• Journal of Ecology and Environment
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• v.35 no.3
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• pp.189-194
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• 2012

Coarse woody debris (CWD) is generally considered dead woody material in various stages of forest decomposition and has been hypothesized to be an important habitat feature for mammals in forests of the Pacific Northwest, USA. Sherman and pitfall trapping were conducted for 2 years on three paired sites with low and high amounts of CWD. Deer mice was the dominant species with a total capture of 605 (45.6%). Four species of insectivores were captured, including Sorex moncicolus, S. trowbridgii, S. vagrans, and Neurotrichus gibbsii. A Poisson regression model was used to test whether 11 CWD variables could predict insectivore captures. The volume of logs and mean decay were important variables for deer mice use of CWD. Mean distance from pieces of CWD to the capture point was significantly related to the total number of captures of trowbridge shrew (Sorex trowbridgii) and all insectivore species. Vagrant shrews (Sorex vagrans) were significantly associated with log volume. Retaining large size CWD should be part of a management plan for ground-dwelling insectivores in forests to secure their biodiversity.

• Journal of Aquaculture
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• v.10 no.4
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• pp.387-394
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• 1997

A total of 353 farmed rockfish, Sebastes schlegli Hilgendorf, 1880 were sampled from 3 localities on Korean coastline over a 12 month period. Full parasitological examination revealed the polypisthocotylean monogenean Micorcotyle sebastis Goto, 1894 to be abundant with infections consistently reaching over 90~100% prevalence throughout the year. A seasonal pattern in parasite abundance on the gills is evident, with the population peaking twice, the largest in winter and again in summer. While the parasitic load on the left and right gills was not dissimilar, parasites within the gill sets were found to favour settlement of the II and III gill arches. A comparison of parasite abundance with host length, revealed that the smaller length fish classes (<17cm standard body length) had significantly heavier infections than those of larger fish (>17 cm standard body length). This report represents the fist record of Microcotyle sebastis on farmed rockfish in Korean coastal waters.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.192-203
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• 2018

Headwater streams provide various microhabitats, resulting in high diversity of macroinvertebrate community. In this study, we compared the differences of communities between two adjacent headwater streams (Jangjeon stream (GRJ; GRJ1-GRJ5) and Haanmi stream (GRH; GRH1-GRH3)) in Jungwang and Gariwang mountains, Gangwon-do and evaluated the effects of habitat condition to the macroinvertebrates community composition. In order to characterize the macroinvertebrate communities and extract influential environmental factors, we applied to Cluster analysis (CA), Indicator species analysis and Non-metric multidimensional scaling (NMDS). Total 33,613 individuals in 3 phyla, 5 classes, 13 orders, 51 families, and 114 taxa (genera or species) were collected. Gammarus sp. was dominant at the upper stream of GRJ, whereas Chironomidae spp. was abundant at GRH and the downstream of GRJ. The CA classified samples into six clusters (1-6) reflecting spatial and temporal variation of benthic macroinvertebrate communities. Benthic macroinvertebrate community composition was significantly different between two adjacent streams. Sweltsa sp. 1, Psilotreta kisoensis, Rhyacophila shikotsuensis and Serratella setigera were identified as representative indicator species for clusters 1, 2, 3 and 5, respectively. Similar to CA results, NMDS revealed the spatial and temporal differences of benthic macroinvertebrate communities, indicating the difference of community composition as well as microhabitat condition. Forest composition, proportion of boulders (>256 mm), and water velocity were main factors affecting the macroinvertebrate community composition.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.352-360
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• 2005

Acheilognathus signifer is distributed widely in high density in the Naechon-stream. The order of this-stream was 2 ${\sim}$ 4 and the water width is wide but the depth is relatively shallow and the sinuosity is 1.83, which indicates a meandering stream. The water width/stream width ratio is 1.59, which suggests moderate entrenchment. Naechon-stream was classed as B type by Rosgen (1995). The natural habitat of A. signifer is a slow flow velocity pool, like a backwater pool, which is made up of piled up boulders that restricts the flow of water. The stream bed is made up of boulders and sands that enable the spawning host to inhabit. A. signifer selects a microhabitat where the boulders furnish hiding places. The Habitat of A. signifer is strongly affected by the existence or not there of U. douglasiae sinuolatus. After hatching from the mussel, A. signifer inhabits the surface of the water. It then moves to the low layer once it acquires swimming ability. While A. signifer inhabits the river in summer, A. signifer moves to the deeper layers in winter, where there are the refuge like rocks and boulders. In spring A. signifer moves from the deep water to the river line where the mussels reside.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.193-204
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• 2014

The distribution of animals is affected by habitat selection, and habitat type and prey resource are important factors affecting their survival. This study was conducted to investigate the distribution pattern of the Red-tongue viper snake (Gloydius ussuriensis) with respect to altitude, habitat type and distribution of potential prey resource in Cheon-ma mountain, Korea. The study area of Cheon-ma mountain was separated into three altitude categories (low, middle, and high altitude) and the habitat types were categorized according to presence or absence of aquatic ecosystem and the preferred habitat in relation to altitude was determined. The distribution pattern of Red-tongue viper snakes was significantly different according to altitude and habitat type: they were mainly distributed at low altitude and in the water valleys. The distribution pattern of the Red-tongue viper snake correlated with that of amphibians. The analyses of microhabitat use of the Red-tongue viper snake and amphibians showed that their microhabitat types were not different significantly in water valleys. In conclusion, Red-tongue viper snakes were mainly distributed in the water valleys at low altitude and this is because amphibians are important as potential prey of the Red-tongue viper snake in Cheon-ma mountain.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.2
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• pp.100-116
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• 2002

There are several purpose to introduce microorganism into the Soil. The major purpose is to promote plant growth and inhibit plant pathogens. The model example is to put in nitrogen fixing symbiotic bacteria, Pythium and Rhizobium. In order to achieve the intended goal, the introduced microorganism should survive and colonize with sufficient density. The survival of introduced microorganism depend upon biotic and abiotic factors. Predation and competition are important among biotic factor. Water tension, organic carbon, inorganic nutrients(N, P), pH are important factor among abiootic factor. Soil texture and distribution of soil pore are also important in the survival and colonization of introduced microorganism. Selection by soil ecosystem for inoculant is a crucial factor for colonization. Good example are control of autochtonous microorganism and the introduction of surfactant biodegrading Pseudomonas. Sometimes, carriers such as peat and montmorillonite can be added to help colonization. Carriers can protect introduced microorganism by supplying protective microhabitat. Organic polymer is also used as a carrier to immobilize bacteria or industrial enzymes. Examples of these carrier are calcium alginate, agarose and k-carrageenan. The function of these carrier is to provide microhabitat and help colonization for introduced microorganism.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.113-116
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• 2000

Different phenological patterns of leaf and fruit fall among native and non-native riparian species provide a spatially and temporally heterogeneous series of alternative food resources for detritivores. Relatively little is known about qualitative differences among these different riparian species. Rates of litter inputs, decomposition, and retention for different sources of riparian litter require long-term documentation. Species of freshwater shrimps, crabs. insects. and gastropods are known to consume a wide range of litter inputs but how these dynamic food webs function under changing climatic and land-use conditions is unknown, especially in tropical streams. On-going studies in the Luquillo Experimental Forest. Puerto Rico provide an example of how inputs of fronds and fruits from palms (Prestoea montana) serve as important foods and microhabitat for species of freshwater crabs and shrimp. Native riparian species such as Prestoea montana are commonly distributed in the Luquillo Mountains especially along steep slopes and stream banks. After tropical storms with high winds, the large fronds from these native riparian trees provide important inputs of leaf litter to the stream food web. In some streams, the input of ripe fruit from non-native trees such as Java plum (Syzigium jambos) also provides a major source of detrital food resources, especially during periods when fruit fall from native species of palms may be limited.

• Applied Microscopy
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• v.46 no.1
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• pp.51-57
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• 2016

The histology and anatomy of the olfactory organ in Luciogobius guttatus was investigated using a light microscopy and scanning electron microscopy. The paired olfactory organs in the dorsal part of the snout are situated in between the upper lip and the eyes. They consist of two nostrils, one anterior and the other posterior openings, and a single olfactory cavity. The anterior nostril, an incurrent opening, forms a short tubular structure from the skin. The posterior nostril, an excurrent opening, forms a circular structure opened to the exterior. The distributional pattern of the sensory epithelium is a continuous type. The sensory epithelium with numerous-motile cilia is made up of receptor cells, supporting cells, basal cells, and mucous cells. In contrast, the non-sensory epithelium is comprised of stratified epithelial cells and two types of mucous cells, acidic and neutral cells. The cilia number of the receptor cell is in range of 3 to 4 units. Such results in L. guttatus may reflect its ecological habit and microhabitat in the tidal zone with a periodic tide.

• Animal cells and systems
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• v.4 no.2
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• pp.109-115
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• 2000

To clarify taxonomic status of the two sibling species, Moroco oxycephalus and M. lagowskii reproductive isolation mechanisms were investigated at sympatric area located in Kansung-up, Kosung-gun, Kangwon-do, Korea. Genetic analysis was performed to reveal mating system and intensity of Hybridization between the two species. The frequencies of hybrids were increased since 1989, and then the observed hybrid frequencies ($H_O$) did not significantly differ from the expected hybrid ($H_E$) in 1998 and 1999. However, based on histological analysis of two parents and their hybrid s gonads, the hybridizations between M. oxycephalus and M. lagowskii produced mostly fertile females but sterile males in accordance with Haldane s rule. Although it was suspected that pre- and postmating isolation mechanisms were affected between the two species, M. oxycephalus and M. lagowskii seemed to be strongly isolated with microhabitat at sympatry until 1997. Since 1998, hybrid frequencies were increased by habitat disturbance. However, their hybrid frequencies would be reduced by postmating isolation mechanisms. Therefore, the two species are considered to be distinct species recently diverged.

• Animal cells and systems
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• v.16 no.4
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• pp.343-349
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• 2012

A variety of fish species undergo an ontogenetic change in prey selectivity, and several potentially interacting factors, including nutrient requirement, microhabitat change, and foraging ability, may account for the occurrence of the shift. Here we examine the foraging ecology and ontogenetic diet shift of a micro-carnivorous goby, Pterogobius elapoides (serpentine goby), dominant component of fish assemblage in shallow rocky areas off the coast in Korea and Japan. Although most other gobies are primarily benthic carnivores, P. elapoides is a semipelagic fish; however, little is known about how those species change their foraging tactics with growth. In our diet analyses, the most common diet was pelagic copepods and benthic amphipods, and diet shift was observed from pelagic to benthic with growth. The ontogenetic diet shift seems to be the result of the preference for energetically more profitable prey in larger-size classes as well as the results of different prey availability due to among-habitat variation in diet. However, differential food preference does not appear to affect individual scope for searching food. Several factors such as predation pressures and interspecific resource partitioning might contribute to the changes in diet observed among size classes, which were included in our ongoing tests.