7043

• UCREFRP Catalog Number: 7043
• Author: Desert Fishes Council ‎(Edwin Pister, e.
• Title: Proceedings of the Desert Fishes Council Volumes XVI-XVIII
• USFW Year: 1987.
• USFW - Doc Type: The Sixteenth - Eighteenth Annual Symposia.
• Copyright Material: NO

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The catfishes, Ictaluridae, with two species in two genera,
present another level of reproductive behavior. The male guards
and fans the eggs, and he shepherds the baby fish. Sometimes the
female remains and assists the male in caring for the young,
producing a monogamous pair.
Best known for monogamy and biparental care, however, is the
family Cichlidae. Interestingly, the common cichlid in Cuatro
Cienegas may prove to be a maternal caretaking species, an
unusual state of affairs for fishes in general. This is one of
the most ubiquitous fishes in the basin, and its mating system
may well differ among the springs.
The Poecillidae is treated last because of its advanced care
of young. The female carries them in her ovary where they develop
out of harm's way. The mating system is not known in any detail,
but fishes in this family are polygynous.
Thus we see that the situation at Cuatro Cienegas offers
unparalleled opportunities. It is a complex of natural
experiments such that the judicious investigator can pick and
choose springs appropriate to the hypothesis in question.
Because of the shallow clear waters, benign experiments can then
be carried out to refine the study.
Now I would like to digress to address briefly two issues.
One is the re-establishment of populations where they once
existed but have become extinct. The other is the issue of
extinction in the larger context.
According to Sewell Wright it is virtually axiomatic that
evolutionary change is hastened by small population size. When a
small founder population is introduced into a spring, as has