Re: Life-spans and spawnings

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

ALEX PASTOR wrote:

> A couple of months back, Mary Bailey (just love her) wrote in "Practical
> Fishkeeping" that apistos spawn once or twice.  She did not specify if this
> was only in the wild or in an aquarium.

I'm sure she meant in the wild. Most apistos are believed to be annual fish in
the wild. Very few fully adult species are collected in the wild. It is thought
that they spawn a few times and then most are lost to predation. I, too, have a
great respect for what Mary has done for the BCA and the hobby in general.

> Since October she has not spawned.  Has she reached "fish menopause"?  She
> is eating normally still, but she does not look as sleek as before.

She's probably in a resting stage. Angelfish pairs commonly go through this. As
she ages she will continue to breed but probably will have smaller broods. If
healthy, she will breed until she dies.

> What I would like to know is: What is the expected lifespan of these fish if
> they are properly kept and eat a good diet?

Römer did a statistical study on apisto longevity in 23 different species many
years ago. He used 7,532 fish in this study and placed rigorous standards on
which fish were used. All were aquarium bred with known hatching dates. All had
to be at least 9 months old before they could be considered acceptable for the
study. His findings: only 8% survived beyond 24 months of age. Over 75% had died
by 18 months and 33% didn't survive their first year. the longest lived specimens
survived over 76 months.

>From these statistics Römer placed old age in apistos at 24 months.  Old age,
however, doesn't mean that they were infertile. 4 to 5 year old fish in his study
could still successfully breed. Most of the fish over 2 years old were males so
it seems that raising fry takes a lot out of females.

Anyone interested in his study can find it in:

Römer, Uwe.  1991.  Zur Lebenserwartung von Zwergbuntbarschen der Gattung
Apistogramma.  D.C.G.-Info. 22(2): 42-45.

ASG members can get the article and an English translation from me.

Mike Wise

> -------------------------------------------------------------------------
> This is the apistogramma mailing list, apisto@majordomo.pobox.com.
> For instructions on how to subscribe or unsubscribe or get help,
> email apisto-request@majordomo.pobox.com.
> Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!




-------------------------------------------------------------------------
This is the apistogramma mailing list, apisto@majordomo.pobox.com.
For instructions on how to subscribe or unsubscribe or get help,
email apisto-request@majordomo.pobox.com.
Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!