Taxonomy issues
Taxonomy issues

Huber: "When Seegers in 1988 erected elberti as a separate species (different from bualanum), he did it because he thought that the morphology of the type of bualanum was different from what should be expected from a member of the subgenus Kathetys.

Here are Seegers comments: ". (v) Panchax bualanus AHL, 1924 most probably is a valid species, but it seems, that this species is not identical with the species bearing this name from 1968 up to now."
Anschrift des Verfassers: LOTHAR SEEGERS, GrenzstraDe 47b, D-4220 Dinslaken
Remarks on the Collection of Cyprinodontiformes (Pisces : Teleostei) of the Zoological Museum, Berlin. I. The Genera Aphyosemion Myers, 1924 and Fundulosoma Ahl, 1924. Part 1
Mitt. Zool. Mus. Berl. 62 (1986) 2, 303-321 19. 9. 1986

That's it, that's the whole comment. Not exactly a compelling argument based on the scientific evidence.

But, in "Huber, J.H. 1998. Miscellaneous notes on some systematic difficulties regarding old world cyprinodonts, JAKA 31 (1) : 3-17" Huber has re-examined the type, and partly based on the internal morphology (x-rays), he found that the types of elberti and bualanum are almost certainly the same. The differences that Seegers found, seem to be caused by the bad state of the bualanum type (missing fin rays, compressed body - actually folded in half etc.)

So Huber reerected the bualanum name, with elberti as a synonym. This is still the status in his Killidata 2000."

Since this is the latest scientific revision, it's the bualanum name that is currently valid."

As of 2014 Catalog of Fishes lists: bualanus, Panchax Ahl [E.] 1924:54 [Zoologischer Anzeiger v. 60 (nos 1/2) (art. 4); ref. 76] Buala [now Bouala, 6°42'N, 15°58'E], Cameroon [now Central African Republic]. Holotype (unique): ZMB 21947 (poor condition). Type catalog: Paepke & Seegers 1986:164 [ref. 19981]. Types mentioned: Paepke 1995:94 [ref. 21847]. •Valid as Aphyosemion bualanum (Ahl 1924) -- (Wildekamp et al. 1986:202 [ref. 6198], Seegers 1988:56 [ref. 19980], Lévèque et al. 1991:144 [ref. 31367], Romand in Lévêque et al. 1992:602 [ref. 21590], Wildekamp 1993:96 [ref. 26378], Huber 1998:5 [ref. 23446] with comments, Lazara 2001:13 [ref. 25711]). Current status: Valid as Aphyosemion bualanum (Ahl 1924). Nothobranchiidae. Distribution: West-central Africa. Habitat: freshwater.

elberti, Panchax Ahl [E.] 1924:309 [Zoologischer Anzeiger v. 60 (nos 11/12); ref. 15436] Jade Plateau, Cameroon. Lectotype: ZMB 21940. Paralectotypes: ZMB 31552 [ex ZMB 21940] (2). Type catalog: Paepke & Seegers 1986:165 [ref. 19981]. Types mentioned: Paepke 1995:94 [ref. 21847]. Lectotype designated by Seegers in Paepke & Seegers 1986:165 [ref. 19981]. •Synonym of Aphyosemion bualanum (Ahl 1924) -- (Wildekamp et al. 1986:203 [ref. 6198], Romand in Lévêque et al. 1992:602 [ref. 21590], Huber 1998:3 [ref. 23446]). •Valid as Aphyosemion elberti (Ahl 1924), subspecies elberti (Ahl 1924) -- (Lazara 2001:18 [ref. 25711]). •Valid as Aphyosemion elberti (Ahl 1924) -- (Seegers 1988:14 [ref. 19980], Wildekamp 1993:145 [ref. 26378], van der Zee et al. 2007:177 [ref. 30034], Agnèse et al. 2013:520 [ref. 32730]). Current status: Valid as Aphyosemion elberti (Ahl 1924). Nothobranchiidae. Distribution: West-central Africa. Habitat: freshwater.

Notes on ELB

1) 177 [ref. 30034], Agnèse et al. 2013:520 [ref. 32730]
This reference to ELB is specious; it merely lists the fish as an outlier and is not meaningful to the taxonomy of ELB.

2) 145 [ref. 26378], van der Zee et al. 2007
Van der Zee (pers. comms.) claims the fish is known in Europe as BUA and has examined the type and confirmed it is in bad condition and compressed and that ELB is from the type location of BUA. They're both Ahl collections. Given how sloppy Ahl was and the profound diversity in the morphotype and the numerous expeditions in he area it seems infinitely more likely he had two different populations (at best) from the area rather than anything actually different from BUA.

The type for BUA would have to have its osteological metrics compared with the type for ELB, if the fish is actually different it will almost certainly show up there. If it is not different then ELB is a junior synonym to BUA. If it not possible to tell the two apart then is has not been proved ELB is any different than BUA and the species remains BUA. Only when it can be shown ELB actually exists and is in any way different from BUA can ELB be considered a valid taxon.

Another way would be to return to Bouala and do a gain additional material to supplement the BUA type; had Seegers been able to using it in any meaningful way chances are very high he would have found it to be the same and would not have made the decision to resurrect what is probably a junior synonym in (Seegers 1988:14 [ref. 19980]).

But given the amount of work and the high probably it's just another form of BUA and especially given the very low quality of Ahl's Work, the chance of ELB actually being a unique species are near zero and I'm entirely comfortable assigning this fish solely to BUA. Do we know for certain? No. Is it worth the effort to verify this? Yes, but every other taxonomic problem in Cyprinodontidae is probably more important than one of Ahl's famous taxonomic goose chases.

If somebody can show Ahl's ELB fish is dissimilar from the BUA from Boula then at that time and that time only can ELB be considered a valid species in my opinion.

Until then I consider ELB nomen dubium.

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Richard J. Sexton