Proceedings of the Desert Fishes Council 2000

PROCEEDINGS OF THE DESERT FISHES COUNCIL - VOLUME XXX1I (2000 SYMPOSIUM) – PUBLISHED NOVEMBER 13, 2001
more attracted to the traps that lacked bait (p < 0.01). Perhaps these small minnows have a bigger brain and a
smaller nose than we thought.
RESUMEN
Carnada y cambio: atracción de carpas tui a trampas cebadas
Llevamos a cabo un experimento en el canal McNally, una vía de distribución del Río Owens, tres millas
[4.8 km] al norte del Museo Laws, Condado de Inyo, California. El proyecto era parte de una clase de Biología
Avanzada de escuela preparatoria. El objetivo era hallar una forma más efectiva de atrapar carpas tui híbridas
para conocer más acerca de la nativa carpa tui del Owens, Gila bicolor snyderi. Otros métodos de captura, como
la electropesca, han sido objeto de debate por la posibilidad de causar heridas a los peces. Intentamos atraer a los
peces con todo, desde chocolate hasta alimento para gatos. Pensábamos que se sentirían atraídos por los aromas
de nuestras preparaciones, y sin embargo encontramos que fueron más eficientes las trampas sin carnada (p <
0.01). Tal vez estos pequeños peces tienen un cerebro más grande y una nariz más pequeña de lo que
pensábamos.
Modde, T 1 ; Kitcheyan, DC 1 ; Bowen, Z 2
(1-U.S. Fish & Wildlife Service; 2-U.S. Geological Survey)
Temporal and spatial use of a spawning site in the middle Green River by razorback
sucker
ABSTRACT
Sedimentation on spawning sites in the middle Green River has been mentioned as a potential impediment
to the reproductive success of razorback sucker, Xyrauchen texanus. Recent studies indicate that fine sediment
moves across the Escalante spawning bar in the middle Green River. Description of the timing and distribution
of fish on the spawning bar are instrumental in determining whether sedimentation patterns impact hatching
success. In an effort to address the relationship of spawning activity to sedimentation patterns, we monitored the
timing and distribution of razorbackes suckers on the Escalante spawning bar during the spring 2000 spawning
season. Razorback suckers were captured with electrofishing boats on the Escalante spawning area (i.e.
Razorback bar) in the middle Green River from 1 May through 17 May 2000. Radio transmitters were externally
attached to the dorsal keel of nine fish captured on the spawning bar. Two fish were of wild origin and seven
were reared at the Ouray National Fish Hatchery and stocked in previous years. Eight of the nine fish were
males and one was a female (hatchery origin). During a two-week period, specific locations of razorback suckers
were monitored during four individual 24-hr periods. During each monitoring period, specific locations of fish
were triangulated every hour. In addition, a telemetry logging station continually monitored fish presence on the
spawning bar. Six fish were located on the spawning bar and five fish were detected on the bar for at least five
days. Fish presence on the bar was related to both temperature and discharge. The distribution and time fish
spent on the bar was compared between diurnal and nocturnal hours. Fish presence on the spawning bar
occurred in a very localized area with other apparent useable spawning areas not utilized. The duration of time
fish were found on the spawning bar was underestimated using electrofishing data only.
RESUMEN
Utilización temporal y espacial por el matalote jorobado de un sitio de desove en la parte
media del Río Green
Se ha mencionado que la sedimentación sobre los sitios de desove en la parte media del Río Green es un
problema potencial para el éxito reproductivo del matalote jorobado, Xyrauchen texanus. En estudios recientes
se encontró que los sedimentos finos son transportados a través de la barra de desove Escalante, en dicha parte
del Río Green. Para determinar si los patrones de sedimentación influyen en el éxito reproductivo, es
imperativo describir la distribución espacio-temporal de los matalotes en dicha barra. Con el objeto de
averiguar la posible relación entre la actividad de desove y los patrones de sedimentación, durante la temporada
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