• Advances in nano research
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• v.9 no.1
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• pp.15-24
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• 2020

Iron has a crucial role in growth as part of metalo-proteins like haemoglobin or myoglobin, enzymes; they are also involved in energetic reactions. Iron plays a vital role in fertility. At high doses, Iron has a harmful consequence on the reproductive system, which can be strongly reflected the final stage of spermatogenesis. Nutritional products are claiming to use nanotechnology and it is important to recognize the potential toxicity of nano-sized nutrients. Recently iron nanoparticles were proposed as a food additive for poultry. The objective of this study was to investigate the effects of L-cystein coated iron oxide nanoparticles on reproductive performance in male quails. The results of Fourier Transform Infrared Spectrometer, Alternating Gradient Force Magnetometer and Scaning Electron Microscopy showed that iron oxide nanoparticles was produced and have been coated with L-cycstein (Fe₃O₄-Cys NPs). A total of 100 one-week-old quail chicks were randomly placed to five groups of five replicates. Four quails (two male and two females) were raised in an individual cage for each replicate. The five experimental treatment diets consisted; negative control diet, with no Iron supplementation; positive control diet supplemented with 60 mg/kg of Fe₃O₄; treatment diets supplemented with 0.6, 6 and 60 mg/kg of L-cystein coated iron oxide nanoparticles. The hemoglobin, Red blood cell, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, gonadal somatic index, daily sperm production, total testicular sperm and sperm viability of the male quails that were fed with diet supplemented by 0.6 mg/kg of Fe₃O₄-Cys NPs were improved as compare with negative control. This study showed that not only the use of the Fe₃O₄-Cys nanoparticles had no side effects but also it can be used as a feed additive to improve the reproductive performance in male quails.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.37-43
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• 2012

We have investigated the effect of melatonin (MLT) on specific growth rate (SGR% $day^{-1}$), condition factor (k), gonado-somatic-index (GSI), histological structures of gonads, serum as well as gonadal protein and lipid in Nile tilapia Oreochromis niloticus. MLT treatment in the dose of 25 ${\mu}g/L$ for three weeks reduced SGR% $day^{-1}$ ($0.9{\pm}0.04$) as compared to control ($1.23{\pm}0.026$). The GSI value was significantly (p<0.05) reduced to $1.77{\pm}0.253$ from control where it was $2.56{\pm}0.25$. Serum protein level increased from $9.33{\pm}2.90$ mg/ml (control) to $11.67{\pm}1.45$ mg/ml after MLT treatment while there was depressed serum triglycerides ($86.16{\pm}1.078$ mg/dl) and cholesterol ($126.66{\pm}0.88$ mg/dl) as compared to control values where these were $123.0{\pm}1.23$ mg/dl and $132.0{\pm}1.65$ mg/dl respectively. Histological structure of ovary showed small eggs of early perinucleolus stage after MLT treatment while testicular structure of control and MLT treated fish was more or less similar. It is concluded that exogenous melatonin suppressed SGR% $day^{-1}$, GSI, ovarian cellular activity, protein and lipid biosynthesis, in tilapia suggesting that melatonin is useful in manipulating the gonadal maturity in fishes.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.115-121
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• 2014

Eyestalk ablation (ESA) is commonly used in aquaculture to stimulate ovarian maturation in crustaceans, and methyl farnesoate (MF) affects crustacean molting and reproduction. To investigate the physiological effects of ESA and MF treatments on the shrimp Litopenaeus vannamei, we compared the effects of single eyestalk removal and MF injections. The ESA group had the lowest survival rate (50%), and individuals in the $0.1{\mu}g$ and $1.0{\mu}g$ MF-treated groups had survival rates of 80 and 73.3%, respectively. Conversely, molting numbers were highest in the ESA group, and similar to those of the 1.0-${\mu}g$ MF group. To investigate shrimp growth, we measured body weight during the experimental period and found that individuals in the ESA and $1.0{\mu}g$ MF groups showed significant increases in body weight. Furthermore, to investigate the effects of ESA and MF treatments on gonadal maturation, the gonad somatic index (GSI) was calculated after the experiment. All treated groups (ESA and MF) had higher GSI values than the control group, but the ESA and $1.0{\mu}g$ MF groups were not significantly different. Using histological ovary analysis, we determined that all treated groups showed indications of the previtellogenic stage, unlike the control group (immature stage). These results suggest that the high-MF-concentration treatment produced effects similar to those of ESA with respect to molting number, growth, and ovarian maturation.

• Journal of Aquaculture
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• v.11 no.2
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• pp.173-182
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• 1998

The study has been conducted to understand gonadal development and the effects of $17^{\alpha}$-methyltestosterone on sex inversion of the red spotted grouper, Epinephelus akaara. Fish were collected from Deukyand bay in the southern coast of Korea in August, 1996 and then they had been cultivated at the indoor tank until August, 1997. Gonad somatic index (GSI) in the females of both treated and control group began to increase from February when water temperature was rainse again, and reached the maximum value in August, whereas it had decreased from September adn thereafter maintained relatively low value until January. Unlike females, GSI in the male or intersex of treated groups decreased after June. Hepatosomatic index (HSI) of the control group tended to show the relatively low around Autumn, whereas it showed relatively highr value in April and June when the ovary was in the growing stage. Although the treated groups showed relatively higher value of the HSI than the control, hte paterns in monthly variation of HSI were similar to the control. Sexual change of the female grouper to the male was attempted by acceleration with oral administration of $17^{\alpha}$-methyltestosterone at the dose of 0.2 and 0.5mg/kg fish for 120days. Transitional hermaphroditic gonads were observed from the various size of groupers ranging 21.0 to 36.1 cm in total length, while the functional males could be induced from th individuals of 28.8 to 33.5cm in total length. This result indicated that larger groupers than 30cm in total length should be used for sex inversion to maleness with $17^{\alpha}$-methyltestosterone.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.117-125
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• 1999

We investigated the reproductive cycles of two freshwater fishes, Moroco oxycephalus and M. lagowskii, in Korea. Seasonal changes in gonadosomatic index (GSI) and gonads were investigated histologically from April 1998 to April 1999. The reproductive cycles of two species were not shown any differences. The reproductive cycle can be divided into 5 phases : phase I (spent phase), phase II (immature phase), phase III (early developing phase), phase IV (late developing phase), and phase V (ripe phase). In phase I, the gonads of two species began to lose distinctly their weights from mid April, and reached the lowest GSI in late July (phase II). In September, the GSI values of testis and ovary increased very slowly (phase III) and gonadal developments rested during the winter season (phase IV). In March, the GSI values of M. oxycephalus and M. lagowskii began to increase, and reached the maximum in April (phase V). From the cyclic changes in the GSI and histological analyses, the spawning period was between mid April and mid May.

• Journal of Aquaculture
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• v.13 no.2
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• pp.129-135
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• 2000

Genetic variabilities of local populations of Anthocidaris crassispina and Hemicentrotus pulcherrimus were analysed by random amplified polymorphic DNA (RAPD) technique with phenotypic variabilities in timing of gonadal maturation, reproductive output and size of individuals in Cheju. H, pulcherrimus, collected from 4 locations during March 1997, indicated that Daepo individuals were significantly smaller than that at Hamdok, Wimi site A and Wimi site B (ANOVA, p>0.001). Gonodal-somatic index (GSI) of the Wimi site B population was significantly higher than that of three other locations (ANOVA, P>0.0001). An ANOVA test conducted on test size of A. crassispina, harvested from six different locations of Cheju during June 1997, indicated that the size of individuals from Pophwan was significantly smaller (P>0.0001) than that from five other locations. GSIs of urchin m Wimi and Hanlim were significantly higher than that from Pohwan and Oedo (ANOVA, p>0.0001). Genetic similarity, calculated from k13 primer analysis of total DNA, among the six different populations of A. crassispina varied from 0.67 to 0.92, and the values for H. pulcherrimus from 0.60 to 0.73; thus there was no genetic variation among different populations of the same species. Therefore, the populations are genetically homologous and the observed phenotypic variabilities were possibly associated with water temperature and food.