Induced spawning of milkfish, Chanos chanos, by a single application of LHRH-analogue

Lee, C.-S.; Tamaru, Clyde S.; Kelley, Christopher; Banno, J.E.

doi:10.1016/0044-8486(86)90158-4

Cited by 45 publications

(17 citation statements)

References 13 publications

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“…The GnRHa pellets were produced according to the recipe in Lee et al 11 . The GnRH analog, LHRHa (pGlu‐His‐Trp‐Ser‐Tyr‐D‐Ala‐Leu‐Arg‐Pro‐NHEt; Sigma, St Louis, MO, USA) was dissolved in 50% ethanol and mixed with cholesterol powder.…”

Section: Methodsmentioning

confidence: 99%

Effects of gonadotropin-releasing hormone analog on milt production enhancement in starry flounder Platichthys stellatus

2002

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The treatment of exogenous gonadotropin or gonadotropin‐releasing hormone analog (GnRHa) is able to solve some problems that are caused by small milt volume or viscous milt in artificial insemination of flatfish species. However, the mechanism of the action of the exogenous hormones on milt production has not been well understood. Therefore, experiments were carried out to study the effects of GnRHa on the milt production and characteristics of seminal plasma in starry flounder Platichthys stellatus. Males were implanted with GnRHa pellets at three different dosages (50, 100 or 200 μg/kg body weight) during their natural spawning season. Milt volume and sperm production increased in a dose‐dependent manner after GnRHa pellet treatments. Spermatocrit and sperm concentration were significantly lower in GnRHa treated groups than in the control group. The sperm motility index was high from day 4 to day 49 in all experimental groups including the control group, and it declined after day 49 in all groups except the 200 μg treated group in which it remained high until day 85. During the experimental period, osmolality, K+ and total protein tended to be higher in the control group than in the GnRHa treated groups. The results suggested that GnRHa treatment increased the milt volume and sperm production ability in starry flounder. The increase of milt volume was twice as rapid as the increase of sperm production. No significant differences in physicochemical composition of blood plasma and seminal plasma were found according to GnRHa dosages, but there were significant differences between GnRHa treated groups and the control group.

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Section: Methodsmentioning

confidence: 99%

Effects of gonadotropin-releasing hormone analog on milt production enhancement in starry flounder Platichthys stellatus

2002

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“…GnRHa pellets were produced according to Lee et al (1986). LHRH salmon was dissolved in 50 % ethanol and mixed with cholesterol powder.…”

Section: Experiments 2: Effect Of Gnrha Treatment During the Middle Ofmentioning

confidence: 99%

“…Treatment of fish with slow-release forms of GnRHa, injection with GnRHa microspheres, or implantation with GnRHa-containing pellets typically results in the slow but stable induction of ovulation over a long period (Lee et al 1986;Harmin and Crim 1992;Berlinsky et al 1997;Mylonas and Zohar 2001;King and Pankhurst 2004). Dosesustained GnRHa release stimulates multiple ovulations, but in some species it also stimulates ovarian development in immature fish (Poortenaar and Pankhurst 2000).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, GnRHa has now been successfully tested in a range of marine and freshwater species and has been shown to be effective in improving egg quantity and quality (Lee et al 1986(Lee et al , 1987Poortenaar and Pankhurst 2000;Zohar and Mylonas 2001;King and Pankhurst 2004). GnRHa is a principal stimulator of follicle-stimulating hormone and luteinizing hormone (LH) release in teleost fish.…”

Section: Introductionmentioning

confidence: 99%

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Effect of exogenous hormones on ovulation and gonadal steroid plasma levels in starry flounder, Platichthys stellatus

Lim

2016

Aquacult Int

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The present study was designed to examine the potential for inducing ovulation in starry flounder (Platichthys stellatus) using gonadotropin-releasing hormone analog (GnRHa) and human chorionic gonadotropin (hCG) to assess whether starry flounder are differentially responsive to GnRHa and hCG. Female starry flounder were injected or implanted with different doses of hCG or GnRHa pellets to examine their ovulationinducing potential and effects on plasma levels of testosterone (T), 17b-estradiol (E2), and 17,20b-dihydroxy-4-pregnen-3-one (17,20bP). Blood samples were collected for up to 10 or 25 days post-injection or post-implantation in two separate experiments designed to mimic the early and middle stages of spawning, respectively. Fish treated with the GnRHa pellets (100 lg) showed a significant increase in the total number of stripped eggs relative to the controls. GnRHa administration had no effect on the floating rate or fertilization rate of ovulated eggs in the both experiments, whereas hCG injection affected both of these rates. Plasma T levels were not significantly different between the exogenous hormonetreated and control fish. In contrast, the plasma E2 level was elevated in those fish treated with GnRHa, regardless of injection or implantation, and was accompanied by increased numbers of stripped eggs in both experiments. Treatment with GnRHa resulted in higher 17,20bP levels compared to the controls, and there was a positive relationship between elevated plasma 17,20bP and an increase in ovulated eggs in response to GnRHa treatment. The implantation of starry flounder with GnRHa-containing pellets was effective at inducing sustained ovulation compared to hCG treatment.

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“…The number of LH-RH cells was significantly increased in the forebrain preoptic area of terminal phase males in protogynous bluehead wrasse, Thalassoma bifasciatum The treatment of LH-RH analog further induced sex reversal in bluehead wrasse (Kramer et al, 1993 (Aida, 1983;Hirose etal, 1983), black porgy, A schlegeli (Yueh et al, 1990;Chang and Yueh, 1990a;Chang et al, 1991, Lee et al, 1993, walleye, Stizostedion vitreum (Pankhurst et al, 1986), catfish, Clarias macrocephalus (Ngamvongchon et al, 1986), carp (Ngamvongchon et al, 1987), Atlantic salmon, Salmo salar Crim and Glebe, 1984), seabass, Lates calcarifer (Harvey et al, 1985), rabbitfish, Siganus guttatus (Harvey et al, 1985), and milkfish, Chanos chanos (Lee et al, 1986). Weil and Crim, 1983;Crim and Glebe, 1984 (fig 2).…”

Section: Introductionmentioning

confidence: 99%

A microencapsulated analog of LH-RH accelerates maturation but without stimulating sex reversal in the protandrous black porgy, Acanthopagrus schlegeli

Chang¹,

Yueh²,

Lee³

et al. 1995

Reprod. Nutr. Dev.

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Summary ― The objective of this study was to regulate the reproduction and levels of gonadal steroids in 3-year-old protandrous black porgy (Acanthopagrus schlegeli) by treatment with microencapsulated o-Trp s -luteinizing hormone-releasing hormone (LH-RH analog) during the prespawning season. Twenty-four previously male black porgy were equally divided into 2 groups and injected with vehicle (control group) or with microencapsulated LH-RH analog (LH-RH analog group), respectively. Spermiation and plasma levels of testosterone (T), estradiol-1 7p (E2) and 17a-hydroxyprogesterone (17a-OH P) were measured, after treatment, at intervals of 1-2 weeks for 4 months. Oocyte diameters were also measured after 4, 10, 12, 14 and 16 weeks of treatment. The microencapsulated LH-RH analog accelerated the onset of spermiation by at least 5 weeks. Oocyte diameters were also significantly increased in the LH-RH analog group. The microencapsulated LH-RH analog did not increase the number of sex-reversing females compared with the number in the control group. High levels of plasma E2 were found in the sex-reversing females in the LH-RH analog and control groups during the prespawning and spawning season. Low levels of plasma E2 were observed in the non-reversed males in both the LH-RH analog and the control groups. Similar profiles of plasma T levels were detected in male and in reversing female black porgy in the LH-RH analog and control groups. Plasma 17a-OH P levels were low and constant throughout the experimental period in fish in each group. These findings indicate that the microencapsulated LH-RH analog accelerated gonadal maturation in the black porgy during the prespawning season. Plasma levels of E2 seem to be closely related to the occurrence of natural sex reversal in the protandrous black porgy, A schlegeli.

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Induced spawning of milkfish, Chanos chanos, by a single application of LHRH-analogue

Cited by 45 publications

References 13 publications

Effects of gonadotropin-releasing hormone analog on milt production enhancement in starry flounder Platichthys stellatus

Effects of gonadotropin-releasing hormone analog on milt production enhancement in starry flounder Platichthys stellatus

Effect of exogenous hormones on ovulation and gonadal steroid plasma levels in starry flounder, Platichthys stellatus

A microencapsulated analog of LH-RH accelerates maturation but without stimulating sex reversal in the protandrous black porgy, Acanthopagrus schlegeli

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