Revision of the Pseudotropheus elongatus species group

[DRE]

A Revision of the Pseudotropheus elongatus species group (Teleostei: Cichlidae) With Description of a New Genus and Seven New Species
S. Li, A.F. Koningsand JR. Stauffer
Zootaxa 4168 (2): 353-381, 2016
http://www.mapress.com/j/zt/article/vie ... a.4168.2.9

New genus:
Chindongo Li et al., 2016
Type species:
Chindongo bellicosus Li et al., 2016

New species:
Cynotilapia chilundu Li et al., 2016
Metriaclima flavicauda Li et al., 2016
Metriaclima usisyae Li et al., 2016
Tropheops kumwera Li et al., 2016
Tropheops biriwira Li et al., 2016
Tropheops mtambokuda Li et al., 2016

Abstract

Lake Malaŵi is known for its endemic haplochromine species flock, most notably the rock-dwelling cichlids known as mbuna. The group of mbuna referred to as the Pseudotropheus elongatus species group is currently comprised of Metriaclima spp., Tropheops spp., Cynotilapia spp., and Pseudotropheus spp. In this study, Chindongo, a new genus with the type species C. bellicosus, is described for additional species in this group. Chindongo is distinguished from other mbuna genera by 1) the presence of bicuspid teeth in the anterior portion of the outer row of both upper and lower jaw; 2) a moderately to steeply sloped vomer with a narrow rostral tip which makes an angle of between 53° and 68° with the parasphenoid; 3) a small mouth with the lower jaw slightly shorter than the upper; 4) a broad anterior dentigerous area on both premaxilla and dentary with three or more rows of teeth (usually 5–6 rows); 5) a flank melanin pattern consisting of vertical bars without horizontal elements at any stage of development. Chindongo bellicosus is distinguished by its color pattern and shallower body from the other species which we have transferred to Chindongo. We also describe six new elongate mbuna species and place them into three available genera, they include: Metriaclima flavicauda, M. usisyae, Tropheops kumwera, T. biriwera, T. kamtambo, and Cynotilapia chilundu.

[DRE]

Would be interesting to know which of the undescribed that now got a name.

[Philippe Burnel]

The best is to wait for the complete PDF file

[Juan Artigas]

Cynotilapia sp. 'elongatus taiwan' [p. 18] -> Cynotilapia chilundu
Metriaclima sp. 'elongatus usisya' [p. 7] -> Metriaclima usisyae
Metriaclima sp. 'elongatus yellow tail' [p. 4] -> Metriaclima flavicauda
Pseudotropheus sp. 'elongatus aggressive' [p. 22] -> Chindongo bellicosus
Tropheops sp. 'elongatus boadzulu' [p. 9] -> Tropheops kumwera
Tropheops sp. 'elongatus green back' [p. 13] -> Tropheops biriwira
Tropheops sp. 'elongatus reef' [p. 15] -> Tropheops kamtambo

http://www.cichlidae.com/reference.php?id=7492

[DRE]

Thanks!!

[Philippe Burnel]

Just a quick look to the pdf... I feel strange that, today, a new genus is described without any genetic study

Philippe

[Juan Artigas]

And with such a weak diagnosis. I thought it would have be wiser to merge than to split but such are the times

[Dave Schumacher]

I haven't seen the pdf yet, but I am glad to see someone tackling the mess that is Pseudotropheus. It's been used as a catch all genus for any mbuna that didn't fit elsewhere. With williamsi being the type, it was hard to imagine the newly described bellicosus would remain there forever.

[Philippe Burnel]

Of course many of the spp previously includeed in Pseudotropheus are not Pseudotropheus S.S..
But the description of a new genus based only on morphology and without any genetic study is all but a good way (not sure that my english is good)
And, as Juan wrote it, " with such a weak diagnosis".

A first step, but not the last one.
Probabbly much more difficult to resolve that the one with central american cihlids.

[Rico Morgenstern]

The interrelationships within the L. Malawi species flocks are certainly far too complex and too close to get a useful molecular phylogeny, at least with the available methods. This may change in the future, but at present there is no other choice than delimitation of genera by morphology only. And the diagnosis is surely not weaker than that of most other genera of Mbuna or indeed that of the Mbuna as a whole. I'm not overly familiar with that particular group of cichlids but I think this approach is much better than falling back into times where we had a large catch-all genus, with some specialized "offshoots" recognized as separate genera.

[Bojan Dolenc]

Note: Tropheops kamtambo Li et al., 2016 was named T. mtambokuda in Li’s Dissertation of 2014?

► A Revision of the Pseudotropheus Elongatus Group with a Description of a New Genus Chindongo and Seven New Species. Shan Li
2014. Book

Lake malawi is an African lake surrounded by Malawi, Tanzania, and Mozambique, and is known for its endemic haplochromine species flock, most notably, the rock-dwelling cichlids known as mbuna. Mbuna include genera such as Metriaclima, Tropheops, Cynotilapia, and Pseudotropheus. Cynotilapia is one of the most primitive group of mbuna, and the species of Cynotilapia differ in one main anatomical characteristic from those of Metriaclima, Tropheops, and Pseudotropheus by possessing widely spaced conical teeth in the outer jaws while the others all have bicuspid teeth. Metriaclima and Tropheops are genera split from Pseudotropheus recently on the basis of their different feeding behavior and several morphological characteristics including the angle of the vomer and tooth structures. A number of unique populations of elongate mbuna in Metriaclima, Tropheops, and Cynotilapia are not formally described or grouped into the Pseudotropheus elongates complex. The purpose of this study is to describe several members of this complex that belong to Metriaclima, Tropheops, Cynotilapia, or Chindongo, a new genus. Morphological and meristic data were collected for 255 specimens from 14 collections from Lake Malawi. Morphological differences were analyzed using a sheared principal component analysis (SPCA) of the morphometric data and a principal component analysis (PCA) of the meristic data. Different color forms and feeding behaviors were also investigated in this study. This study resulted in the description of a new genus, Chindongo, with its type species C. bellicosus, and six new species belonging to the existing genera Metriaclima, Tropheops, and Cynotilapia: M. flavicauda, M. usisyae, T. kumwera, T. biriwira, T. mtambokuda, and C. chilundu. The new genus and species were distinguished and described based on color patterns, morphometric, meristic, and on ecological differences. They were also compared with, and distinguished from nearby populations having similar pigmentation patterns or similar ecological niches. An artificial dichotomous key is provided to each genus.

P.s. Because of unresolved status of Metriaclima, which is treated by several authors as synonym of Maylandia, both new Metriaclima species might be placed in Maylandia.

[Dave Schumacher]

Ad was kind enough to send me the pdf of the paper. While bellicosus is the type of Chindongo, it is not a monotypic genus. From the paper:

"In addition to the newly described C. bellicosus, we assign the following species, which were previously in Pseudotropheus, to Chindongo: C. ater, C. cyaneus, C. demasoni, C. elongatus, C. flavus, C. heteropictus, C. longior, C. minutus, C. saulosi, and C. socolofi."

[DRE]

Aha so all of those also belongs to the new genus, that was interesting.

btw, if you could share pdf with me, I'd be very happy.

///David

[Juan Artigas]

Thanks Dave! My bad, I don't know how I missed that. I still believe the diagnosis is weak but now it make a lot more sense and it was certainly expected. I was baffled trying to discern why no other species were not placed in the same genus

[Dave Schumacher]

I had read these posts before I had a chance to see the pdf, and also thought that it was strange for bellicosus to get it's own genus. They didn't seem unique enough! Definitely makes more sense with the other species included. I would assume the other related undescribed species would need to be included as well, such as P. sp. "elongatus spot", and sp. "ndumbi gold".

Hopefully some of the other species groups like elegans/sp. "acei", perspicax/sp. "polit", johanni/perileucos/cyaneorhabdos, etc will get their own generas in the future. There are many more that get lumped in Pseudotropheus simply because they have nowhere else to go at the moment.

FYI, Ad mentioned that he is in Italy right now when he sent me the pdf. If anyone would like a copy, PM me your email address, and I'd be happy to forward it so that he doesn't have to while on vacation!