• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.239-246
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• 2009

To establish a database for artificial seed production of stone flounder Kareius bicoloratus, experiments were conducted to study the characteristics of spawning and fecundity of this species. Broodstocks were captured in the area of Gyeokryeolbiyeoldo, Chungnam, Korea in October 2003 and induced to natural spawning. The broodstock consisted of 12 females (34.5~51.0 cm total length and 540~2,200 g body weight) and 23 males (29.0~38.0 cm total length and 310~680 g body weight). Gonad development began in December and proceeded in the direction of the tail; measurements were made with the naked eye. The tank-held broodstock were reared for 3 months before spawning, which continued for 77 days from January 9 to March 27, 2004. Daylength during the spawning was recorded at the yearly shortest of 9.8~12.1 hours and the water temperature was maintained at $8.4{\sim}12.2^{\circ}C$. The total fecundity was 19,844,000 individuals, among which 15,433,000 individuals (77.8%) were produced during the mid-spawning period. The average bloating rate, egg-fertilization rate and hatching rate of the total number spawned reached 50.4%, 58.5% and 55.6%, respectively, and 93.8% of the hatched fry appeared normal. The number of total eggs in absolute fecundity per total length was proportional to both lengths, as was the number of total eggs in relative fecundity per total length. The number of total eggs in absolute fecundity per body weight was proportional to body weight as was the number in relative fecundity per body weight except that the number in relative fecundity per gram decreased after a peak in increased body weight at a certain point.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.628-636
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• 2020

Morphological (cyst shape, color, and sizes [length (L), maximum width (W), volume and "a" (L/W)]), structural (vulvar cone slope angle [VCSA], surface wrinkle [VCSW], cyst wall thickness, composition, and texture) and biological characteristics (fecundity, hatching, and emergence [number of second-stage juveniles (J2) from a cyst]) in preceding Heterodera glycines (Hg), currently-recorded H. sojae (Hs) and H. trifolii (Ht) were examined by microscopy. Cysts were lemon-shaped, indicating the genus is Heterodera except for Hs that formed frequently globular cysts with significantly flatter VCSA (102.2°) with smooth VCSW than Hg (50.6°) and Ht (82.0°), but not genus Globodera because of the presence of vulvar cone in Hs. Ht was significantly larger in all morphological characteristics than Hg and Hs, suggesting Ht may be diagnosed differentially by cyst sizes and also host plant preferences. Hs showed smaller "a" value with more globular shape and stronger structures with more thickened and strengthened collagen-like texture of cyst wall than Hg and Ht. This suggests Hs may be diagnosed differently by structural characteristics from the others, especially Hg with similar cyst sizes. There were no significant differences in emergence (inoculum potential) among cyst nematodes due to the offset of fecundity and hatching rate; however, the inoculum potential of Hs may be not so persistent as Hg and Ht in fields because of its lower fecundity and higher hatching rate (causing rapid inoculum loss) than the others. These characteristics of cysts provide information useful for simple and differential diagnoses and reliable management of cyst nematodes.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.361-368
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• 2009

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, $12{\pm}1^{\circ}C$, RH $70{\pm}10%$, in dark condition. Overall, an appropriate temperature for cold storage was $10^{\circ}C$ for O. laevigatus and $8^{\circ}C$ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at $10^{\circ}C$. The O. laevigatus stored at $10^{\circ}C$ for $10{\sim}50$ days laid $37.1{\sim}120.5$ eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was $16.5{\sim}53.7%$ of normal fecundity. P. persimilis stored at $8^{\circ}C$ for $7{\sim}2$ days with (food eggs of Tetranychus urticae) laid $11.9{\sim}18.9$ eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was $45.1{\sim}71.6%$ of normal fecundity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.255-263
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• 2014

We investigated the reproductive characteristics of Lycodes tanakae in the coastal waters of the middle East Sea to elucidate the species' population structure. We investigated Lycodes tanakae maturation and spawning based on samples collected by Danish seine and gill nets from January 2012 to December 2013. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. The spawning period was December to February, while fecundity ranged from 1,677 eggs at 57.3 cm (total length;TL) to 6,445 eggs at 75.7 cm. The relationship between TL and fecundity (F) was $F_e=6E-05TL^{3.127}$ ($R^2$ = 0.516), and F increased with increasing TL. We estimated the TL at 50% group maturity as 60.4 cm for females and 59.8 cm for males. This study is the first report of Lycodes tanakae reproductive characteristics in the coastal waters of the middle East Sea.

• Clinical and Experimental Reproductive Medicine
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• v.41 no.2
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• pp.75-79
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• 2014

Objective: To study the effect of body composition on reproduction in women with unexplained infertility treated with a controlled ovarian hyperstimulation and intrauterine insemination programme. Methods: This prospective observational study was conducted on 308 unexplained infertile women who were scheduled for a controlled ovarian hyperstimulation and intrauterine insemination programme and were grouped as pregnant and non-pregnant. Anthropometric measurements were performed using TANITA-420MA before the treatment cycle. Body composition was determined using a bioelectrical impedance analysis system. Results: Body fat mass was significantly lower in pregnant women than in non-pregnant women ($15.61{\pm}3.65$ vs. $18.78{\pm}5.97$, respectively) (p=0.01). In a multiple regression analysis, body fat mass proved to have a stronger association with fecundity than the percentage of body fat, body mass index, or the waist/hip ratio (standardized regression coefficient${\geq}0.277$, t-value ${\geq}2.537$; p<0.05). The cut-off value of fat mass, which was evaluated using the receiver operating characteristics curve, was 16.65 with a sensitivity of 61.8% and a specificity of 70.2%. Below this cut-off value, the odds of the pregnancy occurrence was found to be 2.5 times more likely. Conclusion: Body fat mass can be predictive for pregnancy in patients with unexplained infertility scheduled for a controlled ovarian hyperstimulation and intrauterine insemination programme.

• Journal of Aquaculture
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• v.17 no.1
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• pp.30-38
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• 2004

To estimate the spawning period the annual change of gonadosomatic index (GSI) were examined from January 2000 to December 2001. Fecundity, spawning frequency and egg diameter were measured by ocular observation. Germ cell differentiation during gametogenesis, the reproductive cycle and the first sexual maturity of greenling Hexagrammos otakii were observed under light microscopy from January to December, 2000. GSI began to increase in August and reached the maximum in November when ovary was getting mature. The reproductive cycle of H. otakii can be divided into five successive stages in females: early growing stage (July), late growing stage (July to August), mature stage (September to October), ripe and spent stage (September to December), and recovery and resting stage (December to June). Males showed four successive stages : growing (June to August), mature (August to October), ripe and spent (September to December), and recovery and resting stage (December to May). According to the frequency distributions of egg diameter in spawning season, H. otakii could be one of polycyclic species spawning 2 times or more during one spawning season. Number of total eggs and mature eggs in the absolute fecundity were related to the standard length and body weight, respectively. Number of total eggs and mature eggs in relative fecundity were also proportional to the standard length, but rather these numbers decreased with body weight. Percentages of first sexual maturity of females and males in greenling were over 50% from 19.1 to 21.1cm in length, and 100% for fish over 25.1cm in length. Therefore, both sexes are ready to reproduce after one year old.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.115-122
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• 2012

Frequency distribution of carapace width, relative growth, sex ratio and fecundity of blue crab Portunus trituberculatus in Younggwang adjacent water were investigated. A total number of individuals collected for this study were 658(Males : 305 and females : 353). Water temperature and salinity of the study areas varied from 5.9 to $27.3^{\circ}C$ and 28.1 to 31.6 psu, respectively. The carapace length-width and carapace width-weight relationship was calculated and the equations obtained are; For males; CL = 1.3652CW + 22.495($R^2$=0.741), $TW=0.0068CW^{2.4001}$($R^2$=0.749), For females; CL = 1.3073 CW + 25.684($R^2$=0.791), $TW=0.0061CW^{2.4231}$($R^2$=0.801). The sex ratios(Males : females) for blue crab were 0.86 : 1. The value of correlations coefficient between total weight and fecundity of the blue crabs was higher that of between carapace width and fecundity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.410-418
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• 2006

Sexual maturity and growth characteristics of Octopus minor were investigated in 796 individuals from mud flats in Goorori, Muan-Goon, Korea. Gonadosomatic index (GSI) peaked between June and July in females and between November and January in males. The discrepancy in the index peaks between females and males might result from the earlier sexual maturation of males. The sex ratio was biased toward females (68%) in April and toward males (78%) in September, although the differences were not significant (p>0.05). In females, about 50% of individuals with a mantle length of 70.6 mm were sexually mature versus 100% of individuals with mantle lengths over 80 mm. In females, fecundity was also related to size, ranging from 44 eggs in individuals with a mantle length of 54 mm to 179 eggs in the female with a mantle length of 100.5 mm. The relationship between mantle length (ML) an body weight (BW) was BW=0.008 ML$^{2.2797}$ (n=389, r$^2$=0.83, p<0.01) in males and BW=0.029 ML$^{2.2797}$ (n=407, r$^2$=0.74, p<0.01) in females. Analysis of co-variation showed that the difference in the slopes of the two regression lines was significant (p<0.01). Analysis of mantle length-frequency for each month revealed 1 to 3 normal distribution modes. The growth parameters obtained by fitting the modal progression to the seasonalized von Bertalanffy growth function (VBGF) were ML$\infty$= 112.38 mm, K=1.9, C=0.90, and WP=0.1. The results indicate that the seasonal growth oscillation of the stock is very strong and winter is the season when growth is the slowest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.927-937
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• 2022

The reproductive characteristics of Pacific anchovy, Engraulis japonicus were investigated using samples randomly collected from the southern waters of Korea between January and December 2021. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), egg diameter, fecundity, and fork length (FL) at sexual groups maturity of 50%, 75% and 97.5%, and sex ratio (female:male). GSI value showed two peaks in May and August; however, microscopic analysis of E. japonicus gonad tissue revealed that the spawning period was from March to October. The main spawning seasons for the entire populations were from April to June and August to September. The overall sex ratio was female-biased (1 females, 0.89 male). The fecundity (F) of female anchovies ranged from 429 eggs at an FL of 8.0 cm to 13,824 eggs at an FL of 14.9 cm and the relationship between FL and F was 0.0788FL^4.422. The FL at 50% group maturity was 8.26 cm for female anchovies. Based on the results, we suggest that the reproductive cycle in Pacific anchovies may be related to pulses in water temperature and the sexual cycle of the fish.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.421-428
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• 2008

With the comparison of native Orius strigicollis (Poppius) to European O. laevigatus (Fieber), we investigated biological characteristics such as developmental period, fecundity, life span, predation ability, and augmentation after release. Experiments were carried out at five temperature condition, $15^{\circ}C\;20^{\circ}C,\;25^{\circ}C\;30^{\circ}C$, and $35^{\circ}C$. In the case of O. strigicollis, egg period was $3.1{\sim}14.9$ days (hatchability: $46.7{\sim}88.2%$), and developmental period of nymphs was $9.4{\sim}42.8$ days (survival rate: $2.4{\sim}96.5%$). Fecundity at each temperature was 28.1, 107.9, 123.6, 127.3, and 18.1, respectively. Life span of adults was 63.4, 40.1, 22.1, 18.3, and 11.0 days, respectively. In the case of O. laevigatus, egg period was $3.1{\sim}13.5$ days (hatchability: $65.0{\sim}89.9%$), and developmental period of nymphs was $9.3{\sim}42.0$ (survival rate: $4.3{\sim}80.6%$) days. Fecundity at each temperature was 101.8, 218.6, 224.5, 219.5, and 15.7. Life span of adults was 70.6, 66.4, 32.6, 34.5, and 7.3 days, respectively. In long-day condition (16L:8D), fecundity of O. strigicollis and O. laevigatus was 105.8 $(18^{\circ}C){\sim}142.4(25^{\circ}C)$ and 109.5 $(18^{\circ}C){\sim}191.5(25^{\circ}C)$, respectively. In short-day condition (10L:14D), fecundity of them was 1.0 $(18^{\circ}C){\sim}31.8(25^{\circ}C)$ and 63.0 $(18^{\circ}C){\sim}198.8(25^{\circ}C)$, respectively. Daily prey consumption of second instar Frankliniella occidentalis was 14.3 and 10.9, respectively. In greenhouse, density of O. strigicollis begins to increase from mid May and peaked about early July (1.8 individual/flower), while that of O. laevigatus begins to increase from mid March and peaked about early June (6.6 individual/flower).