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Jeanette Carpenter

Publications and source records attributed to Jeanette Carpenter.

4 recordsLinked to original sources

Preliminary testing of the role of exercise and predator recognition for bonytail and razorback sucker

Hatchery-reared juvenile, <25-cm TL (total length), razorback suckers appeared curious and showed no sign of predator avoidance when initially placed with large (>45-cm TL) flathead catfish. Predator-na&iuml;ve juveniles (20- to 25-cm TL) exhibited no discernable preference when provided areas with and without (52 percent and 48 percent, n = 16 observations; 46 percent and 54 percent, n = 20 observations) large flathead catfish. However, once predation occurred, use of predator-free areas nearly doubled in two trials (36 percent and 64 percent, n = 50 observations; 33 percent and 67 percent, n = 12 observations). A more stringent test examining available area indicated predator-savvy razorback suckers used predator-free areas (88 percent, n = 21) illustrating predator avoidance was a learned behavior. Razorback suckers exercised (treatment) in water current (<0.3 m/s) for 10 weeks exhibited greater swimming stamina than unexercised, control fish. When exercised and unexercised razorback suckers were placed together with large predators in 2006, treatment fish had significantly fewer (n = 9, z = 1.69, p = 0.046) mortalities than control fish, suggesting increased stamina improved predator escape skills. Predator/prey tests comparing razorback suckers that had been previously exposed to a predation event with control fish, found treatment fish also had significantly fewer losses than predatorna&iuml;ve fish (p = 0.017). Similar tests exposing predator-savvy and predator-na&iuml;ve bonytail with largemouth bass showed a similar trend; predator-savvy bonytail suffered 38 percent fewer losses than control fish. However, there was not a statistically significant difference between the test groups (p = 0.143) due to small sample size. All exercise and predator exposure trials increased the survival rate of razorback sucker and bonytail compared to untreated counterparts.

Open-File Report↗

Cibola High Levee Pond annual report 2004

This represents the fourth and last annual report of a five year study investigating the early life ecology of the bonytail and razorback sucker at Cibola High Levee Pond. The work in 2004 included: telemetry studies, collection of physical water quality measurements, zooplankton samples, netting fish, the collection of scale samples for aging, predator/prey tank tests and a preliminary analysis of the data base. Juvenile bonytail and razorback suckers were collected this year, demonstrating that natural recruitment occurred for both species. Young from 2004, 2003, and 2002 were all represented in our sample. Unfortunately, we discovered that largemouth bass had also spawned. Approximately 100 young bass were observed during a snorkeling trip in late July. Bass ranged in size from an estimated 5 to 50 cm and were distributed throughout the pond. Attempts to determine the cover preference of 30-cm bonytail met difficulties. Spawning occurred a month earlier than previous years due to an unseasonably warm spring. The combination of warmer temperatures and the vigors of spawning attributed to higher stress and associated mortality of study fish. We replicated our procedures under hatchery conditions on the chance that transmitter attachment was at fault but we experienced similar post-release mortality, including the control fish. This supports the long held contention that bonytail are extremely fragile during and after spawning. In the predator-prey tests, young of every species tested ate razorback sucker larvae. The most aggressive predators tested in 2004 (n = 8 species) were young of the year green sunfish, channel catfish, and common carp. Bullfrog tadpoles and red swamp crayfish also ate razorback sucker larvae and eggs, showing predation is not limited to predatory fish. This work illustrates that early life stages are quite vulnerable to small predators that have easy access to shallow nursery habitats. Remaining work will be finished this coming summer and a final report describing CHLP and the ecology of these fish will be completed by the end of 2005. We offer our assistance to the Fish and Wildlife Service in the pond&rsquo;s renovation and support for the creation of additional refuge ponds. Funding for this work ends September 2005.

Cibola High Levee Pond↗

Macrohabitat of Sonora Chub ( Gila ditaenia ) in Sycamore Creek, Santa Cruz County, Arizona

Physical characteristics and persistence of macrohabitat used by different life stages of Sonora chub ( Gila ditaenia ) were determined by repeatedly measuring distinct reaches in Sycamore Creek, Santa Cruz County, Arizona, in 1990 and 1991. At the beginning of summer drought, habitats occupied by adult Sonora chub were deeper and larger than areas with only immature fish and unoccupied areas. The medians of maximum depth were 47.0 cm (1990) and 39.7 cm (1991) for habitats with adults, 21.3 cm (1990) and 22.9 cm (1991) for habitats with only immature fish, and 14.6 cm (1990) and 19.7 cm (1991) for unoccupied areas. At the end of summer drought, adults occupied habitats that were deeper and larger, and the percent decrease in area and depth was less than areas containing only immature fish or no fish. The medians of percent decrease in maximum depth were 13% (1990) and 21% (1991) for habitats with adults, 48% (1990) and 41% (1991) for habitats with only immature fish, and 42% (1990) and 33% (1991) for unoccupied areas. By the end of summer drought, habitats with only immature fish were not physically different from unoccupied areas. Loss of total surface area was highest in reaches that contained only immature fish or no fish (range = 36% to 94%). Most Sonora chub lost from evaporating surface waters were immature fish. Ephemeral and unoccupied areas had higher percentages of floating cover and coarser substrates than persistent, occupied areas.

Arizon↗