7787

• UCREFRP Catalog Number: 7787
• Author: Desert Fishes Council.
• Title: Proceedings of the Desert Fishes Council Volume XXV, 1993 Annual Symposium.
• USFW Year: 1993.
• USFW - Doc Type: D. A. Hendrickson, ed. November, 10 -14.
• Copyright Material: NO

PROCEEDINGS OF THE DESERT FISHES COUNCIL 1993 - VOLUME XXV
1 1 UBBS, C. Department of Zoology, The Uniwmity of Texas at Austin, Austin, TX 78712
The continuing saga of Gambusia cannibalism
La continuaci6n del cuento sobre canibalismo en Gambusia
KEYWORDS: cannibalism; predation; mosquitofish; Pecos gambusia; largespring gambusia; Texas
CLAVES: Canibalismo; Predaci6n; Pez mosquito; Pecos gambusia; largespring gambusia; Texas
ABSTRACT
The basic premises of the prior reports are retained: 1) Gambusia females eat many more babies than do
Gambusia males. 2) Gambusia nobilis and relatives are more predaceous than Gambusia aff nis and relatives. 3)
Gambusia affinis populations vary widely in cannibalism with some being almost as predaceous as G. nobilis and
others scarcely eating babies. 4) Gambusia nobilis and relatives have heavier birth weights than G. affnis and
relatives. 5) Gambusia affinis birth weights are highly variable. 6) Gambusia nobilis seems to vary in predation and
birth weights as does G. affinis, but Gambusia geiseri seems to be consistent among populations. The other four
species have only one population studied; thus no population variation is known.
RESUMEN
La premsea basica de los reportes anteriores ha sido retenido: 1) hembras de Gambusia comen macho mas crias
que los Gambusia machos. 2) Gambusia nobilis y parientes son mas depredadores que Gambusia affinis y parientes.
3) Las poblaciones de Gambusia affinis varian ampliamente en su canibalismo con algunos cast tan depredadores
como G. nobilis mientras otros escasamente comen crias. 4) Gambusia nobilis y parientes tienen mas peso a] nacer
que G. aff nis y parientes. 5) Los pesos al nacer de Gambusia affinis son altamente variables. 6) Gambusia nobilis
parece variar en depredaci6n y peso al nacer como sucede en G. aff nis, pero Gambusia geiseri parece ser
consistente entre sus poblaciones. Las otras cuatro especies tienen solamente una poblaci6n estudiada; por to tanto
la variati6n de ]a poblaci6n no se conoce.
ESPINoSA r • f R. ; BURGOS L., M.A. 1.61uto de Biologfa, UNAM, Ikpanamento de Zoologia
Status of the fishes and other vertebrates from Aguamilpa, Nayarit, Mdxico
Estado actual, de los peces y otros vertebrados de Aguamilpa, Nayarit, M6xico
KEYWORDS: Peces; Fishes; Huaynamota-Santiago; Nayarit; impacto ambiental; environmental impact; dams; M6xico
ABSTRACT
During construction of the hydroelectric Aguamilpa dam, seven samples in the influence zone were made, with
the objective of evaluating the damage to the biota when the dam was completely full. The vertebrate fauna in the
rivers Huaynamota and Santiago in Nayarit was sampled over 14 months. This presentation focuses on the fishes
as well as recommendations to mitigate the impact of the dam.
RESUMEN
Con motivo de la construcc16n de la Presa Hidroelectrica de Aguamilpa, se realizaron siete muestreos en 1a
zona de influeneia con el fin de. evaluar los dahos que se produeiran a la biota al llenarse el embalse. Durante 14
meses se muestre6 a los vertebrados en los rios Huaynamota y Santiago en el estado de Nayarit. Se presentan los
resultados de dichos registros, con enfasis en el grupo de peces,asi como las medidas recomendadas para mitigar
el impacto causado por la construcci6n de esta obra.
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