• Journal of Wetlands Research
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• v.15 no.1
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• pp.19-24
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• 2013

To assess on the biological control potential with the native fishes, Aphyocypris chinensis, Oryzias sinensis, Misgurnus mizolepis, Pseudorasbora parva, Carassius auratus, Odontobutis interrupta were tested in relation to optimal condition controling mosquitoes in Seosan region. As a result of larvivorous activity for predation rate and temperature difference along kinds of native fishes, predation rate of Aphyocypris chinensis was the highest and predation rate of Misgurnus mizolepis was the lowest under the $23^{\circ}C$. Contrastively, predation rate of Aphyocypris chinensis and Odontobutis interrupta was the highest in least time. Predation rate of Misgurnus mizolepis was the lowest under the all temperature among six species fishes. Aphyocypris chinensis and Pseudorasbora parva in low, Carassius auratus, Misgurnus mizolepis and Odontobutis interrupta in bottom appeared high predation rate along the water depth. And predation rate of Oryzias sinensis was high as 95% at surface. As a result of measuring time taken to predate 50 mosquito larvae by 3 species fishes, two Aphyocypris chinensis took 10minutes, two Oryzias sinensis took 21min., two Misgurnus mizolepis took 45min. But one Aphyocypris chinensis and Misgurnus mizolepis took 8min., one Misgurnus mizolepis and Oryzias sinensis took 17min.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.406-413
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• 2023

Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours.

• Journal of the korean society of oceanography
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• v.31 no.3
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• pp.144-149
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• 1996

I investigated the predation impact by the heterotrophic dinoflagellate Protoperidinium cf. divergens on copepod eggs in the presence of co-occurring phytoplankton prey (a preferred red-tide dinoflagellate Gonyaulax polyedra) and the selective feeding on mixtures of both prey. The ingestion rates of P. cf. divergens on Egg N (unidentified round copepod eggs with a smooth surface, about 80 in diameter) decreased by only 1.7-2 times when mean G. polyedra concentration increased by 57-115 times. In mixed prey experiments, P. cf. divergens preferred Egg N over G. polyedra even at 1.1 ${\mu}g$C $ml^{-1}$ or 470 cells $ml^{-1}$ of the latter. A strong preference of P. cf. divergens for Egg N over G. polyedra can be responsible for this relatively small effect. Protoperidinium may sometimes have a considerable predation impact on the populations of Egg N even during phytoplankton blooms or red-tide periods.

• Animal Systematics, Evolution and Diversity
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• v.14 no.2
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• pp.159-164
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• 1998

The spider, Tetragnatha squamata and its prey Empoasca vitis, the tea leafhopper, were investigated in laboratory on the prey-predator relationship. The predator spider showed a significant response to the increase of the prey. The predation effiency and the response of predator to its density were examined as well. The result of the experiments are give as questions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.1
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• pp.40-49
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• 2004

An ecological study on a sea urchin population, Strongylocentrotus nudus, a key role species in recovery of macroalgal bed, was conducted in Hosan, Samcheok area on the east coast of Korea. Three experimental plots, namely, AMB (artificially-restored macroalgal bed), BG (barren grounds) and NMB (natural macroalgal bed) were established after a pilot survey in June 2002. Distribution and abundance, grazing rates, predation pressure and predator guilds on S. nudus were estimated in three plots bimonthly from Aug. to Dec., 2002. Abundance of S. nudus was lowest, but median test diameter of the urchin was highest (Kruskal-Wallis test, p-value, p<0.001 in Aug. and p=0.003 in Oct.) in NMB In-situ grazing rate of S. nudus estimated by enclosure cage experiment in NMB was about 12 times higher in Aug. (160.0 mg seaweed/g sea urchin/day) than in Oct. (13.8). Predation intensity measured by tethering experiment was higher in NMB. Most of the predators on S. nudus were invertebrates and no fish predators were found. Predator guilds identified by the fish trap experiment using live or dead sea urchins included who]ks Neptunea arthritica, starfish Asterina pectinifera, hermit crabs Pagurus of. samuelis, Paguristes barbatus, brown shawl crabs Atergatis integerrimus and crabs Actaea subglobosa. High predation pressure on S. nudus in natural macroalgal beds was the likely cause of its low density. Elevated sea urchin density and the consequent lasting deforestation of macroalgae in barren grounds demonstrate the importance of predation pressure on sea urchins.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.44-49
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• 2001

Development and predation of an aphidophagous gall midge, Aphidoletes aphydimyza (Rondani) , on the green peach aphid, Myzus persicae Sulzer, were studied under laboratory and greenhouse conditions. The developmental threshold temperature of the gall midge larvae was estimated to be $13^{\circ}C$. Larval and total developmental periods were 5.3 and 29 days at 25 $\pm$$2^{\circ}C$. The gall midge attacked more aphids as increasing density of peach aphids, and consumed 4 out of 10 peach aphids per day in a petri dish (9 cm in diameter) at maximum. In green house, the gall midge could control the density of the green peach aphids efficiently with a delayed density dependent-like pattern.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.61-67
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• 1993

Experiments were conducted to study the functional response of Amblyseius longispinosus Evans to egg densities (10-80) of Tetranychus urtica Koch under different egg distributions (clumped & uniform) and arena sizes (3, 9 & 16 $cm^2$). The searching success of A. longispinosus was affected by the spatial distribution and density of the prey but not by the arena size. there was a highly significant negative correlation (r=-0.85; p=0.0001) between predation amount and distances between preys. The predation response showed a type III functional response. The random predator equation satisfactorily described A. longispinosus predation. The search rate ranged from 0.1030 to 0.1504 under distribution of the prey while it ranged from 0.0546 to 0.276 under uniform distribution.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.336-341
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• 2006

The biological wastewater treatment system is known to have an important role in reducing the quantify of enteric virus in water environments. To clarify the roles of activated sludge microbes in decreasing the virus infectivity, the behavior of the virus in bacteria, protozoa, and metazoa was examined by pure or mixed culture system using poliovirus type 1(Lsc, 2ab strain). In the bacterial culture systems, the virus infectivity in the liquid phase decreased by a reversible adsorption of the virus to the bacteria or bacterial flocs. On the other hand, in the protozoa and the metazoa culture systems using T. pyriformis and P. erythrophthalma, respectively, with a variety of bacterial strains as prey, the main virus decrease mechanism of reversible adsorption in early stage was changed to irreversible predation, which was not eluted in this study. The virus decrease was more effective in the P. erythrophthalma culture system, which had high predation and floc forming abilities. However, in the mixed culture system of Z. ramigera and P. erythrophthalma, the more rapid reversible adsorption of virus to Z. ramigera flocs preceded the irreversible predation of P. erythrophthalma.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.265-274
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• 1997

All landscapes are mosaics of habitat patches of different types. Therefore, there are always edged between habitat patches in a landscape. Forest animal has an important role in vegetation development and maintenance by seed dispersal around forest. Movement of animals depends on the spatially heterogeneous structure and pattern of vegetation landscapes because each animal has special habitats in a landscape. Especially, forast edge with high permeability and prey density is one of the important habitats to the animals. Therefore, understanding the ecological characteristics of the forest edges as a corridor connecting mosaic vegetation patches is necessa교 새 establish the strategies for the nature conservation and sustainable vegetation management. Under this idea, we examined the animal influenced on pine seeds as one of the method of monitoring the animal activity in mosaic vegetation. Man-made mosaic vegetations including open, edge and inner forests were carefully selected in the rural landscape. We carried out predation test on pine seeds during one year. A result was that damages on seed was more significant at forest edge than inner and open forest. Pine seed on seedbeds was mainly attacked by squirrels and mice than birds. Pine seed was damaged by squirrels in different types of vegetation by seasons. Rate of seed predation at forest edge was, in special, higher than that of other sites. According to this results, it is suggested that the relationship between animal behavior and spatial vegetation structure relating to human impact such as the distance from settlement to vegetation appeares to be in the rural vegetation landscape.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.130-136
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• 2004

In the present study, prey preference of juvenile fishes was examined using an experimental approach. Zooplankton composition, as a prey of the fish, was evaluated by taking into account the species as well as body size of juveniles in the aquarium. The predation of juvenile fishes is known to be an important factor in changes of zooplankton communities. In some previous studies at the regulated Nakdong River, the collapse of large cladcoerans and an increase in the rotifer population by selective predation during spring and summer were observed. This study focused on the predation of juvenile fishes such as Hyporhamphus sajori, Rhinogobius brunneus, and Opsariichtys uncirostris amurensis on zooplankton community structure in mesocosm scale experiments. These fishes selected the cladoceran Moina micrura with highest individual preference value (Manly/Chesson index)among zooplankton prey in the experimental aquarium. When the size-selective prey preferences of the juvenile fish were compared, both small (body size <2 cm) and large (body size >2cm) juveniles of O. uncirostris positively selected M. micrura. In the outdoor experimental tanks, juvenile fishes consumed the cladoceran M. micrura, resulting in an high abundance of the rotifer, Polyarthra spp. The results suggest that juvenile fish predation may play an important role in regulating the zooplankton community structure by reducing the cladoceran density and increase of rotifers in the Nakdong River during spring and summer.