• 한국수산과학회지
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• 제44권4호
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• pp.378-382
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• 2011

The feeding ecology of bluefin searobin Chelidonichthys spinosus around Jeju Island was examined. Specimens were caught every autumn from 2004 to 2007. The primary prey items of C. spinosus included fish, shrimp, and crabs. Chelidonichthys spinosus preyed upon a wide range of sub-pelagic crustacean groups(e.g., Leptochela gracilis, Leptochela sydniensis). This species was also an opportunistic feeder, exploiting the available prey groups in each area(i.e., L. gracilis in the South Sea and East China Sea groups and L. gracilis and L. sydniensis in the Yellow Sea group). The main prey group of this species changed from demersal shrimp to pelagic shrimp with prey environmental changes. Observed ontogenetic shifts in diet were relatively clear despite substantial overlap between the 10 cm and 20 cm C. spinosus groups.

• Fisheries and Aquatic Sciences
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• 제7권2호
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• pp.84-89
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• 2004

Feeding habits of Sillago japonica collected from in an eelgrass (Zostera marina) bed in Jindong Bay, Korea were studied. S. japonica was a carnivore which consumed mainly gammarid amphipods, polychaetes, bivalves, caridean shrimps and crabs. Its diets also included a small amount of fishes, copepods and caprellid amphipods. The diet of S. japonica underwent significant size-related changes; small individuals (<5cm SL) fed mainly on gammarid amphipods and crab larvae, while proportion of polychaetes and bivalves increased with increasing fish size and gammarid amphipods were also important prey for medium size individuals (5.1-9.9cm SL). The large individuals (>10cm SL) ate polychaetes, caridean shrimps and crabs. The dietary breadth of S. japonica were varied with size. The diet of S. japonica also underwent seasonal changes that could be related to differences in prey availability; gammarid amphipods were mainly consumed in spring and polychaetes in summer.

• 환경생물
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• 제21권4호
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• pp.328-336
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• 2003

Biological and ecological characteristics of Diporeia spp. are described including size, growth, life cycle, energy storage, temperature effect, bioturbation, feeding depth and sediment ingestion of Diporeia. Bioaccumulation and toxicity of organic contaminants and trace metals were reviewed in addition to an examination of the relationships among various condition indexes (i.e. wet weight, dry weight and body length) of Diporeia.

• Journal of Ecology and Environment
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• 제42권2호
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• pp.85-89
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• 2018

Observations and video documentation of interactions between animals living in dens, cavities, and other enclosed spaces are difficult, but they play an important role in field biology, ecology, and conservation. For example, bird parents visiting nests and feeding their nestlings may provide crucial information for testing of ecological hypotheses and may easily attract attention of participants of citizen-science ecological and conservation projects. Because of the nest concealment of cavity-nesting birds, their behaviors in the nest can only be studied by using video surveillance. Professional wildlife surveillance systems are extremely expensive. Here, we describe an inexpensive video setup that can be constructed with relatively little effort and is more affordable than any previously described system. We anticipate that the relatively low cost of about 250 USD for a battery-operated system is an important feature for citizen-science type of projects and for applications in heavily populated areas where the potential for theft and vandalism may be high. Based on our experiences, we provide methodological advice on practical aspects of using this system in the field for ecological research on birds. We highlight the low cost, easiness of construction, and potential availability to a large number of observers taking part in wildlife monitoring projects, and we offer technical help to participants of such research projects.

• The Korean Journal of Ecology
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• 제20권1호
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• pp.69-78
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• 1997

The development of stream ecology, especially the progress of that field in North America, has been briefly reviewed, and stream studies in Korea were analyzed through literature survey. During the last two decades, theoretical advances in stream ecology and understanding of the structure and function of stream ecosystem were made from the studies mainly in North America. Early studies (1960-1970) focused on determination of the environmental factors controlling the distribution and abundance of organisms dwelling in streams. Introduction of conceptual development, such as the functional feeding concept, river continuum concept, and nutrient spiraling was notable in the late 70's and the 80's. For last 20 years, experimentation approaches to apply ecological principles were very fruitful in the understanding of community structure. Even though studies on the stream ecosystem is Korea have a long history, most of works were concentrated on limited subjects: water quality, abundance and distribution of aquatic insects and fishes. Basic ecological attributes of stream organi는 and test of ecological principles have rarely been a subject of research topics. We must concentrate our effort to enhance our understanding of stream and river ecosystem through qualitative, experimental and interdisciplinary approaches.

• The Korean Journal of Ecology
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• 제20권1호
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• pp.9-14
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• 1997

Wintering behavior of mallards Anas platyrhynchos was studied from November 1995 to February 1996 at wintering habitats : Seosan reclaimed site, Oksan reservoir, and Kum river in Korea. The population of wintering mallards in maximum count was about 35, 000 at Sosan, 500 at Oksan and 1, 680 at Kum river, respectively. In Seosan area, mallards spent more time on water surface. In Kum river and Oksan reservoir, however, they spent more time in riversides. During the daylight hours, mallards spent more time in riversides and ground as the time passes by in the area. Behavioral patterns varied with habitat type, by days and months. Resting was a major time expenditure of mallards on water surface and riversides, and feeding occured occasionally on the ground. During the daytime, feeding and resting activities increased as time passed toward dusks However, time spendings for locmotion and comfort were decreased when it is close to the sun sets. Major disturbance factors within the habitats were identified the local traffics of humans, boats, aircrafts and motor vehicles. Among them, human was the most frequently affecting disturbance factor to the wintering mallards.

• 한국어류학회지
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• 제17권2호
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• pp.112-122
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• 2005

Iksookimia longicorpa was investigated in the upper part of the Seomjin River in Korea from 2003 to 2004. It inhabited pebble and cobble bottoms with water-current velocities of 10~30 cm/sec and depths of 30~100 cm. This species is active during daylight hours from March to October but hibernated in the river bottoms in the winter season. The sex ratio of female to male was 1 : 0.65, and the female was 20~40 mm larger than the male. Female length frequencies in this population indicated that the 65~90 mm group is 1+years old, the 90~110 mm group is 2+ years old, and the 110~130 mm group is 3+ years old. The males developed a secondary sexual character, the lamina circularis at the base of their pectoral fin, after 13~14 months. The spawning season was from early to middle June with water temperatures of $20{\sim}24^{\circ}C$ individuals became sexually mature after the age of 2 years. The average number of eggs in the ovaries was $2,402{\pm}944$. Stomach contents were mainly Chironomidae, Ephemeroptera, Arcellidae and Algae. The feeding rate was highest in April and September; they did not fed in the winter.

• Animal cells and systems
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• 제6권1호
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• pp.65-68
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• 2002

Female genital morphology of Cryptocercus Kyebangensis is described, focusing on the structural features of ovipositors at each developmental stage. Ovipositor valves were the first genital structures to appear in female nymphs. The caudal margin of the 9th sternum was nearly straight in the 1st instars of both sexes, with a slight median notch, but was deeply concave in the female nymphs of the End instar. The 1st valve of ovipositor budded off from membranous fold between the 8th 8nd 9th sternum and a pair of the 2nd valve came from the 9th sternum. Separation of styli occurred in the female nymphs of the 8th or 9th instar. Some parts of the female genitalia were sclerotized after the final molt. Spermathecae were the fork type and leaned a little to the right in the middle line of the genital chamber from ventro-posterior view. The trace sealed with sclerite materials existed on the spermathecal opening. The genital segments (segments Ⅷ, IX, and X) were concealed completely by the 7th tergum and sternum posteriorly expanded. Terminal lobes which exist in the Blattidae were not observed in C. Kyebangensis. Instead, the apicolateral emargination existed on the terminal abdominal segment of C. Kyebangensis females.

• 한국어류학회지
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• 제10권2호
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• pp.176-183
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• 1998

우리나라 주변 해역 중 심층에서 많이 출현하며, 생태학적으로 중요한 위치를 차지하는 앨퉁이(Maurolicus muelleri)의 산란생태 및 식성을 조사하였다. 앨통이는 동해 남부 연안역을 중심으로 연중 산란하며, 주 산란기는 8월 전후로 나타났다. 앨퉁이의 난소에서 관찰된 포란수는 5,072~32,117개 범위였다. 난경은 3개의 크기군으로 구분되었으며, 0.8mm 이상 크기의 난모세포가 산란된다고 볼 때, 1회 산란수는 약 250개로 추정되었다. 앨퉁이는 동물플랑크톤을 먹는 어류로 부유성 요각류(Copepoda)를 가장 선호하였으며, 그 외에 단각류(Amphipoda), 난바다곤쟁이류(Euphausiacea), 새우류(Caridea) 및 곤쟁이류(Mysidacea) 등의 갑각류를 잡아먹었다.

• Journal of Ecology and Environment
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• 제33권2호
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• pp.149-155
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• 2010

This study was conducted to investigate the feeding efficiency of the cattle egret (Bubulcus ibis) and the intermediate egret (Ardea intermedia) in relation to the stage of rice culture during two breeding seasons, 2006 and 2007, in Asan city, Chungcheongnam-do, South Korea. Cattle egrets caught mainly small invertebrate prey (insects and spiders, 98.4%) during all stages of rice cultivation, and had a higher prey capture rate in the plowing stage (14.98 prey/min) than in other stages (2.82-3.51 prey/min). Therefore, the biomass intake rate of cattle egrets was highest in the plowing stage. The intermediate egret captured both loaches (43.4%) and small invertebrates (50.6%). The prey capture rates of intermediate egrets increased gradually from the flooding stage (0.38 prey/min) to the planting stage (1.09 prey/min), and decreased in the growing stage (1.04 prey/min). However, intermediate egrets had the highest biomass intake rates in the plowing stage because more loaches were caught in the plowing stage (0.54 loaches/min) than other stages (0.23-0.36 loaches/min). Consequently, both intermediate egrets and cattle egrets had high energy intakes in the plowing stage and rice fields provided an important feeding habitat for both species.