• The Korean Journal of Zoology
• /
• v.30 no.1
• /
• pp.10-28
• /
• 1987

Changes of protein synthesis in the isolated egg chambers were studied during oogenesis of Drosophila melanogaster. Protein synthesis did not change much in quantity except that the activity was slightly enhanced at the stages 11 and 12, when new structures such as vitelline membranes and yolk granules were made, but considerably changed in quality during oogenesis. Protein synthesis was believed to occur mainly in the follicle cells, and a number of stage-specific proteins were found to differ at various stages. The observations suggest that proteins synthesized in the cells within chambers as well as those from the outside of the chambers might be directly required for the growth and maturation of oocytes in Drosophila.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.5
• /
• pp.526-535
• /
• 2001

The gametogenesis, reproductive cycle, frequency distribution of egg diameter and fecundity of spotted sea bass Lateolabrax maculatus were investigated by histological observation. The samples were collected at Goheung, Jeonam from December 1996 to November 1997. Gonadosomatic index (CSI) was appeared less than 1.0 in female and male from December to July and began to increase from August and reached the maximum values of female 7.50 and male 2.98 in October. Hepatosomatic index (HSI) was appeared annual maximum value of female 1.97 and male 1.64 in March and then decreased from April. The annual reproductive cycle of this species can be divided into four successive stages: growing stage (July to August), maturation stage (September to October), ripe and spawning stage (October to November) and degeneration and resting stage (November to July). According to the frequency distribution of egg diameter, the development mode of egg was not seperated, formed one mode for the maturation and spawning season, The individual absolute fecundity ranges from $1,726,242\~17,822,576$ eggs, and individual relative fecundity ranges from $29,458\~214,730$ eggs in total length (cm) and $938\~3,363$ eggs in body weight (g). Female and male of L. maculatus were matured when total length were over 50.1 and 45.1 cm, respectively.

• Korean Journal of Animal Reproduction
• /
• v.13 no.2
• /
• pp.70-78
• /
• 1989

Mouse eggs recovered from oviducts at one hourly intervals between 10 and 20 hours after administration of hCG were fixed, stained and then investigated the rate of in vitro fertilization and nuclear maturation. In case of out- bred ICR mice, ovulations were occured between 11 and 13 hours after hCG injection. The stages of in vitro maturation of eggs recovered from female mice at various times after hCG injection were metaphase I, anaphase I, telophase I and metaphase II. However the majority was metaphase I(17.6 to 44.4%) and metaphase II(42.9 to 80.0%) stage. When the eggs were inseminated with epididymal spermatozoa, the fertilization rate was declined as the egg recovery time after hCG administration was delayed. That is, the proportion of eggs undergoing fertilization became higher(68.1 to 77.4%) in the eggs at 12 to 15hr after injection of hCG than those(17.5 to 56.4) at 16 to 20 hr after injection of hCG. Also, when nuclear maturation of the unfertilized eggs were observed at 8 hours after insemination, the majority was in metaphase I and metaphase II and no anaphase I and telophase I were observed.

• Journal of Life Science
• /
• v.9 no.5
• /
• pp.518-524
• /
• 1999

Timing of oviposition, nuclear maturation of oocytes, egg-sperm contact and brooding were observed in the giant fresh-water prawn Macrobrachium rosenbergii reared in the laboratory. When a pre-spawning molted female was transferred to the male, the female oviposited commonly at 5 to 10 hr after mating. The first polar body were extruded within 2-3 min after spawning. The egg chromosome progressed to release second polar body by 30 min and mitotic nuclear division occurred in 8 hr after spawning. Thumbtack-shaped spermatozoa were seen peneterating egg membrane with their spike directed forward. Transformation of spermatozoa and fertilization membrane could not be observed by light microscopy. The elapsed hours from oviposition to the end of brooding wee taken in 5-7 hr. Brood size for female 9 cm and 18 cm in body length was estimated to be 10,000~15,000 and 100,000 eggs, respectively and is proportional to the total length of the berried females. The ovigerous females reared at chlorinity of 2.21~4.25$\textperthousand$Cl. showed a normal egg development up to hatching.

• The Korean Journal of Zoology
• /
• v.26 no.2
• /
• pp.83-93
• /
• 1983

Vitellogenin was purified from the haemolymph of female pupae during egg formation of Bombyx mori using DEAE-cellulose column and its quantitative change in various organs with age ws examined by electrophoresis and immunodiffusion. Vitellogenin is distributed in the haemolymph, fat body, and over the egg maturation and especially maintainsa constant level in the haemolymph until just before emergence, indicating that vitellogenin in released into the haemolymph at the same amount as it is taken up by oocytes during pupal period. Immunologically vitellogenin was confirmed to be in the fat body until 7 days after pupation and to undergo a drastic decline thereafter. Also, the interaction of anti-ovary proteins with haemolymph proteins showed at least 3 homogeneous proteins, indicating that other proteins as well as vitellogenin are involved in egg formation.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.672-681
• /
• 2019

The ecological characteristics of Sargassum macrocarpum, an ecologically and commercially valuable brown alga, were investigated from May 2018 to June 2019 in Jeju Island, Korea. The S. macrocarpum population formed patches at depths of 3-5 m. Growth in the length of the alga reached a maximum of 135.3±20.0 cm in June. The weight of the alga reached a maximum of 3.6±2.1 kg·wet-wt in May. The mean density and biomass of S. macrocarpum was 4.5 individuals·m^-2 and 4.6 kg·wet-wt.·m^-2 in their habitat. Receptacles were observed from April to August and egg release was detected from June to July when the seawater temperatures were 19.3-22.9℃. The developmental initiation of thalli occurred at temperatures above 14.1℃ and maturation required approximately 726.3 degree-days. The reproductive allocation of this alga, calculated from the reproductive frond length(RFL) and reproductive frond weight(RFW) indices to the whole length and weight, reached a maximum of 69.3% in June. The growth and maturation patterns of S. macrocarpum could be divided into vegetative growth (October-January), maturity preparation (February-April), maturation (May-June), egg release (June-July), and resting period (August-September). This was the first study to examine an S. macrocarpum population throughout the entire year in a natural habitat in Jeju Island, Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.45 no.4
• /
• pp.287-291
• /
• 2009

This study examined the maturation and main spawning season of Japanese spear lobsters, Linuparus tirgonus(Von Siebold) captured around Jeju island from January to September, 2008. Carapace length(CL), body weight(BW) and gonad weight(GW) were measured. Gonadosomatic index(GSI) and sex ratio were calculated. In female group, CL showed the highest value in June and decreased after August. GW showed a peak in July and decreased rapidly after August. The mean gonadosomatic Index(GSI) reached a maximum value between June and August. Number of egg ranged from 143,360 to 189,504.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.4
• /
• pp.248-253
• /
• 2007

We studied the maturation and spawning of female Spanish mackerel (Scomberomorus niphonius) based on 445 specimens collected monthly from January to December 2004 in the coastal waters off Busan. The fork length (FL) of S. niphonius ranged from 26.1 to 105.4 cm, the gonadosomatic index (GSI) of the females was highest in May 2004, and the spawning season take place from April to July. A significant difference was detected in the sex ratio between females and males ($X^2$ test, p<0.01). The percentage of sexually mature females exceeded 50% in the 50-60 cm (FL) size group and reached 100% in the over 70 cm (FL) size group. Fecundity (F) varied between 201,156 and 836,426 egg per female. The relationship between F and FL of the fish was expressed as $F=5.8756FL^{3.8465}$. The relationship F and body weight (BW) was expressed as F=581.421 n (BW)-4108.5. The first spawning length was 41.8 cm (FL.)

• The Korean Journal of Malacology
• /
• v.26 no.3
• /
• pp.201-209
• /
• 2010

The investigated of survival rate, sex ratio, condition index, gonad development frequency, gonad index, fertilization rate, hatching rate and time required development of D shape larvae of the ark shell, Scapharca subcrenata. Survival rate was lower in heating group compared with control group (P < 0.05). Sex ratio (female:male) observed 1:0.97 in control group, 1:0.62 in heating group. Condition index was significantly higher in heating group than control group (P < 0.05) and higher increased more than water temperature $17^{\circ}C$ of heating group. Gonad development observed slow in control group but more than ripe stage 80% in heating group (21-28 day, $20^{\circ}C$). Gonad index was higher in heating group compared with control group (P < 0.05). Fertilization rate and hatching rate of the ark shell was observed $82.17{\pm}3.55%$ and $63.57{\pm}2.36%$, respectively. The time required development of D shape larvae of the ark shell was observed 15 hour after fertilization. The suggested that results of the ark shell by heating were effective sex maturation and normal egg development.

• Fisheries and Aquatic Sciences
• /
• v.3 no.3_4
• /
• pp.180-187
• /
• 2000

Reproductive effort and spawning frequency of the two palaemonid prawns, Exopalaemon modestus and Palaemon gravieri, were investigated. In both embryos of the two species, egg size was larger in E. modestus than in P. gravien but for a given size, number of eggs (EN) was fewer in E. modestus. The statistical results revealed that there were significant differences in egg size and EN between the two species. E. modestus living in freshwater environments had larger and fewer offspring than P. gravieri inhabiting marine environments. These findings are consistent with predictions from r- and K-selections models. Reproductive effort (RE) also was higher in E. modestus, suggesting the possibility for E. modestus to invest larger amount of energy per individual offspring. In the two prawns the ovarian dry weight of females with eyed eggs was significantly higher than those with non-eyed eggs. This indicates that the ovarian maturation occurs during the period between the two embryonic stages, suggesting females being potentially of continuous breeding within a single reproductive period. In the both species brood loss did not occur during the incubation period.