have the fish I pictured just above in my hand. Shane would be able to give more details.

Jools

[Shane]

Several of the photos in the Cat-elog were taken of specimens collected very near (within 10 kilometers) the holotype location (Rio Cabriales) of C. venezuelanus. As Jools noted the Rio Cabriales is a very small river that runs through the industrial city of Valencia and is mostly polluted beyond the ability to support fish life. The good news is that C. venezuelanus is found throughout the Lake Valencia and Rio Tuy basins. It is the only Corydoras sp in these two basins, which were long ago connected to each other and share about 95% of the same spp.

The most fascinating thing about C. venezuelanus, to my mind, is that I believe it is the only Corydoras sp to exist in a drainage cut off from the Orinoco drainage by the rise of the Andes mountains. Corydoras is absent, for example, from the Maracaibo and Magdalena basins. This may very well be the only Corydoras found north of the Andes mountain chain.

http://es.wikipedia.org/wiki/R%C3%ADo_Cabriales

-Shane

[Shane]

The area in question. This is one of my old collecting maps.
-Shane

[Coryman]

I have been looking into this problem for quite a while and for what they are worth, here are my thoughts. Firstly I am one along with other Cory specialists consider that both C. schultzei and C. venezuelanus to be valid species, which is what they were first described as, it was in the late 70's early 80's that they were in my opinion, put in synonymy with C. aeneus

In the attached image I have placed the two Venezuelan species side by sid and the two C. schultzei forms side by side with the true C. aeneus from Trinidad below.

Both Venezuelan fish have a) a redish shoulder patch and grey coloured caudal fins, I would also say that the body shape is very close.

The C. schultzei forms are slightly more elongated, both show the classic gold arched stripe, although difficult to see in the black form. also both forms has reddish colour in the caudal fins, this is really evident in very young fish.

C. aeneus from Trinidad, has neither the reddish shoulder patch,the arched golden stripe of any appreciable colour in the caudal fin.

So, in conclusion I would say that the Venezuelan fish are the same species and that the darker fish is a regional colour form. If there are any of the dark forms still in the hobby it would be good to get a fin clip and check out the DNA against that of the lighter form.

At this time I am undecided as to whether a new CW-number is warranted.

Ian

[Jools]

Hi Ian,

Having your thoughts down like that is really helpful, thanks. Could I ask about the provenance of the C. venezuelanus pics you've posted? Am I right in thinking the regular picture shows the commercially bred form we see fairly commonly. The black one I am not sure about, but thinking it's wild caught. A key visual characteristic I use is how far the black blotch extends down the body. In the regular fish it does not extend past the posterior edge of the dorsal fin, in the black form, it extends to below the centre of the adipose base.

On the CW front, is a CW number issued to separate things you think are species, things you think are new species or populations or anything you're not sure about and should not be cross bred with things that look (very) similar? I think understanding that as a start would help. I know the corydorasworld.com defines them as new species, but some (e.g. CW071) look more like populations outside of expected distribution range?

Jools

[Coryman]

The dark one I titled C. venezuelanus Black is one of the images you sent me for comparison and I assumed it was one of the fish you or Shane originally collected. It looks to be identical to the Llanos fish. The ones captioned C. venezuelanus are f1's from my original wild fish bred in January 1999.

Sometimes colour patterns can be manipulated, I don't mean through breeding, but by environment. If the normal colored C. venezuelanus were kept in a dark environment and over black substrate they would over a short period of time become much darker and then the pattern would show as you describe, but will then revert back in lighter conditions. I am not sure if the dark fish would do the same in reverse, but it would think it would. I will see if Don still has any of the dark form, it would be a simple experiment to test the theory.

CW coding is primarily for proposed new species. CW071 is in my opinion a completely new species based on it's body/head shape and colour pattern. Its' location also separates it form similar looking species. Many of the C. aeneus looking types are also separated by their geographic isolation as well as morphometrics, examples being C. aeneus, C. venezuelanus , C. schultzei and C. macrosteus.

When issuing code numbers I try to ascertain the catch location as this is important in assessing if there are other known similar looking species in the same area of a river system. The problem here is that fishermen are reluctant, or even point blank refuse to divulge this information as it tells their competitors where potentially their best fish are. The only safe location information is coming from scientists or hobbyists that go collecting and make accurate records.

Ian

[Jools]

The dark one I titled C. venezuelanus Black is one of the images you sent me for comparison and I assumed it was one of the fish you or Shane originally collected. It looks to be identical to the Llanos fish.

Sorry Ian, yes I did send you that pic. I was confused by the fact I sent you that picture as C. venzuelanus and you posted it as C. venezuelanus black. So, that picture in the top left of your pics is C. venezuelanus from near the type locality which is a different river system from where the black/llanos fish is from. The picture in the top right is the same species but is not as dark due to captive breeding/diet etc.

I agree (and defer) to your views on wild caught fishes changing hue through a few generations of captive breeding, especially in the fins and in terms of that metallic look they can have, but they don't seem to lose pigment. The black llanos cory has about a third again pigment further along the body.

I will try to put together a graphic like your very helpful and illustrative one for a similar comparison.

Jools.

[gossei]

I'm going to further confound things here.

I purchased 5 C. venezuelanus from a local vendor, Batfish Aquatics, about a year ago. All five of them looked like the picture labelled as such in Ian's Mon Aug 25, 2014 2:41 pm post. Since then, two of them have darkened considerably and now look closer to the picture labelled "black" than as I originally received them. They remain this way in all conditions. Coincidentally, the dark two are the females.

So, I guess my question is: How much of this is individual variation, as opposed to morphs or location differences or different species?

Blaise

[Shane]

Ian, a couple of further things to consider.

Firstly, I believe calling these something like C.cf venezuelanus "Northern Guarico State" would be more accurate and stop some of the confusion in the hobby between this rarely (if at all) kept fish and other "black" cory spp either natural or man made.

C. venezuelanus is no doubt a valid sp. It is clearly identifiable with a distinct limited range in two closed drainage systems (Rio Tuy and Lake Valencia) situated north of the serrania del interior. As I noted before I believe this makes it the only cory found on the north side of the Andes chain. No other cory spp exist in those two drainages. Habitat is cool, clear water that rarely rises above the low to mid 70s. Currents run fast in most of these streams and the substrate is typical of high gradient streams (rounded stones and gravel).

Perhaps most importantly for our discussion, no fish spp to my knowledge from these drainages is found in the Orinoco system on the other side of the serrania del interior. So if C.venezuelanus and C."Northern Guarico" are the same sp this would represent the only known instance of a Tuy/Valencia fish sp existing in the Orinoco basin as well.

C. "Northern Guarico" is limited to the northern Orinoco feeder rivers with their headwaters in the serrania del interior. These are true tropical rivers rarely seeing temps below the mid 70s. This sp is most often found amongst leaf litter or mud substrates and can be found in the company of other llanos cory spp. It is smaller than C.venezuelanus. I do not have a series of measurements to show this across the two populations but it was something I always noted.

Don Kinyon took both spp home and spawned them. I can't find his spawning reports online but remember that he noted differences in the egg size and coloration between the two.

-Shane

[Mountain]

Hi,
just as I read this here, I found a little group at my dealer here in Berlin, who calls them Corydoras venezuelas sp. "schwarz" and I whish I knew, that this Cory truely exists, comes from Venezuala and is no variation of C. anaeus or C. schwartzi etc.
As Shane says:

"C. venezuelanus is no doubt a valid sp"

- what is typical for this species so that I can recognize it at my dealers?

[Jools]

So, I guess my question is: How much of this is individual variation, as opposed to morphs or location differences or different species?

Ian mislabelled the pictures, the one at the top left is not the black/llanos/northern Guarico fish but is a freshly collected C. venezuelanus.

I don't have the time today to produce the graphic, but I will...

Jools

[Jools]

My dealer here in Berlin, who calls them Corydoras venezuelas sp. "schwarz"

This is a major part of the confusion. Schwarz in German means black in English, compound this with the fact the common black cory in the trade is known by experts as a form of

Corydoras schwartzi

(coincidentally, (I hope) because that name is for exporter Willy Schwartz AFAIK) but is commonly traded as the fictional/trade name "venezuela black" which (because of the mention of Venezuela) is then further confused with

Corydoras venezuelanus

which is obviously different as shown in Ian's group of pics.

Klaus, C. venezuelanus in the trade look very much like the picture shown by Ian (top right). Dark forehead, rusty blotch above the eye mid body blotch that does not go anterior of the dorsal fin base.

The issue I am trying to figure out is that the other, not in the trade species, which we are beginning to call C. sp. "Northern Guarico" and is more similar in shape to the (100%) Corydoras aeneus from its type locality on the island of Trinidad.

Ian has seen C. venezuelanus and C. aeneus (Trinidad) , Shane has collected C. venezuelanus and C. sp. "Northern Guarico" and I've collected C. venezuelanus and seen C. aeneus (Trinidad) and C. sp. "Northern Guarico". Between us, we're trying to find a common view of what they all are AND trying to remove the aforemention confusion with C. schwartzi!

Whew.

Jools

[Coryman]

Jools,
We seen to have introduced C. scwartzi into the mix, I think the (Corydoras venezuelas sp. "schwarz") shop listing is a typo by the store keeper. we are talking C. sp schultzei, which is the parent species of the commercially "Black" Cory.

I would like to add the C. sp. aeneus "Northern Guarico" fish to the CW web site in the "Aeneus group" page, and would therefore like to ask for permission to use the image and relevant location information.

Ian

[Mountain]

Hm......need some help!
What would you do tomorrow, when you have the chance to get this species, although one doesn't really know for shure.......if it is not the announced one?

[Jools]

We seen to have introduced C. scwartzi into the mix, I think the (Corydoras venezuelas sp. "schwarz") shop listing is a typo by the store keeper. we are talking C. sp schultzei, which is the parent species of the commercially "Black" Cory.

Sorry, I shouldn't have gone too far off topic. It's more of a techie/google images issue and I will not go further in to that again as this is complicated enough. This Google search helps illustrate that off-topic point.

I would like to add the C. sp. aeneus "Northern Guarico" fish to the CW web site in the "Aeneus group" page, and would therefore like to ask for permission to use the image and relevant location information.

One image is mine and you can of course use it, the other is Shane's and while I would not want to speak for him, I am sure he would support the wider spread of knowledge about this fish and would give locations on maps. And his picture is better. Anything back from Don Kinyon? He should also have pics?

I _think_ it's closer to the Trinidad aeneus than to C. venezeulanus, but it's a feeling. If anyone else thinks it's one way or the other I'd listen to them too - but aligning it with a species that was much more recently in the lower part of the same river system seems more logical/defensible to me.

Jools

[Shane]

Ian, feel free to use to use my images. I'll check some old thumb drives tomorrow and see if I have more.
-Shane

[Mountain]

I couldn't resist!

[Shane]

The good news, I do have several good shots of both fish and where they were collected. The bad news... they are all on Kodak film slides. Anyone have thoughts on a good scanner to go from slides to digital?
-Shane

[Jools]

Shane,

I don't know if you would like to scan lots of other slides or not while you're at it. Do you have the negatives? In the UK (I'd imagine US too) there are postal based services you can send off the negatives and get a CD with pics on it by return. Same for slides too and if you just want to do a few that might be the option. Perhaps there are local stores which also offer this service on a walk-in basis?

A decent entry level scanner: http://www.epson.co.uk/gb/en/viewcon/co ... view/12034.

Jools

[Jools]

I couldn't resist!

Are they black

Corydoras schultzei

(as I suspect) or

Corydoras venezuelanus

?

Jools

[Mountain]

I couldn't resist!

Are they black

Corydoras schultzei

(as I suspect) or

Corydoras venezuelanus

?
Jools

Here they are....

[Shane]

Firstly, apologies for the off topic post.

I looked at mail in services and scanners. Mail in services are $.33 per slide. As I have something like 700ish fish slides it made sense to just buy a scanner. Plus I can scan in old negatives and slides of family, etc as well. Went with this...

http://www.amazon.com/Jumbl-High-Resolu ... de+scanner

Now to digitize the hours of collecting footage I have on camcorder tapes lol!

-Shane

[Shane]

Scanner arrived and works well. I suspect I will need to experiment a bit to get things just right. Now to digitize several hundred slides and negatives...
-Shane

[rcbows]

Good Luck Shane! I look forward to seeing some of your pictures!

Ron

[Jools]

Just to help folks place the state of Guarico (and as an excuse to post a link to Scots wikipedia), here is a map.

Jools

[Shane]

Nice one. At first I thought it just had lots of misspellings

Also love the anti-UK map showing the country of Guyana's Esequiba region as a "zona en reclamacion." Back when I was living in Venezuela it was illegal to possess a map showing Esequiba as part of Guyana. Nothing like nursing a grudge between Caracas and London from the 19th century

-Shane