• Parasites, Hosts and Diseases
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• 제37권2호
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• pp.101-107
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• 1999

Rats were immunized through an initial infection with 1,000 filariform larvae (L3) of Nippostrongylus brasiliensis and after complete expulsion of worms they were challenged with 1,000 L3 of Strongyloides venezuelensis to investigate whether cross-resistance developed against a heterologous parasite. Nippostrongylus brasiliensis immunized rats developed a partial cross-resistance against S.venezuelensis migrating larvae (MSL3) in the lungs and adult worms in the small intestine. The population of MSL3 in the lungs were significantly lower (p<0.05) in immunized rats($22.0{\;}{\pm}{\;}7.4$) compared with controls ($105.0{\;}{\pm}{\;}27.6$). The populations of adult worms, egg output and fecundity were initially decreased but from day 14 post-challenge they did not show any significant difference between immunized and control rats. However, the length of worm in immunized rat was revealed as retardation. Peripheral blood eosinophilia was significantly decreased (P<0.05) on day 7 post-challenge and then gradually increased which peaked on da 42 post-challenge when most of the worms were expelled. these results suggest that peripheral blood eosinophilia is strongly involved in the worm establishment and expulsion mechanisms.

• 수산해양기술연구
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• 제48권2호
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• pp.118-127
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• 2012

The reproductive ecology of the glowbelly, $Acropoma$ $japonicum$ was examined using 637 specimens collected monthly from January to December 2006 in the coastal waters off Gori, Korea. The specimens ranged in standard length (cm, SL) from 2.9 to 11.4cm for female, 2.7 to 10.5cm for male. The gonadosomatic index (GSI) of female was highest in September and decreased until December, and the spawning season lasted from August to November. The monthly sex was not different significantly ($x^2$-test, p>0.05). The size at 50% maturity was estimated at 6.0cm SL. $A.$ $japonicum$ was multiple spawner that spawn on more than one occasion in a single spawning season, and the maximum egg diameter was 0.75mm. Fecundity (F) ranged from 12,052 to 104,246 eggs, with the mean of 38,321 eggs. The relationships between fecundity and standard length (cm, SL), body weight (g, BW) were estimated as $F=86.278SL^{2.9652}$ ($R^2$=0.7970) and $F=3036BW^{1.0081}$ ($R^2$=0.7992), respectively.

• 수산해양기술연구
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• 제50권2호
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• pp.154-161
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• 2014

Maturity and spawning of the giant Pacific octopus, Octopus dofleini was investigated based on the samples collected in the coast of Gangwondo, East Sea, from January to December in 2009. Individuals of mature stage had a higher occurrence rate from February to May, and gonadosomatic index (GSI) also showed a higher value from February to May than the other months. For that reason, the spawning period was estimated from February to May with the main spawning period from March to May. The total number of eggs in the fecundity (F) ranged from 9,045 in 11.0 kg (TW) to 148,682 in 16.5 kg (TW), which was proportional to total weight (TW), and the relationship between total weight and fecundity was $F=0.185{\times}TW^{2.238}$ ($R^2=0.389$). The total weight at 50% group maturity (TW0.5) of female was estimated to be 12.2 kg.

• Fisheries and Aquatic Sciences
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• 제21권3호
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• pp.12.1-12.15
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• 2018

A preliminary investigation of length-weight relationship, condition factor and reproductive ecology of African pike fish, Hepsetus odoe, was conducted between June to August 2010 in Lake Eleiyele. A total of 90 samples of the fish species were caught by fishermen using gill nets. The results obtained showed that fish species had isometric growth pattern (contrary to negative allometry expected) with the growth exponent, b value of 2.64, that is not statistically different from 3 and with high statistical power of 0.866 when tested. The mean condition factor, K, was found to be 2.6, indicating that the fish species were in good condition in the study area. For reproductive biology, mean fecundity and gonadosomatic index were found to be 1349 eggs and 3.53% respectively. This study was necessary to fill the knowledge gap and provide information for management and conservation of the investigated species in the lake system. This study recommended that further research needs to be conducted because the sampling was carried out in the rainy season period and within a quarter of a year.

• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.271-277
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• 2007

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are fully flurorinated organic compounds which are highly persistent in environment and accumulated in organism. These chemicals are released to the environment at their manufacture, during their use in industrial and consumer applications and from disposal after their use. The purpose of this study was to determine the effects of PFOA and PFOS on the freshwater flea (Moina macrocopa). Acute toxicity test and chronic toxicity test were performed for 2 days and 10 days, respectively. Acute toxicity was assessed on the basis of mortality, while chronic toxicity was assessed by fecundity as well as mortality. The acute toxicity studies on PFOA and PFOS showed that the values of $LC_{50}$ were $73.9\;mg/L\;and\;27.7\;mg/L$ respectively. In the chronic toxicity test, fecundity was reduced significantly at 24.1 mg/L of PFOA and 9.3 mg/L of PFOS, respectively. Conclusively, the results of this work suggest that Moina macrocopa could be a suitable model organism for screening and assessing of environmental pollutants in water.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.279-284
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• 2021

The dung beetle, Gymnopleurus mopsus (Coleoptera: Scarabaeidae), is one of endangered species in South Korea. It was last recorded in 1971. To restore this species, we introduced G. mopsus populations from eastern and southern regions of Mongolia in July 2019 and August 2019, respectively. One of the main tasks for the restoration of endangered insects is to develop breeding techniques to eventually incorporate these insects into the restoration system. In a series of laboratory experiments, we investigated effects of short-term hibernation periods on life-history traits of G. mopsus. Adult G. mopsus that had hibernated for 30, 60, and 90 days had lower survival rates than adults that had hibernated for 120 days. We also compared developmental time of these four experimental groups and found a significant difference in the egg - phase. However, the duration of hibernation did not affect the fecundity, brood-ball size, or body size of F1 adults. Follow-up studies are currently being conducted to further investigate the effect of a short-term hibernation period on population growth of G. mopsus under laboratory conditions.

• 한국수산과학회지
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• 제55권5호
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• pp.575-582
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• 2022

This study revealed the reproductive biology of pointhead flounder Cleisthenes pinetorum, in the middle of the West Sea of Korea. We collected samples using gill net and drag net fisheries in coastal waters from January to December 2019. Mmonthly gonodosomatic index and maturity stage results showed that the spawning period was October to December, and the females grew faster than the males. The fecundity ranged from 16,728 to 1,039,616 number of eggs, and the relationship between TL and fecundity (F) was 0.0000003TL^4.7434 (R²=0.4898). The size-frequency distribution of eggs suggested that C. pinetorum spawm once during a spawning period. The length at 50% maturity for females was estimated to be 18.9 cm.

• 농업과학연구
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• 제50권3호
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• pp.507-512
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• 2023

The traditional oviposition ground for indoor breeding of Luciola lateralis is moss. This study was conducted to find the most suitable alternative oviposition ground that can maintain or increase the oviposition rate of L. lateralis while addressing the problems of larva collection time and larva loss that occur when moss is used. As alternative candidate oviposition ground comprising six colors of non-woven fabric and felt were used to measure the fecundity variation rate of L. lateralis with respect to the color and material of the oviposition ground. In addition, measure the fecundity variation rate of L. lateralis in moss, a traditional oviposition ground, was also measured and investigated for comparison. The investigation showed that the average number of eggs in the non-woven fabric group was higher than that in the felt group. The yellow non-woven fabric had an average number of eggs that was more than 100 times higher than of moss used as a traditional oviposition ground. In the space where the six color non-woven fabric were together, L. lateralis concentrated its oviposition on yellow. These results showed that yellow non-woven fabric can be sufficiently used for efficient indoor mass breeding of L. lateralis while addressing problems caused by moss, a traditional oviposition ground.

• 한국응용곤충학회지
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• 제55권2호
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• pp.149-160
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• 2016

기장테두리진딧물의 온도의존적 발육과 산자(산란) 특성을 구명하기 위하여 6개의 항온조건(10, 15, 20, 25, 30, $35{\pm}1.0^{\circ}C$, RH 50~70%, 16L:8D)에서 실험을 실시하였다. 약충의 발육기간은 $10^{\circ}C$에서 42.9일과 $30^{\circ}C$에서 4.7일로 온도가 증가할수록 발육기간이 감소하였다. 약충은 $35^{\circ}C$에서 2영기 이후 성충까지 발육하지 못하였다. 선형모형 결과 약충의 발육영점온도는 $8.3^{\circ}C$, 발육 유효적산온도는 101.6DD 이었다. 약충 발육율과 온도와의 관계는 비선형 Lactin 2으로 잘 설명되었다. 약충 발육기간의 분포는 Weibull 함수를 이용하여 분석하였다. 성충수명은 온도가 증가함에 따라 감소하였는데, $15^{\circ}C$에서 24.0일, $30^{\circ}C$에서 4.3일의 범위에 있었고, $10^{\circ}C$에서 비정상적으로 수명이 짧았다 (11.1일). 총산자수는 $20^{\circ}C$에서 38.2마리로 최대값을 보였고, $10^{\circ}C$에서 3.4마리로 최소값을 나타냈다. 본 실험의 결과를 통하여 무시 성충의 산자모형을 작성할 수 있는 온도별 총산자수 모형, 연령별 누적생존율 모형, 연령별 누적 산자율 모형 및 생리적 연령 계산을 위한 성충 노화율 모형을 제시하였다.

• 한국응용곤충학회지
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• 제55권2호
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• pp.119-128
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• 2016

본 연구는 양배추에서 무테두리진딧물의 온도발육실험, 성충수명, 산자실험을 통해 매개변수를 추정하여, 약충의 온도발육모형, 무시성충의 산자모형 작성에 필요한 기본모형들을 제공하기 위해 실시하였다. 6개의 온도(10, 15, 20, 25, 30, $35{\pm}1^{\circ}C$, 16L:8D)에서 실험한 결과로 저온인 $10^{\circ}C$에서는 성공적으로 발육하지 못했다. 약충 발육기간은 온도가 증가할수록 $30^{\circ}C$까지는 감소하였고 $35^{\circ}C$에서는 다시 증가하였는데, $15^{\circ}C$에서 18.5일, $30^{\circ}C$에서 5.9일 이었다. 약충전체 직선회귀식에서 발육영점온도(DT)는 $7.9^{\circ}C$로 나타났으며, 유효적산온도(DD)는 126.3일이었다. 전기약충(1+2령), 후기약충(3+4령), 전체약충 발육률에 대한 비선형모형(Lactin 2 model)과 발육기간 분포 모형(Weibull model)을 작성하였다. 성충수명은 $15^{\circ}C$에서 비정상적으로 18.2일을 보였고, $20^{\circ}C$에서 24.4일, $30.0^{\circ}C$에서 16.4일의 범위에 있었으며, 성충 생리적 연령계산을 위한 노화율 모형작성에 이용되었다. 총 산자수는 $20^{\circ}C$에서 91.6마리로 최대값을 보였다. 본 연구를 통하여 무테두리진딧물 무시성충 산란모형 작성에 필요한 온도별 총산자수, 연령별 누적산자율, 연령별 생존율 모형 등 3개의 기본모형을 추정하였다.