Active sodium uptake from dilute media has been described extensively in a number of aquatic vertebrates, and we have some understanding of the cellular mechanisms involved (Koefoed-Johnsen & Ussing, 1958; Ussing & Windhager, 1964; Biber, Chez & Curran, 1966). While chloride transport has been neglected by comparison, chloride uptake systems are found in diverse groups of animals and deserve mo...

The synergistic activities of cyclopropenoid fatty acids (CPFA), epoxyoleic acid, sesame seed oil, and autoxidized salmon oil with aflatoxin Bt were studied in rainbow trout. Sterculia foetida oil (49% sterculic, 7% malvalic acids) and Hibiscus syriacus oil (2% sterculic and 19% malvalic acids) were used as sources of CPFA. The combination of both 112 and 56 ppm CPFA procured from S, foetida oi...

The indirect fluorescent antibody technique has been used successfully for the rapid serological identification of the Streptococcus sp. responsible for streptococcosis of rainbow trout. This technique has been used to identify the Streptococcus sp. in pure cultures and smears made from experimentally infected and diseased fish.

A testicular feed back on the hypothalamo-pituitary system was studied in male rainbow trout (Salmo gairdneri) after bilateral castration and steroid or testicular supplementation. Experiments were carried out at various periods of the spermatogenetic cycle ; in March-April (resting stage), June (initiation of spermatogenesis), October (end of spermatogenesis and before spermiation), and Decemb...

1. Swimming performance and oxygen consumption of normoxic (control) and hypoxia-acclimated (P02 — 40mmHg) rainbow trout, Salmo gairdneri Richardson, were monitored at >145, 60 and 40mmHg. 2. Maximum swimming velocity at 40mmHg was reduced from >54-8cms"' to 41-4cms" in controls and to 40-6cms" in hypoxiaacclimated fish. 3. Normoxic oxygen consumption of control fish ranged from Q-T-SmgOzkg-'h(...

The Fick principle has often been used to estimate the volume flow of water per unit time over the gills of fishes. Application of the Fick principle requires accurate measurement of mean oxygen tensions in water entering and leaving the gills and of total oxygen uptake. Cannulae of various types have frequently been used to sample water entering and leaving the gills (van Dam, 1938; Holeton & ...

Net forces and velocities resulting from in situ contractions of the myotomal musculature on one side of the body were measured at the hypural bones. Forces, velocities and power were determined with the body bent into a range of postures typical of those observed during fast-start swimming. For trout averaging 0.178 m in length and 0.0605 kg in body mass, the muscle system exerts a maximum nor...