Corydoras Species "groups"

[jollysue]

While we have you here, Tolak, what do you know about species groupings from your experience your studies?

Do they look at this subject with angels and discus? I believe I heard they are still capturing new species of discus in the wild.

 

[Tolak]

There are only a few actual species of angels, the ones most commonly found are Pterophyllum scalare, these are the ones that are silver with black stripes in their wild form, and the one all the different phenotypes originate from. There is also Pterophyllum altum, which are a bear to keep, and near impossible to breed, and Pterophyllum leopoldi, previously known as Pterophyllum dumerilli, but as always in aquatics there are debates as to whether these two are the same or distinctly different species.

With angels the biggest concern is genetics; how the different color morphs appeared, and the bloodlines behind these various phenotypes. The Angelfish Society has some excellent info on the history & genetics behind all this, it is a bit of reading; [URL="http/theangelfishsociety.org/genetics.htm"]http/theangelfishsociety.org/genetics.htm[/URL] [URL="http/www.theangelfishsociety.org/phenotype_library_2007/"]http/www.theangelfishsociety.org/phenotype_library_2007/[/URL]

The genetics behind angels is more standardized than with discus. Discus will be more easily sold with some trendy name than angels, which is a shame in my opinion. I'm guessing this is due to discus being consideably more difficult to breed than angels, so there are fewer breeders. This gives a smaller amount of information for anyone wishing to research the genetics behind discus.

There was an article a couple of years back about a new species of discus, the link is on my other computer, along with a dead power supply. With the size and area covered by the Amazon I'm sure there are yet undiscovered color morphs if not species of both angels and discus.

 

[jollysue]

Now that's what I'm talkin' about! LOL And this conversation was started by a 15 year-old young man! Who got shot down.

Genetics is of course the biggy. As you probably know, Tolak, the list of Callichthyidae (the catfish family that includes Corydoras, Brochis, Aspidoras, and Schleromystax--the ones we deal with most in this forum) is growing by the second with newly discovered, unnamed and unclassified fish. This family of fish has been highly successful in the whole of Central and South America.

As mentioned elsewhere in a discussion with Cory_Dad, DNA is now the tool that the taxonomists/scientists want to develop for use to classify and reclassify.

I don't know for sure what all the Cory societies are, but I do know of the Corydoras Study Group and know some members from the internet. I like the idea that the people who know the Latin names and groups and can read the German and knew the people who first captured Corys in the wild, will drop by once in a while and share with us. That while still being able to chat at a more fundamental level about the fish we just got at the lps.

One of our favorite "groups" the "elegans group" which includes the "San Juan" bilineatus, the bilineatus, the elegans and the napoensis and which many Cory owners have (I have 2 species "San Juan" and pantanalensis) Ian just told us in his post is in debate now. The scientists are considering making a new genus. It is the first time I had heard it and it made me very excited. I don't know why! I guess 'cus I have some.

Thank you, Tolak. These things are a bit cutting edge I suppose and although there are opinions about what should be done, the answers are scientific. It involves more than "When do you feed your Cory?"

 

[Cory_Dad]

Be careful Jollysue that you don't too much hope into the DNA testing.

Yes, it will give you the genome pairs but it still won't do the classification for you. Remember, someone still has to set up the rules and templates of which pairs have to be satisfied to be called X or Y or be a member if family A or B ie. what constitutes family A or B in the first place?

All it will do at this point is to be able to tell you that 'this cory' has the same genetic make up or profile as 'that cory' which in itself is extremely useful.

It would also be helpful to know which genes do what (colour, fin size/shape, etc.).

We live in exciting times.

Cheers.

 

[jollysue]

We do indeed!

You are of course right on, Cory_Dad. Very much is arbitary in many "scientific" fields, including taxonomy. I think it might be useful though in determining these "groupings" / closeness of relationship. Although most likely, as you say, the boundaries will still require human choices.

Many fish are in the C. aeneus species that have no connection in water ways at all. There are many debates and opinions. It is hoped I believe that DNA can help. But still the boundaries as you say must be set by humans. The DNA can only at best track the path I think.