Plasma 11-oxotestosterone and gonadotropin during the beginning of spermiation in rainbow trout (Salmo gairdneri R.)

The spermiation period in the rainbow trout ( Salmo gairdneri ) . Plasma gonadotropin and androgen levels , sperm production and biochemical changes in the seminal fluid

Plasma immunoreactive t-GTH and androgens, sperm production and biochemical changes in seminal fluid were studied during the spermiation period in rainbow trout. The volume of sperm collected by hand-stripping was very low (< 0.1 ml) at the onset of spermiation, increased slowly during the next 4 weeks and sharply thereafter. Plasma t-GTH was high (6 ng/mi) at the onset and then decreased ; the...

Lactate and Proton Dynamics in the Rainbow Trout (salmo Gairdneri)

Chronically cannulated rainbow trout were subjected to 6 min of severe burst exercise and monitored over a 12 h recovery period. There were shortlived increases in haematocrit, haemoglobin, plasma protein, Na and Cl~ levels. Plasma [Cl~] later declined below normal as organic anions accumulated. A much larger and more prolonged elevation in plasma [K] probably resulted from intracellular acidos...

Toxicokinetics of Fenvalerate in Rainbow Trout (Salmo Gairdneri)

An in vivo rainbow trout (Salmo gairdneri) preparation was used to evaluate the gill uptake and toxicokinetics of [3H]fenvalerate ([R,S]-α-cyano-3-phenoxybenzyl [R,S]-2-[4-chloro-phenyl]-3-methylbutyrate), a synthetic pyrethroid insecticide. Fish were exposed to technical-grade fenvalerate (0.28 or 23 ng/L) or an emulsifiable-concentrate formulation (16 ng/L) for 36 to 48 h. No significant effe...

Nocardial Infection in Hatchery-reared Fingerling Rainbow Trout (salmo Gairdneri).

Testicular feed back on the hypothalamo - pituitary axis in rainbow trout ( Salmo gairdneri R . )

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...