• Journal of Fisheries and Marine Sciences Education
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• v.23 no.1
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• pp.35-42
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• 2011

Behaviour habitats of sailfin sandfish, Arctoscopus japonicus, one of the stock recovery species of Korea, were investigated when they were approaching toward the eastern coastal waters of Korea during spawning season. Underwater surveys were conducted in December, 2009 at Jug-island, Goseong, Gangwon-province to observe the behaviour of sailfin sandfish by underwater video camera and underwater camera, and the body characteristics of sailfin sandfish caught by gillnet were measured. It was observed that the species generally move in school but a few of individuals go out of the school to approach and dig into the sand bottom. Eggs of sailfin sandfish were shown in many cases to be attached to seaweed like Sargassum fulvellum and Zostera mairna. The females maintain its body in horizon and shake the body to breed eggs. It was also observed that the males spray sperm on the eggs attached on seaweed. Sailfin sandfish is assumed to make diurnal migration by moving to the shallow coast at night for spawning and fertilization, and moving out to the offshore at sunrise.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.322-332
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• 2013

This study was conducted to understand the control mechanism of Sika deer (Cervus nippon taiouanus) populations which are adapted to the natural forest areas and the semi-natural forest areas of Korea. We monitored and analyzed the behaviour patterns and habitat characteristics of Sika deers. After we released 12 Sika deers (male 3, female 9) each at the two study areas in and around Seoul under the approval of Korean government, we monitored them through our survey researchers' naked eyes from May 2011 to January 2012. We discriminated their habitat patterns to 4 major places - eating food place, drinking water place, daytime rest place, and nighttime rest place. Our results showed that Sika deer preferred the open grassland habitats for feeding and resting in daytime but the closed bushland for their protection and sleep. We also found the recommended sex ratio of adult male to female in a herd was 1 : 4~9 for breeding and they had few cubs in a herd. The average amount of food for 1 adult deer was 391.62 kg of fresh grasses and 286.90 kg of hay per year. Our results suggest that the amount of drinking water required for a deer when grazed on grasses during spring and summer seasons is 256.8 L and when a deer feeds on dry food during autumn and winter seasons, 209.8 L of water is required. From these results, we observe that the amount of drinking water was affected substantially by the moisture content of their food. This observational study must be very valuable for land managers to judge the number of deers that should be released in natural areas without high risk and to ascertain the sex ratio of large mammals including Sika deer. Therefore, we conclude that this population control mechanism study consists of efficient basic data and their values must be very effective for various purposes.