cichlids look nearly identical.

[Johannes Visser]

http://users.aber.ac.uk/mkm5/rift_valley_cichlids.htm

interesting !!

Lynn :bounce:

[kylefish02]

those are crap drawings moori and fronny's look nothing alike same goes for auratus and thos julidichromis.those pix have been changed a little to get u t think they look alike

[herefishiefishie]

Nice one Lynn. Part of the article I don't agree with in the link. I will go by what I have last read, referenced too.

I came across that picture in a George W Barlow book.

"The Cichlid Fishes. Natures Grand Experiment in Evolution."

That picture originally comes from Axel Meyer.

"Trends in Ecology & Evolution"

Phylogentic relationships & evolutionary process in east African cichlid fishes.

The figure in George Barlows, has this under the picture.

FIGURE 12.2 The independently evolved cichlids in Lake Tanganyika{left} & Lake Malawi{right} have converged on remarkably similar forms.{courtesy of Axel Meyer}

The chapter in this book goes for 30 pages. Dam good read, very interesting... try to brake down too a few points.

Lake Tangy 6 Million years old

Lake Malawi 1-2 Million years old

Lake Victoria 12400 years old. It was dry for a few thousand years before that.

Lake Malawi, made up of mostly haplochromines,{Mbuna, Utaka...} in fact genetic study revealed this stems back to a single lineage. The other few stem back to Tilapiines. Other scientists suggest, the single lineage could be wrong, but all are still haps.

Lake Tangy has 12 different lineages or tribes. 8 of those are found exclusively in Lake Tangy. Haplochromines only make up about 5% of species.

Lake Victoria has 2 tribes, one tilapiines, the other haplochromines. Now Victoria has as many as 500 different species in just 12400 years. The DNA of 14 species of 9 endemic genera was analyzed, the variation among the species was less than within our own species, Homo sapiens.

Anyone that has kept Victorain cichlids, will have noted they are all very similar. They may have evolved different shape heads, but their bodies have remained relatively unaltered.

Yet Lake Malawi is mostly Haps too & look at the differences. Both head shape & body shape.

Anyway, a point you can take from the link, is think about this. Nothing else in Lake Malawi looks like a C. moorii, same can be said for Fronnies in Lake Tangy. Yet they do look similar & they are in different Lakes.

Thats the biggy, all these fish in the srticle look similar, are in different lakes, the pics are there to show similarities.

This theory is that once the lakes were joined to form one very large lake which had connections with the surrounding river systems. This meant that more than one species of cichlid, as well as many other types of fish, had access to the body of water. However over time the lake began to change due to the geology of the area, the Rift Valley is situated on a vast fault line which is geologically active. So over time many smaller lakes formed and within each lake a collection of fishes were trapped. To begin with each of the species within the lakes were the same but over time they needed to change to suit their surroundings. Due to the fact that the lakes are very similar in habitats some of the cichlids took a similar evolutionary path. In the image below you can see how although the lakes are miles apart the cichlids look nearly identical.

How can that be true?

If Lake Tangy is the oldest, & is made up of all these different lineages, mentioned above & only 5% haps.

If Lake Malawi is mostly Haps only, stem beck to only one line or a few. When you also note that Utakas stem from Haps too.

His pictures in the link, eg; show comparsions of non haps to haps too.

Someone link him George's book.

Frenchy