Publications

The U.S. Fish and Wildlife Service has an ongoing program to assess the feasibility of reestablishing naturally spawning populations of Lahontan cutthroat trout in the Truckee River-Pyramid Lake system in Nevada. Previous in situ egg-survival studies have documented a 100 percent mortality of cutthroat trout eggs artificially planted in potential spawning gravels in the Truckee River...

Annulus formation on opercula of the cui-ui Chasmistes cujus in Pyramid Lake, Nevada, was validated over an 8-year interval. Many fish were old, as old as 41 years of age, As many as three annuli were hidden (covered by supporting bone) in older fish. Growth was rapid during the first 10 years, slow from 10 to 20 years, and extremely slow or nil after 20 years. Age and growth were...

Digestive tract evacuation in northern squawfish (Ptychocheilus oregonensis) (170–1900 g) was studied in fish allowed to feed voluntarily on salmon (4–70 g) at three water temperatures (10, 15, and 20 °C). Squawfish were sacrificed at 1- or 2-h intervals until evacuation approximated 90%. Amount of food evacuated for a given time interval increased approximately three times as the...

Principal components of water reuse systems include ammonia removal, disease control, temperature control, aeration, and particulate filtration. Effective ammonia removal techniques include air stripping, ion exchange, and biofiltration. Selection of a particular technique largely depends on site-specific requirements (e.g., space, existing water quality, and fish densities). Disease...

A small-scale water reuse system (150 L/min) was developed to create an environment for observing fish under a variety of temperature regimes. Key concerns of disease control, water quality, temperature control, and efficiency and case of operation were addressed. Northern squawfish (Ptychocheilus oregonensis) were held at loading densities ranging from 0.11 to 0.97 kg/L per minute and...

Abstract not available

Survival from smolt to adult for full and half-sib families of coho salmon Oncorhynchus kisutch was used to identify families with the highest survival rates at Big Creek Salmon Hatchery in Oregon. Adult fish from families with high survival were bred selectively for four consecutive generations in an attempt to increase smolt survival. A significant improvement in survival in the select...

No abstract available.

For greatest survival, first-feeding halibut Paralichthys californicus and diamond turbot Hypsopsetta guttulata required food by the day of total yolk absorption. Some halibut larvae survived if fed 1 or 2 d after yolk depletion, but their growth rate was significantly less than larvae fed earlier. Survival of 3-wk-old larvae was greater in treatments with shorter starvation periods. A...

No abstract available.

eutralizing monoclonal antibodies were developed against strains of infectious hematopoietic necrosis virus (IHNV) from steelhead trout Salmo gairdneri in the Deschutes River of Oregon, chinook salmon Oncorhynchus tshawytscha in the Sacramento River of California, and rainbow trout Salmo gairdneri reared in the Hagerman Valley of Idaho, USA. These antibodies were tested for...

No abstract available.