Deltense, fallax and Book of Face
Deltense, fallax and Book of Face

Is there anybody in Nigeria or Cameroon On Facebook who has caught these fish?
From the Killi Data FAQ, Q15:
Q(15): What is your opinion on Fp. gularis and Fp.deltaensis? Should they be separate sp. and if so how would you separate them? (Tim Addis, January 2003)

A: Well, this is an uneasy question, not because this is difficult to answer, but because data are insufficient for a perfect answer. Fp. gularis and deltaensis are today well known, well described with precise type localities, distant by about 80 km (Agberi, southern Nigeria, 5.233N 6.383E and ca. 200 yards south of road Sapele-Benin to Warri in western Nigeria delta, Midwestern State, Nigeria, 5.820N 5.770E, respectively), of course. They can be separated by the male color pattern: deltaensis is a yellow phase with a red median line on sides and gularis is a blue phase with very few red spots scattered on sides (Boulenger's description), to many spots and even broken red blotches more or less along mid sides. Whereas deltaensis is only known from a few localities, gularis is known from many locations in western Nigeria and Bénin. No study has been performed since Scheel and no collecting trip has recorded samples since many years, except one. That important collection, reported by Wildekamp (1995), records deltaensis from nearby the type locality of gularis. In addition, crossings between the two are fertile beyond the third generation in aquarium.

These observations may legitimately induce the conclusion that the 2 names correspond to the same species and that deltaensis is a color variation and a junior synonym of gularis, as Wildekamp has proposed. A respectable move.

However, in Killi-Data, conservatism prevails in order to minimize the risk of inappropriate changes and deltaensis is provisionally and cautiously kept valid for 4 reasons: first, gularis from its type locality and according to Boulenger's description (very few spots in male) is unknown live; second, it is not known if the few locations of deltaensis corresponds to a vicariant distribution or to a sympatric pocket distribution within the wider range of gularis; it is not known, either, if the probable sympatric occurrence of the 2 around Agberi is the rule or an accident within the Niger delta which is known as a very complex region for Killifish, maybe because of the past occurrence of an epicontinental sea there; third, it is not known if the genetics of the type population of Agberi are identical to those of the type locality of deltaensis and detailed molecular studies have not been performed over the entire range (preliminary reports show that both species are DNA-distant); fourth, the case deltaensis/gularis should be viewed with a wider point of view, i.e. including fallax Ahl and fallax sensu Seegers (with a publication in preparation from BMNH samples). All in all, very little is known on these fishes and on that region of Nigeria, probably one of the most important for Killifish in terms of speciation. Political instability, only, explains that poor situation. Let's be patient. (Jean Huber, finalized January 2003).

Here's me, still being patient. I list DEL as a species too but I don't think it really is.

Now here's a question, any of these places where DEL and FAL are found, is there anybody there on Facebook?

Because Huber and I disagree on this, his model is to charge access to information, use the money to send people there to collect specimens then evaluate the, back in France.

That will *work* but it's slow. How slow? See above.

Now, what I've always maintained is that it's possible to crowd source this stuff and I have to admit invention on the word "crowd sourcing" has done more to help here than anything. Of course this has worked less well (so far) than Huber's method, but I'm not giving up on the idea ;-)

So, I can not say that this sort of thing will replace ichthyological explorations but do maintain there is a subclass of information that can be obtained in this manner and this example a question about the range of DEL as it grades into FAL (or does not!) could I would think, be easily done by poeple with Facebook on phones taking pictures of ditch fish.

The numbers change this way too, the cost to send somebody to Say, Cameroon to collect for a week or a month costs thousands. What if somebody sent some guy near the biotope of DEL tens, not thousands of dollars? You're paying the guy directly, who either way was gonna be the one hopping in that stream and handing a net to some guy from Belgium or something ;-) Why not just incent him to take photos. That way the premium for paying all those thousands is the actual live (or preserved) specimen but the information (Is this fish found outside the terra typica for DEL) because it lacks tangible form can be had fee or at a small fraction of the usual cost.

So, dear Jean, I'm patient, but not immortal. We gotta do better than this and this might be one way to do that.

VRx Copyright 2017
VRx Network Services, Inc.