Frontosa species discussion

[David R]

Ryan I appreciate that its not just a matter of inventing new species to create sales, I was more suggesting that hobbyists/sellers are more likely to embrace the splitters ideas than the lumpers as it better suits the,.

When you say 'lack of geographical isolation' I assumming the migratory habits of this fish are factored into some of the theories and opinions of this 'heady selection' of experts being quoted in this thread.

As a deeper water fish does that make them greater travelers?

Behavioural difference is sited, what do we know about seasonal or lifetime migration of these fish or lack of it?

By lack of geographic isolation, I mean that the fish are essentially in the same body of water (albeit often separates by many many miles of open space), not isolated in separate likes or rivers, or even separated by some other impassable obstruction like a large waterfall. I have no idea just how far apart the different species are or what their range/migratory habits are, and I am aware that open water can make them seem to be just as isolated. I just feel that Konnings arguments have valid points, if the lake level dropped by 50 metres would they still all be isolated?

Do the terms 'distinct regional varieties' and 'lack of geographical isolation' in the same sentence lead to a logical conclusion?

Going by the heated debates over the names of 'distinct regional varieties' of lake malawi fish that have a 'lack of geographic isolation' then some people would obviously think they do..

I'd be more interested to see why / what is Konning's theory is behind a monotypic genus.

Basically what I said before; that the differences aren't great enough to warrant splitting at species level, and the fact that with such a long history in the lake (including times when they would have been split into 3 separate lakes) that distinctly different species haven't developed as they have with other genera endemic to the lake.

[phoenix44]

The term geographic isolation is ambiguous in that it does not refer to a span of distance as a minimum requirement

A friend of mine is a population geneticist currently doing her PHD up in Auckland. She has given me the following example -

My favourite example of geographic isolation is the Wallace line- this is the line through the islands between Australia and Asia where the animals of those lands do not cross to the other side. It is really amazing because Sulawesi will contain only australian insects, birds and marsupials, where Borneo- just 35 km across the ocean only contains Asian ones- they are so close but yet almost no species cross this line- where previously they must of travelled even further than that to get to these islands from Australia.

It is thus possible for populations to exist in the same area, in close proximity, and yet be geographically isolated. Our native geckos here often live in a tiny amount of space for the entirety of their lives.

[firenzenz]

"Recently therehas been considerable taxonomix revision done to this genus, which was once thought to be monotypic. We now know that there are no fewer than two valid species, with several more nominal species under investigation".

So assuming we hold with this information as being sound in its methodology, then, is not this debate on where on the time line you determine variants becomes new species, and how much taxonomix difference is needed to support the above statement ?

A tenuous link perhaps-

The yellow dots show the distribution of the Stuartgranti species. The interesting thing with them is that the wide array of colouration can be tracked in a graduation from on location to the adjorning one.

eg. the subtle difference between the reddish bodies of Ngar-Mdoka-Chilumba in the north to the mainly yellow bodies of maleri, chipoka in the Sth.

The red,green,white, and pink dots designate species like Jacobfriebergi, chitande where there is wide distribution with locational variances that have no real pattern to development.

Each black dot indicates a individual species specific to one location.

What is interesting is that many of these species are often involved in discussion on whether or not they should be included in the Stuartgranti group, mainly on the merits of the sort of differences in the Front case.

Here again it would seem that an integral part of the equation is time.

PS- my dot are completely out of scale with the spots the indicate on the 580km long lake, so dots right beside each other could be miles apart in reality.

Some of the black and yellow dots however are in the same place and are seperated only by depth.

[David R]

You're not wrong P44, but it is also possible for a single species to have a large distribution over an area with plenty of "geographic isolation" between populations. Look at Homo sapiens for example....

[Aquila]

Might be better to classify them as subspecies.

Just putting it out there, but I don't know anything about Frontosas.