Ok, this might not be of interest to most people, but I'm starting it in response to a recent thread on identification in which this topic came up.
I am not a taxomist and due to that fact I sometimes find it difficult to keep up with all the 'rules' and such, but here is my best attempt at some background general taxonomic information before we discuss this species in particular. Probably review for many people, but bear with me.
The person who first describes a species has the right to name it. By describe, I mean a detailed description of the animal, it's range (or at least where the specimen was found), it's morphological characteristics, etc. It also needs to be published in a respected scientific, peer reviewed journal. Normally, the animal which the scientific description is based off of is deposited in a museum, and this specimen is called the type specimen or Holotype. When possible, additional specimens of the same species are collected at the same time to support the species desbription. These specimens are called Isotypes and are often deposted in different museums. Spreading specimens out among different institions, on which species descriptions are based helps make them readily availiable to researchers and makes it more likely that they (at least some) will be preserved. The 'priority' of specimens can be further broken down, but I think this will suffice for our purposes.
There are many potential pitfalls that arise. Many species descriptions were done a long time ago. Preservation methods are better now than they used to be but sometimes these origional type specimens no longer exist, or are in really poor condition. Often times when this happens scientists can go back to the locality where a species was collected but this does not necessarily mean that they can still find an animal (or plant) that looks like the species that was described. On top of that, imagine trying to accurately pinpoint your locations in say the peruvian amazon in 1800's. There were no GPS tools to help you out back then.
Reguardless of all these pitfalls, the person who origionally names the species has priority in regard to the species name.
Now add on, taxonomy evolves. So perhaps the first person who discovers a really wierd looking beetle (which I'll give the common name Pincer Beetle) thinks it looks similar to a beetle called Largus pincerus. He believes it must be in the same Genera as this beetle he is familiar with so he name it Largus newus. Later, scientist discover that our Pincer Beetle really is a member of a new Genus. The first person to name this new Genus really likes mountains so he names the species he discovers Mountianus peruensis, because he happened to find it in Peru. So now our Pincer Beetle's name would be called Mountianus newus, because the guy who origionally named it still has 'priority', but he got the Genus wrong, so the first person to correctly name/describe the Genus will lend his name to this beetle too.
Another complication is that sometimes scientists later discover that what they thought were different species are really the same. Let's take an easy example of how this could happen. I think most people are familiar with the North American bird called the cardinal. If you didn't know better, one might think that the males and females are 2 different species. Their coloration is quite different. I do not know the history of cardinal taxonomy, but the person who origionally desbribed and named it could easily have thought they were 2 different species. If that happened, the first published description would be the correct scientific name and the second would be considered a synonym.
If you haven't fallen asleep yet, let's talk about Potamotrygon hystrix. This species was first described in 1834, quite a while ago. I have thus far not been able to find out of the type specimen exists or get a copy of the origional publication, but you can find a summary in the Check list of the freshwater fishes of South and Central America which you can find here: http://books.google.com/books?hl=en...ts=m6BZyR1rUO&sig=Glu4We7nOYoxLC0pB-pfpcXZczg . Summary for P hystrix is on page 24.
As you can see, this species was origionally called Trygon hystrix. It's range is the Parana-Paraguay River basin, with some question on which contries it's range includes, but Brazil is definetly not on the list. It's not even in the Amazon basin! Now, there is some controversy surronding this still, so things could still change (and often do in taxonomy) but right now this is what is accepted by the scientific community.
The ray that the hobby/aquarium trade calls 'true hystrix' (can someone please post a picture of this fish on this thread for people to see?) is found in the Amazon in the Rio Negro in Brazil. I find it highly unlikely that it is the same species. The riiver basins are no where near each other. http://en.wikipedia.org/wiki/Paraná_River The scientists at the symposium in Chicago said it was an undescribed species.
Hope everyone doesn't have a headache! If you got this far, thanks for reading.
E
I am not a taxomist and due to that fact I sometimes find it difficult to keep up with all the 'rules' and such, but here is my best attempt at some background general taxonomic information before we discuss this species in particular. Probably review for many people, but bear with me.
The person who first describes a species has the right to name it. By describe, I mean a detailed description of the animal, it's range (or at least where the specimen was found), it's morphological characteristics, etc. It also needs to be published in a respected scientific, peer reviewed journal. Normally, the animal which the scientific description is based off of is deposited in a museum, and this specimen is called the type specimen or Holotype. When possible, additional specimens of the same species are collected at the same time to support the species desbription. These specimens are called Isotypes and are often deposted in different museums. Spreading specimens out among different institions, on which species descriptions are based helps make them readily availiable to researchers and makes it more likely that they (at least some) will be preserved. The 'priority' of specimens can be further broken down, but I think this will suffice for our purposes.
There are many potential pitfalls that arise. Many species descriptions were done a long time ago. Preservation methods are better now than they used to be but sometimes these origional type specimens no longer exist, or are in really poor condition. Often times when this happens scientists can go back to the locality where a species was collected but this does not necessarily mean that they can still find an animal (or plant) that looks like the species that was described. On top of that, imagine trying to accurately pinpoint your locations in say the peruvian amazon in 1800's. There were no GPS tools to help you out back then.
Reguardless of all these pitfalls, the person who origionally names the species has priority in regard to the species name.
Now add on, taxonomy evolves. So perhaps the first person who discovers a really wierd looking beetle (which I'll give the common name Pincer Beetle) thinks it looks similar to a beetle called Largus pincerus. He believes it must be in the same Genera as this beetle he is familiar with so he name it Largus newus. Later, scientist discover that our Pincer Beetle really is a member of a new Genus. The first person to name this new Genus really likes mountains so he names the species he discovers Mountianus peruensis, because he happened to find it in Peru. So now our Pincer Beetle's name would be called Mountianus newus, because the guy who origionally named it still has 'priority', but he got the Genus wrong, so the first person to correctly name/describe the Genus will lend his name to this beetle too.
Another complication is that sometimes scientists later discover that what they thought were different species are really the same. Let's take an easy example of how this could happen. I think most people are familiar with the North American bird called the cardinal. If you didn't know better, one might think that the males and females are 2 different species. Their coloration is quite different. I do not know the history of cardinal taxonomy, but the person who origionally desbribed and named it could easily have thought they were 2 different species. If that happened, the first published description would be the correct scientific name and the second would be considered a synonym.
If you haven't fallen asleep yet, let's talk about Potamotrygon hystrix. This species was first described in 1834, quite a while ago. I have thus far not been able to find out of the type specimen exists or get a copy of the origional publication, but you can find a summary in the Check list of the freshwater fishes of South and Central America which you can find here: http://books.google.com/books?hl=en...ts=m6BZyR1rUO&sig=Glu4We7nOYoxLC0pB-pfpcXZczg . Summary for P hystrix is on page 24.
As you can see, this species was origionally called Trygon hystrix. It's range is the Parana-Paraguay River basin, with some question on which contries it's range includes, but Brazil is definetly not on the list. It's not even in the Amazon basin! Now, there is some controversy surronding this still, so things could still change (and often do in taxonomy) but right now this is what is accepted by the scientific community.
The ray that the hobby/aquarium trade calls 'true hystrix' (can someone please post a picture of this fish on this thread for people to see?) is found in the Amazon in the Rio Negro in Brazil. I find it highly unlikely that it is the same species. The riiver basins are no where near each other. http://en.wikipedia.org/wiki/Paraná_River The scientists at the symposium in Chicago said it was an undescribed species.
Hope everyone doesn't have a headache! If you got this far, thanks for reading.
E
