Pseudacanthicus spinosus locality distribution in Cat-eLog

[hotchiliz]

Hi,

I would like to highlight that the locality distribution of this species that is published is too general. Instead of being found in the Amazon itself, the more specific location would be from Cameta - Maraba, Rio Tocantin and also from Rio do Para (Portel) which also consist of Rio Anapu.

I would not have seen or heard any of them that comes from the Orinoco Basin, Venezuela too.

Mingxin

[MatsP]

Do you have a scientific document that describes that, or is this based on some "this is where the fish are captured in aquatic trade"?

The original description is from 1855, so the distribution was probably not quite as detailed in the original description as it is in modern descriptions.

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Mats

[hotchiliz]

here at piranha-info.com
http://www.piranha-info.com/default.php ... d=LNumbers

also from here:
http://l-welse.ig-bssw.org/thread-127.html
http://l-welse.ig-bssw.org/thread-33.html

its states a more detailed locality of both L96 and L160.

[MatsP]

Yes, that describes where those certain L-numbers come from. L-numbers are not the same as a species, an L-number may be a species, or a population that is a geographic variant of a species. We can then argue whether P. spinosus and those L-numbers are the same - that is a point being discussed in the thread in "Speak Easy" with the title "Cross-breeding". But as it stands, the view here is that L096 and L160 and P. spinosus are the same species. That means that the distribution covers ALL of the locations described by the L096, L160 and P. spinosus - and the way that the occurrence data is considered in the Cat-eLog is that "any body of water also means anything flowing into that body of water".

The occurrences of this fish in Fishbase list 5 specimens, but the capture locations leave a fair bit to be desired - one says "Para to Manaus" - well, that's about a third of the length of the Amazon. The only one with a reasonably precise location is "Marajo Island", which in my search appear to be in the Amazon Delta where the river flows into the Atlantic.

What I'm trying to say here is that we do not have much information, and the choices are (this is not a complete list, but some of the most obvious choices):
1. Split L160 and L96 off from P. spinosus.
2. Leave it as it is.
3. Add more specific known locations where these fishes are captured.

Of course, we may also do something of a combination of the above.

And please understand that I'm not saying you are wrong here. It's just that any change to the database should be done for the right reasons - and I don't want us to end up in a situation where a fish out of river X is considered to NOT be the species a scientist would consider it to be, just because we don't list the location in the Cat-eLog.

Finally, I do consider that for breeding purposes, we should keep species that come from the same location together, and separate from others from a different location. This holds true whether these fish are considered one species, two species or 100 species.
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Mats

[Jools]

The type locality is the type locality and that's a fact - so no change need if its correct.

As to distribution, the approach I've taken where this happens with other l-numbers is to state in the distribution entry the locality of each l-number and then go on to say that this is within the wider distribution area of X.

If you wouldn't mind adding this change to that effect Mats, I think we have a plan.

I am pretty happy that both these l-numbers fit within the species description as it stands. If another species was described from the Tocantins then we'd go with that - but I have no reason to believe that will happen.



Jools

[MatsP]

I will make updates as suggested.

Updates now submitted, Jools will have to approve before they become visible on the site. I hope this is acceptable to you.
I think I will also update the occurrence records, so someone searching for fish from, say, Rio Guama, will find P. spinosus as one of the fish from that region.

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Mats

[MatsP]

Occurrence records updated.

I'm very tempted to move this to "Resolved". Anyone objecting to that?

--
Mats

[Jools]

Resolved!

Jools