• 제목/요약/키워드: eggs number

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잠수관찰을 통한 경남 진해만과 통영 연안 청어 Clupea pallasii의 산란기 추정 (Estimation of Spawning Season of Clupea pallasii in the Jinhae Bay and Coastal Waters of Tongyeong in Gyeongnam Using Scuba Observation)

  • 이용득;이강민;박종율;곽우석
    • 한국어류학회지
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    • 제32권1호
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    • pp.14-20
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    • 2020
  • 이번 연구는 산란기로 알려진 12월부터 2월까지 경남 진해만과 통영 연안에서 잠수조사를 통해 산란회유하는 청어의 산란기를 명확히 밝히는 데 목적이 있다. 경남 진해만에서 2017년 12월부터 2018년 1월까지 3개의 정점에서 총 18회, 통영 영운리 연안에서는 2017년 12월부터 2018년 2월까지 총 24회 잠수조사를 통해 결과를 분석하였다. 조사기간 중 확인된 청어 수정란은 진해만 저도 연안에서 평균 740,274개/㎡, 진해만 구산면 연안에서는 평균 671,718개/㎡였다. 통영 영운리 연안에서는 2017년 12월 30일에 388,444개/㎡개의 수정란이 1회 관찰되었고 그 이후 조사에서는 관찰되지 않았다. 이번 연구결과 경남 진해만과 통영 연안에서 청어 산란은 12월 말에 시작되고 이때의 수온은 평균 7.7℃였다.

Haemaphysalis longicornis 진드기의 사육방법에 관한 연구 (Studies on the Rearing method of the Tick, Haemaphysalis longicornis)

  • 차현성;이주묵;권오덕;채준석
    • 한국임상수의학회지
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    • 제10권1호
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    • pp.101-109
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    • 1993
  • This study was attempted to develop a rearing method of the tick(Haemaphysalis longicornis) at the laboratory in winter. The rearing conditions for ticks in winter were summarized as follows; Even in the winter, under controlled Incubator on 25~3$0^{\circ}C$ and 90~95%, temperature and humidity, respectively, it is possible to rear the ticks normally as on summer. in the usual laboratory room temperature and humidity, 20~$25^{\circ}C$ and 51 ~77%. In the ticks collected in summer, the life span of the ticks, from hatching to death, was 91~129(112.8$\pm$15.2) days in the lagoratory, and the number of the oviposited eggs from a tick were about 1,680~2,460 and the hatching rate of the oviposited eggs was about 95(92~98)%. The life span of the ticks which were reared in the laboratory in winter was 89-138(112.2$\pm$21.1) days, and the number of the oviposited eggs from the tick were about 1,382~2,674 and the hatching rate of them was about 89.5(87~92)%. In the rearing of the tick at the laboratory, the dogs, rabbits and mice were able to use the hosts for the tick. The proper temperature to feed the ticks on the cattle in the cold season was obtained by $Hokalong^{\circledR}$ which were attached on the out side of sac which covered bovine ear where attached ticks.

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광양만 연안에 분포하는 부유성 난 및 자치어의 종조성과 양적변동 (Quantitative fluctuation and species composition of ichthyoplankton in Gwangyang Bay, Korea)

  • 추보라;이성훈;유태식;황태용;한경호
    • 수산해양기술연구
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    • 제55권3호
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    • pp.233-242
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    • 2019
  • Species composition and yearly variation of fish eggs and larval fishes were investigated from 2014 to 2016. During the study period, the fish eggs were identified as belonging to 14 taxa. The dominant species of fish eggs were Leiognathus nuchalis, Engraulis japonicus, and Konosirus punctatus. These three species accounted for 97.4% of the total number of individuals collected. The collected larval fishes were identified into 37 taxa, 22 families, and seven orders. The dominant species of larval fish were Leiognathus nuchalis, and Gobiidae fishes. These three species accounted for 85.4% of the total number of individuals collected. The diversity index of the larval fishes was the highest in 2014 (H' = 1.60) and the lowest in 2015 (H' = 1.15). The evenness index was the highest in 2016 (J = 0.51) and the lowest in 2015 (J = 0.39). The dominance index was the highest in 2015 (D = 83.5%) and the lowest in 2016 (D = 70.9%). In addition, the economically important species in this area were Engraulis japonicus, Konosirus punctatus, Hippocampus coronatus, Sebastes schlegelii, Acanthopagrus schlegeli, and Cynoglossus joyneri.

Influence of Energy Restriction and Pre-incubation Holding Period of Eggs on Fertility and Hatchability in Aged Broiler Breeders

  • Shyam Sunder, G.;Vijaya Kumar, Ch.;Panda, A.K.;Rama Rao, S.V.;Raju, M.V.L.N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권2호
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    • pp.240-245
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    • 2010
  • The effects of controlled energy restriction and duration of pre-incubation egg holding on fertility, hatchability and hatch losses were evaluated in aged broiler breeders (64 wk). The energy (ME) required for maintenance, activity, growth and anticipated egg production was calculated and offered to a control group (283-471 kcal/kg) from 21-64 weeks of age. In three other groups, ME was quantitatively reduced either by 20% (SER; severe energy restriction) or 10% (MER; moderate energy restriction) and increased by10% (EEF; excess energy feeding) over the control group (CER; controlled energy restriction). Each diet was offered to 130 pullets in individual cages, and the quantity of ME increased with age. At the end of 64 weeks, fertile eggs were collected from each dietary group for 11 consecutive days and grouped under 4 holding periods based on the length of storage (2, 5, 8 or 11 d). The influence of energy regimes, egg holding intervals and their interaction was evaluated on fertility, hatch losses and hatchability. Broiler breeders maintained on SER regime (231-419 kcal/d) produced maximum number of eggs (993) followed by MER (819), CER (624) and EEF (438) during the 11-day period. The percent fertility and hatchability was significantly (p$\leq$0.05) higher in SER and MER groups compared to CER and EEF. However, energy regimes did not influence the loss in egg weight during pre-incubation storage, shell weight, shell thickness or hatch losses as dead germs and dead in shell. The improvement in hatchability in SER and MER groups appeared to be closely related to higher fertility and lower embryonic mortality. Holding of eggs for 11 days showed a linear loss in egg weight with the length of storage, but did not influence the fertility and hatch losses. The percent hatchability on eggs set was maximum when storage period was restricted to 5 days. The interaction between energy regimes and egg holding periods exhibited better hatchability results with SER regime when eggs were held for 5 days. Response to MER was not different from SER. It was obvious that energy restriction during production period had a positive influence on egg number, fertility and hatchability in aged breeders. At 64 weeks of age, holding of fertile eggs for 5 days prior to incubation was adequate for optimum hatchability in breeders.

귤응애에 대한 팔라시스이리응애의 포식특성 (Characteristics of Predation of Neoseiulus fallacis (Acarina: Phytoseiidae) on Panonychus citri (Acari: Tetranychidae))

  • 김동환;김상수;김광식;현재욱
    • 한국응용곤충학회지
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    • 제45권2호
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    • pp.145-152
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    • 2006
  • 감귤의 중요 해충인 귤응애의 생물적 방제를 위한 목적으로 귤응애에 대한 팔라시스이리응애의 포식특성을 조사하였다. 25$^{\circ}C$ 항온조건에서 귤응애의 알, 유충, 전약충, 후약충에 대한 팔라시스이리응애 암성충의 1일간 포식량은 각각 20.1, 26.1, 18.2, 7.4개체로 유충에 대한 포식량이 가장 많았다. 온도에 따른 포식량 조사결과, 온도가 높을수록 포식량이 증가하였으며, 이 때 팔라시스이리응애가 귤응애 알을 포식한 후의 출산능력(팔라시스이리응애 출산 알수/포식된 귤응애 알수), 즉 전환율은 10$^{\circ}C$를 제외하고는 0.09로 일정하였다. 잎 절편의 지름을 각각 20, 40, 60 mm로 하여 귤응애 알을 먹이로 공급했을 때 1일간 포식량은 각각 21.1, 17.3, 16.7개로 잎 면적이 증가할수록 포식량은 감소하였다. 또한 팔라시스이리응애는 귤응애 알, 유충, 약충을 먹이로 공급하였을 때 먹이밀도가 증가할수록 포식량은 점차 증가하였으나 그 증가율은 점차 감소하는 Holling의 기능반응 H형의 특성을 보였다. 이상의 시험결과 팔라시스이리응애는 귤응애의 생물적 방제 인자로서 가치가 있는 것으로 판단된다.

명주달팽이의 생활사, 인삼의 피해 및 약제 방제 (Life History, Ginseng Damage and Chemical Control of the Snail Acusta despecta sieboldiana)

  • 김기황
    • Journal of Ginseng Research
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    • 제16권2호
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    • pp.146-150
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    • 1992
  • Life history, ginseng damage, and chemical control of the snail Acusta despecta sieboldiana Pfeiffer were investigated in the field and laboratory conditions from 1987 to 1990. Eggs of the snail were whitish globular and 1.,93${\pm}$ 0.09 mm in diameter which were deposited as egg mass composed of 28.4${\pm}$ 15.4 eggs. Egg period was 11.8${\pm}$ 1.6 days under the laboratory condition. Most eggs were laid during mid July in the field. The snail had a life cycle of a year and hibernated from November to April. Significant ginseng damages by the snail (over 10% to the total number of plants) were observed only in the three to five year old ginseng fields with rice straw mulching. Based on the dates that the first ginseng damages were observed and on the questionary examination, ginseng damages seemed to occur from May to July. Metaldehyde (6%) bait showed reliable control effects on the snail.

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아카시나무에서 미국선녀벌레 알의 조사방법 (Monitoring Methods for Metcalfa pruinosa (Say) (Hemiptera: Flatidae) Eggs on Acacia Branches)

  • 최용석;황인수;이경주;나미숙;박덕기;서화영
    • 한국응용곤충학회지
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    • 제57권4호
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    • pp.297-302
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    • 2018
  • 우리는 미국선녀벌레의 월동알 조사를 하는데 있어 조사자의 공통된 조사방법을 제시하고자 전국적으로 분포하는 아카시나무의 가지를 부위별로 조사하였다. 조사한 총 표본수는 189개 샘플이었고 가지는 가시밑둥, 잔가지밑둥, 가지표면 세부분으로 나누어 알을 조사하였다. 모든 부위에서 알이 존재하지 않는 샘플을 포함했을 때는 모두 정규분포를 따르지 않았으나 알이 존재하지 않는 샘플을 제외했을 때는 가지밑둥과 잔가지밑둥에서 조사된 알은 정규분포를 따랐다. 가지의 굵기에 대한 정규성 정도는 없었다. 가지밑둥과 잔가지밑둥에서의 미국선녀벌레 알의 밀도는 가지표면에서 보다 유의성 있게 높은 밀도를 보여주었고 가지의 굵기별 조사에서는 유의성이 없었다. 따라서 미국선녀벌레가 주로 산란하는 아카시나무는 전국적으로 분포하고 있는 수종으로 아카시나무 가지의 굵기와 상관없이 가시밑둥과 잔가지밑둥에서 미국선녀벌레 알을 조사하는 것이 밀도 추정의 정밀도를 높여 정확한 한반도 분포 특성과 발생예측을 위한 조사방법으로 크게 기여할 것으로 판단된다.

Reproductive Performance of Breeds and Hybrid of Silkworm, Bombyx mori L. with Special Reference to Egg Laying Rhythmicity

  • Saha, Atul Kumar;Kumar, N. Suresh;Chakrbarty, Satadal;Patnaik, Bharat Bhusan;Nayak, Sandeepta Kumar;Roy, Subrata;Bindroo, Bharat Bhushan
    • International Journal of Industrial Entomology and Biomaterials
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    • 제26권1호
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    • pp.22-30
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    • 2013
  • The reproductive performance of multivoltine breed 'Nistari' and bivoltine breeds as NB18, P5 and a bivoltine hybrid (NB18 ${\times}$ P5) of B. mori were studied in different seasons in terms of total number of eggs laid, unlaid and hatching efficiency of the laid eggs to critically assess the breeds / hybrid potentiality. The bivoltine hybrid showed better performance in all the seasons as compared to the breeds investigated, as expected due to possibility of hybrid vigour. Among the breeds, bivoltine P5 had a better egg laid performance in S1 (February - March), S2 (May - June) and S3 (September - October) seasons but with an increase in the number of unlaid eggs. The hatching percentage, although didn't show any definitive trend, still suggested a marginal better performance in the hybrid. Most importantly, egg laying rhythmicity was studied by mating the female moth at 6.00 a.m. for $3{\frac{1}{2}}$ hours, and subsequently allowing the laying of eggs both under BOD condition ($25{\pm}1^{\circ}C$ and $85{\pm}5%$ RH) and at ambient temperature ($23-28^{\circ}C$ and $74.7{\pm}5%$) separately. Maximum (90%) egg laid occurred from 3.30 to 7.30 pm (i.e. 4 - 6 h after decoupling). Similar laying patterns were observed when females where mated at 12 noon and decoupled at 3.30 pm, revealing that late photoperiod and early scotoperiod were favourable for egg laying in case of multivoltine breed and bivoltine prefers late photoperiod for egg laying.

The Effect of Broodstock Age on the Spawning Performance of Cultured Haliotis discus hannai

  • Kim, Byoung-Hak;Kang, Kyoung-Ho;Zhang, Zhi-Feng;Kim, Jae-Min;Kim, Jan-Di
    • 한국패류학회지
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    • 제19권2호
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    • pp.107-110
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    • 2003
  • The effect of broodstock age on the spawning performance of cultured abalone, Haliotis discus hannai, was assessed for five age groups (3, 4, 5, 6, 7 years old). Spawning performance of the five age groups was assessed in terms of the percentage of spawning abalone, eggs per spawning female, fertilization rates, hatch rates and attachment rates per spawning. The percentage of spawning abalone increased along with broodstock age, reached maximum in female groups of 5- and 6-year age (60%), and in male group of 6-year age (100%), subsequently decreased in 7-year age group. The number of eggs produced per spawning also increased with broodstock age, and the maximum was found in 6-year age. Although the number of spawned eggs for the oldest abalone declined, it still spawned much more eggs than 3, 4, and 5 years old females. The fertilization and hatch rates were obviously larger for 4-6 years old group than the younger and older abalones. The maxima were found in 5-year age group (96.0% and 84.5%), and the minimum were appeared in 7-year age group (79.3% and 58.2%). The attachment rate increased with broodstock age, reached maximum in 6-year age group (33.6%), although the increment gradually declined. The attachment rate for 7-year age group rapidly decreased (16.6%). These results suggested that broodstock age affected the spawning performance of H. discus hannai, which peaked between 5 and 6 years old, and broodstock should be bred during this period for hatchery production.

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Oviposition Activity of Black Soldier fly (Hermetia illucens) under Artificial Illumination

  • Park, Kwan-Ho;Han, Moon-Hee;Lee, Seokhyun;Kim, Eun-Sun;Song, Myung-Ha;Kim, Won-Tae;Choi, Ji-Young;Kim, Hong Geun
    • International Journal of Industrial Entomology and Biomaterials
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    • 제35권2호
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    • pp.100-105
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    • 2017
  • Under natural conditions, black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), colonizes in warm temperate regions, and is active in Korea from May through October. Information on black soldier fly rearing, which is affected by seasonal factors in Korea, is limited. Oviposition by black soldier flies is dependent on light intensity and wavelength. Therefore, continuous mass rearing of this fly requires determination of optimal artificial conditions of illumination. In this study, we compared the number of eggs laid under an artificial light source (750 watt HPL lamp) versus nature sunlight. Our results showed that compared to oviposition under natural sunlight, the use of one or two lamps for 7 hours, resulted in only 43 and 76%, of the total number of eggs laid under natural sunlight, respectively. We also investigated the hatchability of oviposited eggs under artificial illumination and under natural sunlight. The hatching rate under the former was much significantly lower than under the latter. Further detailed research is required to develop methods for successful mass rearing of black soldier fly throughout the year by means of an indoor system.