• 한국수산과학회지
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• 제56권4호
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• pp.558-568
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• 2023

The spatio-temporal distribution of the sand crab Ovalipes punctatus larvae was investigated in the Korean waters in 2019. Sea surface temperature (SST) was the lowest in February and highest in September. Sea surface salinity (SSS) was the lowest in September and highest in March. Further, sea surface chlorophyll a (SSC) was the highest in September. Larvae were distributed in the South Sea and coastal area of Jeju Island from April to June, and the abundance was the highest in May. The spatio-temporal distribution analysis suggested that larval groups showed a tendency to be dispersed over a wider area as the larvae developed, due to the increase in their swimming ability. The correlation analysis between environmental factors and larval density suggested that larvae appeared in the SST range 11.8-20.9℃ and SSS range 31.5-35.3 psu. The Megalopal stage appeared in a wider range of SST and SSS than other larval stages, possibly due to the increased environmental tolerance before settlement. Results of redundancy analysis (RDA) and Spearman's rank correlation analysis between the larval density by developmental stages and the environmental factors suggested that SST showed a positive correlation and SSC showed a negative correlation in the later stage.

• 환경생물
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• 제36권2호
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• pp.140-149
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• 2018

진해만에서 출현하는 자어에 대한 계절별 군집 변동을 파악하기 위해 2015년과 2016년의 2월(겨울철), 5월(봄철), 8월(여름철), 그리고 11월(가을철)까지 계절별로 수행하였다. 조사기간 동안 출현한 자어는 종 수준까지 총 24과 28종이 출현하였다. 조사기간 동안 출현한 우점종은 청어 (Clupea pallasii), 꼼치(Liparis tanakae), 돛양태과 sp.(Callionymidae sp.), 청보리멸(Sillago japonica), 세줄베도라치(Ernogrammus hexagrammus), 그리고 멸치(Engraulis japonica)로 나타났으며, 이들 6종은 조사기간 중 출현한 자어 전체 출현개체수의 77.6%를 차지하였다. 우점종 중 청어와 꼼치는 2015년과 2016년의 겨울철에 출현한 반면에 청보리멸은 여름철에 출현하였다. 종 다양도 지수는 2월과 8월에 높았고 5월에 낮게 나타났다. 조사기간 동안 출현한 자어의 출현개체수를 바탕으로 nMDS 분석을 실시한 결과 계절에 따른 4개의 그룹으로 구분되었다. 본 연구결과 진해만의 자어 군집은 계절에 따른 수온변화와 산란에 참여하는 어종에 따라서 변동하였으며, 잠도와 칠전도 북부해역에서 높은 출현량을 보여 이 지역이 진해만의 주요 산란장으로 이용되고 있음을 의미한다.

• 한국수산과학회지
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• 제46권5호
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• pp.649-652
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• 2013

Distribution and migration of larval and juvenile sandfish Arctoscopus japonicus in the coastal waters off Gangwondo were determined monthly from samples collected by a rectangular bottom net in the coastal waters off Gangwondo from March to July, 2011. Fish were collected in abundance from the northern waters from March to June. The average total length (${\pm}SD$) was $11.5{\pm}1.6$ mm in March increased up to $53.5{\pm}3.3$ mm in June. The size distribution of sandfish by depth suggested that the fish grew waters less than 50 m deep until June, before moving deeper waters of around 100 m.

• 한국수산과학회지
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• 제44권5호
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• pp.516-523
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• 2011

To compare four populations of sea squirt Halocynthia roretzi adults, their egg quality and larval development were investigated in the hatchery. The populations were: south sea wild (SSW), south sea cultured (SSC), east sea wild (ESW) and Iwate Japan cultured (IJC). Egg quality and larval development were compared using 13 factors (fertilization rate and diameter, proximate composition, amino acid and fatty acid contents of eggs, hatching rate and various sizes of tadpole larvae) which were obtained from each population. Fertilized egg diameter, hatching rate and size of tadpole larvae were significantly different among the four populations (P<0.05). Eggs were produced with higher crude protein ($5.20{\pm}0.00%$ SSW, $4.71{\pm}0.01%$ ESW, $4.66{\pm}0.01%$ SSC and $3.96{\pm}0.01%$ IJC) and lipid ($1.22{\pm}0.01%$ ESW, $1.01{\pm}0.00%$ SSW, $0.77{\pm}0.01%$ SSC and $0.69{\pm}0.00%$ IJC,) contents from domestic wild populations than from Japanese or cultured populations. Also amino acid and fatty acid contents were different. The extent of similarity between domestic and Japanese populations (30.5% IJC:SSW, 34.3% IJC:SSC and 40.7% IJC:ESW) was relatively low but was very high between SSW and SSC (73.9%). These results may have been due to differences in the abundance of food types and environmental conditions in the four localities and consequent differences in the diets of the sea squirts.

• 대한수의학회지
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• 제30권4호
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• pp.499-505
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• 1990

The seasonal availability and abundance of the free-living stages of sheep nematodes is a key factor in the occurrence and severity of parasitic infection, and studies of larvae ecology could result in more rational control measures. In the present study seasonal pasture contamination and availability of nematodes for grazing sheep was examined as a baseline work for nematode control program at Namwon Branch, National Animal Breeding Institute during the period April 1988 through March 1989. Standard meteorological measurements were available from Unbong Sub-station, Honam Crops Experiment Station located about 200m from the experimental site. A total of 5 kinds of nematode larvae was detected: Haemonchus contortus was most prevalent (38.0%) with a decreasing order of Ostertagia spp (35.1%), Trichostrongylus spp (19.8%), nematodirus spp (6.6%), and Oesophagostomum spp (0.5%). A succession of species was recorded, in particular Ostertagia spp in May; Haemonchus contortus in June and July; Trichostrongylus spp in July and August; Nematodirus spp in August and September. These results can be incorporated into the nematode control program. To make a more rational control program, however, repeated herbage larval counts should be undertaken soil larval counts and fecal larval counts in the future.

• 수산해양기술연구
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• 제56권2호
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• pp.94-104
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• 2020

An ecological study for species composition and abundance of the fish assemblages in the coastal waters of Gujora and Mangchi of Geoje, Korea was conducted using monthly larval collection by an RN80 net from June, 2018 to May, 2019. A total of the 5 Orders, 15 Families, 21 species were collected. The dominant species were Ammodytes japonicus and Engraulis japonicas. Gobiidae was the most dominant species in June, Spratelloides gracilis in July, Chelidonichthys sp. in August, Gobiidae in September, Repomucenus beniteguri in October, Sebastiscus marmoratus in November, Sebastiscus marmoratus and Hexagrammos otakii in December of 2018, Pleuronectes yokohamae in January, Ammodytes japonicus in Febraury, Engraulis japonicus in March, Sebastes sp. and Gobiidae in April and Engraulis japonicus in May of 2019. The highest number of species and individuals were found in July and the smallest in August. Thus, the diversity index was the highest in July and the lowest in August. As a result of the similarity by month was divided into Group I in January and February and Group II in April, June and September. The most dominant species in the Group I were the Ammodytes japonicus and Sebastes inermis, and the most dominant species in the Group II was Gobiidae.

• 한국해양학회지
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• 제29권4호
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• pp.366-375
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• 1994

1991년 8월과 10월, 1992년 1월과 4월에 아산만의 30개 정점에서 채집된 동물플랑 크톤의 분포특성을 조사하였다. 동물플랑크톤의 출현 개체수는 240-1,458개체/m$^3$의 범위를 보였으며 요각류는 채집된 동물플랑크톤의 평균88%를 차지하여 가장 우점하였 다. Acartia bifilosa는 가을부터 봄에 걸쳐 우점 하였고, A. pacifica는 여름, Paracalanus parvus는 가을에 우점하였다. 동물플랑크톤의 수평분포는 식물플랑크톤의 분포와 밀접한 연관을 가져, 특히 식물플랑크톤의 출현개체수가 높은 봄에 높은 상관 관계 ($r^2$=0.66, p<0.01,n=30)를 보였다. 치자어의 출현개체수가 높은 여름에 동물플 랑크톤과 치자어의 수평 분포양상도 밀접한 관계를 가졌다. 동물플랑크톤의 출현개체 수에 의한 정점간 유사도를 집괴분석한 결과 본 해역은 내만과 외만으로 뚜렷이 구분 되었다.

• 한국응용곤충학회지
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• 제34권2호
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• pp.147-153
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• 1995

담배포장에서 담배나방의 발생은 조식 및 만식 재배구 모두에서 2 또는 3개의 뚜렷한 최성기를 보였다. 반면에 Campoleitis chlorideae는 담배 조식구에서는 담배나방의 두번째 최성기 직후 짧은 기간동안 발생하였으며 만식구에서는 담배나방 유웅이 존재하는 한 발생하였다. 만식구에서의 담배나방 발생은 조식구에서보다 많았다. 4가지 담배 품종중 NC-744에서 담배나방 유충의 발생이 비교적 컸다. 그러나, 기생벌의 발생은 Burley-21과 NC-82에서 많았다. 담배나방 유충의 포장에서의 인위적인 방사 및 재포획법에 의한 결과는 C. chlorideae의 활동은 6월말부터 9월초까지 보였으며 7월초 부터 8월말까지는 비교적 높은 밀도로 발생하였다. C. chlorideae의 담배나방에 대한 생물적방제 수단으로서의 가치평가를 위한 포장내 소규모 케이지 실험결과 방사밀도가 높을수록(암컷 4마리/2 $m^3$) 유충기생률이 높고(86.1%) 담배잎의 피해는 감소함을 보였다.(8.7%) 무처리구에서의 담배잎의 피해는 상당히 높았으며(23.2%) 살충제처리구에서 피해가 가장 낮았다.(1.6%)

• 한국해양학회지
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• 제19권1호
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• pp.44-55
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• 1984

아열대 seagrass 어류군집의 계절적 변동을 결정하기 위해, 미국 Texas 남쪽 해안에 위치한 Redfish Bay의 seagrass meadow에서 서식하는 소형어류개체군들의 밀도를 1982~1983년동안 매달 조사하였다. 23과 40종에 속하는 총 10223개체수가 채집되었으며, 평균밀도는 shoalgrass에서 약 15마리/$m^2$ 이었고 turtlegras 에서 약 6마리/$m^2$ 이었다. Darter goby, pinfish, code goby 그리고 Gulf pipefish가 일년을 통해 양 meadows는 우점종으로 나타났다. 이들 네 어종은 총채집된 개체수의 약 85%를 차지하였다. Darter goby는 얕은곳에 위치한 shoalgrass에서 가장 흔한 어종이었으며 약간,은 곳에 위치한 turtlegrass에서는 pinfish와 code goby가 가장 흔한 어종이었다. 어류의 종구성과 밀도의 계절적 변화는 이들 두 아열대 seagrass meadows에서 뚜렷하게 나타난다. 어류의 최대밀도는 봄에 나타난다. 어류밀도는 여름에 감소하나 가을에 다시 증가한다. 최소밀도는 겨울에 나타난다. 네 우점종은 각기 서로 다른 계절적 밀도변화 양상을 보인다. 이들 사이에는 약간의 중첩이 있지만 일반적으로 다른 종들로부터 1~3개월 분리된 최대밀도 시기를 보인다. 이같이 분리된 최대밀도 시기를 보이는 주요 어종의 계절적 개체수변화 양상은 높은 어류밀도를 지닌 아열대 seagrass meadows에서의 이들 주요 어종의 공존을 가능케하는 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.81-87
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• 2004

In order to investigate the effects of supplementary nutrients on silkworms, Bombyx mori, an experiment was conducted with ascorbic acid treatments. Dietary supplements of ascorbic acid 1, 2 and 3% were fed to silkworm larvae through 1st to 5th instar, The larvae were fed by mulberry loaves of Kokoso variety and the supplementary loaves were used once a day. These treatments resulted in a significant increase of biological parameters such as larval weight, the rate of food consumption and the approximate digestibility of the food. But the economical parameters such as cocoon weight and cocoon shell weight didnt show considerable difference compared to control. Dietary supplement of 2% ascorbic acid increased the larval weight by 7.8% and reached to 1.065g, which had the highest weight increase in the fourth day of 4th instar larvae. The percentage of daily weight increase in this group of larvae (79.01%) had significant difference compared with other treatments. The nutritional efficiency index in this group of larvae was better than others. Also the abundance of biochemical macromolecules such as glucose, cholesterol, triacylglycerol and urea in haemolymph of larvae fed by 2% ascorbic acid increased to become 29.75 (mg/㎗), 24 (mg/㎗), 75.4(mg/㎗) and 32.1(mg/㎗) respectively. But protein contents of haemolymph of larvae in each treatment were not significantly different. Since all the results achieved were not considerable either statistically or economically, this method could not be recommended to improve the sericultural parameters.