@article{mylonas_sullivan_hinshaw_1994, title={THYROID-HORMONES IN BROWN TROUT (SALMO-TRUTTA) REPRODUCTION AND EARLY DEVELOPMENT}, volume={13}, ISSN={["0920-1742"]}, DOI={10.1007/BF00004331}, abstractNote={Gravid brown trout (Salmo trutta) females were injected with various doses of a synthetic gonadotropin-releasing hormone analog (GnRHa), given with or without an injection of triiodothyronine (T3), in order to investigate the potential of T3 (a) to enhance the stimulatory effect of GnRHa on ovulation, and (b) to enhance the growth and survival of the produced progeny. From the time the hormonal treatments were initiated until ovulation was detected 5-38 days later, endogenous plasma T3 levels increased from an average of 3.6 to 11.6 ng ml(-1). Injection with 20 mg T3 kg(-1) body weight, further elevated plasma T3 levels at ovulation (16.0 ng ml(-1). Mean time to ovulation was reduced significantly in fish injected with 10 μg kg(-1) of GnRHa, whereas treatment with lower doses was ineffective. Injection with T3 did not enhance the ovulatory response of brown trout to GnRHa. Unfertilized eggs obtained from T3-injected females had a higher T3 content, suggesting a transfer of T3 from the maternal circulation into the oocytes. Maternal T3 injection had no effect on egg fertilization rates, embryo survival to eyeing and hatching, or the prevalence of abnormal larvae at the time of hatching. Length and weight gain of the progeny during yolk absorption was also not influenced by maternal T3 treatment. At the completion of yolk-sac absorption, progeny from females injected with T3 had a higher prevalence of skeletal abnormalities than controls. The results suggest that in teleosts like brown trout, which have high endogenous circulating T3 levels, treatment of females with T3 does not enhance responsiveness to GnRHa and it has the potential for deleterious effects on their offspring.}, number={6}, journal={FISH PHYSIOLOGY AND BIOCHEMISTRY}, author={MYLONAS, CC and SULLIVAN, CV and HINSHAW, JM}, year={1994}, month={Dec}, pages={485–493} }
 @article{mylonas_hinshaw_sullivan_1992, title={GnRHa-induced ovulation of brown trout (Salmo trutta) and its effects on egg quality}, volume={106}, DOI={10.1016/0044-8486(92)90268-P}, abstractNote={The effectiveness of a GnRH analogue (GnRHa) for inducing ovulation in brown trout was examined, and the effects of the maternal hormone-treatment on egg quality and larval development were evaluated. Two injections of 10 μg/kg body weight of GnRHa given 3 days apart effectively induced ovulation. Within 6 days from the second injection, 80% of the injected fish had ovulated compared to only 10% of the control fish. Mean time to ovulation was reduced significantly (P < 0.01) from 15.4 days in control fish to 5.9 days in fish injected with 10 μg/kg GnRHa. Ovulated eggs from fish injected with this dose of GnRHa had lower fertility, survival to eyeing (eye-pigment formation stage) and hatching rates compared to eggs from fish injected with lower GnRHa doses or from control fish. Survival from hatch to complete yolk-sac absorption was not affected by GnRHa treatment. Reduction of egg quality was correlated with decreased time to ovulation in both control and GnRHa-treated fish, suggesting that poor egg quality did not result directly from the effects of the hormone on the maturing oocytes. Of the egg quality parameters examined, fertility was the one affected most by early ovulation. It is hypothesized that GnRHa-induced maturation caused a reduction in egg quality by disrupting the timing of final oocyte maturation and ovulation.}, number={3-4}, journal={Aquaculture}, author={Mylonas, C. C. and Hinshaw, J. M. and Sullivan, C. V.}, year={1992}, pages={379} }