Re: Apistogramma njsseni

[Erik Olson <eriko@wrq.com>]

[Surrendering the keyboard for a moment...]

On Sun, 5 Jan 1997, Corey Geving wrote:

> Hello all.  I have recently acquired a pair of A njsseni
...
> The female is much
> smaller than the male (just over 1 cm); she seems to have a faint
> version of the orange marking on the margin of the caudal fin - is this
> normal, or have I ended up with a juvenile male?  She shows a faint
> black spot at the base of the caudal peduncle but this disappears in
> certain moods. 

The female can have the red/orange margin on the caudal fin, as well as a
black spot on the caudal peduncle, usually they also have a large lateral
spot as well, but a male can have these features as well.  The experts I
have talked to (David Soares and Uwe Romer) say the best way to tell a
female is by black on the ventral fins. 


> At what size do female A njsseni reach sexual maturity?
> I've noticed a lot of territorial behavior between them (with no damage)
> but not what I'd call courtship.  Also, is it better to condition them
> seperately and introduce the male to the female's tank later or will
> they pair off naturally in the same aquarium?

I'm not sure what size your tank is, some breeders I talk to swear by a 20
gallon or bigger, others say 15g and up.  Since we have limited space in
our tank rack, we kept 2 pairs of nijsseni, 1 pair each per 10 gallon
tank. Each 10 gallon tank is heavily planted, with watersprite, java fern,
java moss, and anubias.  As well as bogwood, and an overturned clay pot. 
The males were pretty aggressive toward the females and talking to friends
that have spawned the fish as well they agree.  Theoretically they can be
harem fish, but I haven't played with that one.  Our males would dominate
the females, until she spawned and then she would beat him up.  This cycle
has continued for several spawns.  Now, we have yet to get fry, our pH is
a little to high (6.8) and we have been experimenting with ways to lower
the pH (I hear 5.5 range is the best).  Our water hardness is approx. 30
ppm. Talking to three different spawners of nijsseni we've gotten three
different answers on the best substance to lower pH. 

Our female was probably an inch before she started to spawn.  We feed them
a variety of food, inc, baby brine, frozen blood worms, and flake food. 

For articles on spawning nijsseni there are three off the top of my head
in Buntbarshe Bulletin [BB] (Journal of the American Cichlid Assoc.) #1-by
Schmettkamp BB 120, June 1987 pg 20-21, #2- by Kullander in 1979 rewritten
by J Cardwell BB 147 Dec 1991 pg 6-9.  Also there is an article by Dave
Sanford on spawning nijsseni this month and next month spawning A. 
pandurini in the Greater Seattle Aquarium Society newletter called
Northwest Aquaria (plug, plug).  Aqualog has pictures of both males and
females in Southamerican Ciclids II, and the Dwarf Ciclid book by Linke &
Staeck does as well (if you don't have these you can always sneak a look
at them in your local fish store)  Another side note is that I have seen
the new species A. pandurini come in as contaminants/mislabeled as
nijsseni, perhaps you have some of those. (less likely, but possible,
there the females have a lateral spot that is almost/can be a stripe that
runs down to the ventral surface.  The black under the cheek runs
continously to this spot on the ventral surface, and another breeder says
the way to tell them apart is by the caudal spot-present on nijsseni and
not on pandurini). 

Good luck, they're beautiful fish.  Any other questions feel free to write
back. 

Kathy Knudsen Olson
kk691111@bcm.tmc.edu  

---
Erik D. Olson					         amazingly, at home
eriko@wrq.com