Re: Sexing regani

[Mike & Diane Wise <apistowise@bewellnet.com>]

Susanne and Cory Williamson wrote:

> The Apisto books I have paroused (at the LFS- since I can't afford the
> outrageous prices they are charging- min $50) have shown various Apistos
> without showing any decent comparartive anatomy.

This is one of my main complaints with these books. They put the fish in
alphabetical order instead of grouped into similar species grouping. The Linke &
Staeck book, American Cichlids I: Dwarf Cichlids, should retail for $35 - $40. It
is presently the best, using line drawings,  at showing difference between
species. The best book at comparing apistos is Koslowski's Die Buntbarshche der
Neuen Welt - Zwergcichliden. He grouped species by groups and complexes.
Unfortunately it's out of print now and his revised edition won't be out for a
couple of years. I'm looking for a couple of copies of this book if anyone knows
where I can get them.

> What I need is a good well designed dichotomous key for the Apistogramma. Does
> such a thing exist (at least for the described species (or even the common
> ones)?

I know of a couple of people who have tried to do this using cladistic programs
but they came out gibberish. One problem is  that many of the characteristics
needed by the programs to work properly over the nearly 100 known species aren't
know for all of the species. Half of these species are still undescribed and half
of the described species are in need of redescription using modern methods.
Another problem is that there is so much evolutionary convergence in the genus,
as now understood, that many synapomorphic characters are lost in the mish-mash.
Instead of a nice branching cladogram these people got a briar patch of crossing
lines. Römer did an exceptional key for the cacatuoides species-complex. It was
originally published in DATZ, but the ASG did a translation of it in the
ApistoGram (v.14(1&2) #54/55:30-46). I can't think of any other keys that are
useful.

> I don't recall that Linke & Staeck describe the differences between the regani
> sexes (am I wrong).

I thought that the photos showed the obvious difference.

> I have a keen eye for this sort of biological minutia- but I am lacking the
> necessary information to make the call.  Is there a biological paper ( or
> somthing like this) that describes regani in detail.

Yes, the original description goes into detail on the species, as would be
expected. It can be found in a rather hard to get monograph: Kullander, S. O.
1980. A taxonomical study of the genus Apistogramma Regan, with a revision of
Brazilian Species (Teleostei: Percoidei: Cichlidae). Bonner Zoologische
Monographien, Nr. 14. Kullander just mentions that the soft dorsal rays are,
"rounded in smallest, in others pointed, produced in large males, at most to end
of caudal fin." He also mentions, "There is noticeable variation in colouration
between specimens from different collections (= localities). Young fishes tend to
be more yellowish in ground-, colour …".

> I am basically fairly certain that the three reganis that are similar are
> males- but I have a pair of A. borelli in the same tank and the three regani
> have behaviours that are more like the female borelli (in terms of activity as
> well as color markings) I assumed that Apistos would maintain behaviours
> peculiar to each sex across
> species (Bad assumption?).

Yes, especially A. borellii. Compared to other apistos it's one weird character.
The females breeding behavior and brood colors are rather unusual compared to the
average apisto. Females breed more like Nanacara anomala - egg hiders, not
necessarily cave spawners. They even spawn on vertical rocks and leaves, if
shaded and in a quiet locations. The males tend to be more parental than most
other apistos, too. They often take over complete control of a brood after a
couple of weeks, allowing the female to breed again. As most people will attest,
A. borellii is far from shy. This is probably due to something in their natural
habitat - maybe, like Dicrossus filamentosus, due to a paucity of predators. A.
borellii has many unusual features including a lower lateral line without sensory
canals and having no gill rakers (This in a geophagine??? Very atypical!)!

> The one thing that is still clear is that I have no idea- but thanks just the
> same, I appreciate the help- I think these Apistos are very cool!

So have I; for 25 years!

Mike Wise

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