Type Locality Corydoras Aeneus

CoryfanAad · Post by **CoryfanAad** » 25 Oct 2013, 10:49

Mentioned is Trinidad (West Indies).
Aeneus is found in a great part of South America to my believe and I even have my doubts if so at Trinidad.

Am I wrong?

Cheers Aad

Acanthicus · Post by **Acanthicus** » 25 Oct 2013, 11:01

Hi,

the type locality is in Trinidad, yes. But similar forms are spread over huge parts of SA. The "C. aeneus" from Peru, Brasil and Bolivia etc. are for sure not identical with the real C. aeneus, they only look similar. They will turn out as many different species/forms one day I guess.

CoryfanAad · Post by **CoryfanAad** » 25 Oct 2013, 11:31

Sorry for a stupid question : What exactly is meand by type locality than? I know there are several species (keeping 4 different ones myself) but just don't understand Trinidad being mentioned. Cheers Aad

Tony C · Post by **Tony C** » 25 Oct 2013, 12:53

CoryfanAad wrote:Sorry for a stupid question : What exactly is meand by type locality than? I know there are several species (keeping 4 different ones myself) but just don't understand Trinidad being mentioned. Cheers Aad

The type locality is where the original specimen(s) on which the species description is based was collected.

CoryfanAad · Post by **CoryfanAad** » 25 Oct 2013, 12:58

Ahaa sounds logicall. Thanks Tony. I didn't suspect that this would be at Trinidad, cause Aeneus is found so widespread over SA !!!!
In one way or the other I thought these fish wouldn't be found at an Island hahaha. Thanks again.

Narwhal72 · Post by **Narwhal72** » 25 Oct 2013, 17:07

Are we sure that the type location is not referring to the city of Trinidad in Bolivia? and not the island? Anyone have access to (Gill, 1858) where it was originally described?

Trinidad is very close to the continent so it is quite believable that at periods of lower ocean level they may have been connected. But it would seem odd that a fish with such geographical isolation from the rest of SA would have such a widespread distribution.

Andy

racoll · Post by **racoll** » 25 Oct 2013, 18:05

You can read the description here.

Narwhal72 wrote:Are we sure that the type location is not referring to the city of Trinidad in Bolivia? and not the island?

No, the title of the paper is "Synopsis of the fresh water fishes of the western portion of the island of Trinidad, W. I.".

dw1305 · Post by **dw1305** » 25 Oct 2013, 19:41

Hi all,

Trinidad is very close to the continent so it is quite believable that at periods of lower ocean level they may have been connected.

They were until about 10,00 years ago, bio-geographically Trinidad is part of S. America, not the Caribbean island arc. On a more parochial level it is like the Isle of Wight, not the Azores. That is why Howler Monkeys, as well as Corydoras and Loricariids etc, occur on Trinidad.

There are images from the type locality on the Cat-eLog page (taken by Colin Dunlop?).

cheers Darrel

CoryfanAad · Post by **CoryfanAad** » 25 Oct 2013, 21:06

Thanks all. Quite interesting to me!!!

YouTube · Post by **Jools** » 26 Oct 2013, 09:59

Yeah, it's worth putting out a look at why and how this occurs like it does as (at least I) find this interesting. With apologies to the professionals, here's the vernacular:

So, type locality, as it says in the glossary, is where the individual specimen that was chosen to represent the species (the holotype) came from. With species that have been around for a while, it is interesting to note these are usually where Europeans, and later on North Americans too, came in contact with new rivers. So we see new species beginning to be described from the Caribbean coast and down by Buenos Aires etc. A lot of fishes also were described from fish markets where fishes were brought from upstream. Later on more and more expeditions are mounted and we see an increase of fishes described from further inland. Finally, we get to today where new species turn up anywhere.

However, when one describes a new species you have to compare it to everything else that has been described first to make sure it's not the same as an existing species. This is hard work, and must have been very hard pre-aeroplanes and still difficult pre email/internet. That is because the holotypes are spread out across the globe in whatever museums they ended up in. The papers in which new species are described are (until recently) only distributed in paper form.

So this is why we get synonyms. Imagine someone finds a cory in, let's say, 1880's Argentina, and calls it a new species and gives it a name. Only, say, a hundred years later, someone else looks at this and says, hang on, this is the same species as, for example, Corydoras aeneus (from 1858). So, the newer species becomes a junior synonym. Perhaps the author of the paper of the new species didn't know about the other description, perhaps they couldn't examine it or indeed perhaps they didn't accept it was the same. The clues to this are in the manuscripts and a great deal of rather holistic detective work is also required. In many cases it is mind bogglingly complex.

Meanwhile, I think I can move this issue to resolved.

Jools