• Title/Summary/Keyword: Aquarium

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Convergence Approach of the Marine Tourism Policy (해양관광 정책의 융복합적 접근에 관한 연구)

  • Lee, Jung-Chul
    • Journal of Digital Convergence
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    • v.15 no.2
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    • pp.233-238
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    • 2017
  • The purpose of this study is to investigate the necessity of policy approach in terms of complex combination of tourists and fishing villages. In order to achieve the purpose of this study, the policies related to the marine tourism industry were investigated and the laws related to the development of the coastal area and fishing port area were investigated. As a convergence approach to marine tourism policy, First, the development of marine tourism resources should be based on the increase of hydrophilic activities and the characteristics of the four seasons. In particular, the need to dig through support of projects such as the successful model that made aquarium associations etc. that are currently in progress, such as "fishing village experience".

Case report: Mass mortality of olive flounder (Paralichthys olivaceus) caused by acute gas bubble disease

  • Lee, Yoonhang;Kim, Nameun;Lee, Ju-yeop;Kang, Hyoyeong;Sung, Minji;Yu, Young-Bin;Kim, Kyunghoi;Je, Jae-Young;Kim, Hyun-Woo;Kang, Ju-Chan;Kim, Do-Hyung
    • Journal of fish pathology
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    • v.34 no.2
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    • pp.255-259
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    • 2021
  • This is the first report describing acute mass mortality occurred in juvenile olive flounder (Paralichthys olivaceus) caused by gas bubble disease (GBD). A total of 610 fish (average weight = 35 g), which were more than half of the fish acclimated at 17℃ in an aquarium, were killed within two days of acclimation. The dead and moribund fish showed excessively opened opercula and mouths, and occasionally, severe exophthalmia. Through microscopic observation, numerous gas emboli were found in the gills of the dead and live fish, while the fish were not infected with any microbial pathogens. The dissolved oxygen (DO) saturation level of the rearing water and seawater nearby the facility reached 145% and 286%, respectively, whereas other water quality parameters (such as salinity, pH, and chemical oxygen demand) were normal. The extreme saturation rate of seawater in the shore nearby seemed to be due to an enormous algal bloom that occurred there. Through molecular identification based on 18S rDNA sequences, the most dominant algal species was most closely related to Ulva californica (99.87% sequence identity) followed by U. prolifera, U. linza, and U. curvata (99.81%). Therefore, it can be concluded that supersaturated seawater due to mass algal bloom caused gas bubble disease in the olive flounder, leading to mass mortality. After technical adjustment, such as increased aeration, lowered water circulation rate, and inlet water filtration using micro-pore carbon filters, the DO level became normal, no further mortality occurred and the status of the fish was stabilized.

The Spawning Behaviour of the Endangered Freshwater Fish Koreocobitis naktongensis (Cypriniformes: Cobitidae) under Artificial Conditions (멸종위기어류 얼룩새코미꾸리 Koreocobitis naktongensis (Cobitidae)의 수조 내 산란행동)

  • Hong, Yang-Ki;Yang, Hyun;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.33 no.1
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    • pp.15-21
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    • 2021
  • The Nakdong nose loach, Koreocobitis naktongensis is an endangered freshwater fish endemic to Korea. The spawning behaviour of the K. naktongensis was observed after treating Ovaprim in laboratory aquarium from 20~27 April 2010. The behavioral patterns were categorized into three stages of pre-spawning, spawning and post-spawning behaviors. Before spawning K. naktongensis usually repeated taking a rest and swimming. On average, initial spawning activity started 11 to 12 hours later after injection with Ovaprim. During the spawning period, the number of spawning acts ranged from 1 to 18. The spawning ratio of female to male was 1 : 1. The male embraced the back of the female's dorsal fin with his lamina circularis. It looked like a complete circle at that time. After spawning, parental care was not observed. Individuals not participating in spawning have been observed to feed on some of the fertilized eggs.

A Research on the Waiting and Resting Behaviors of Children in the Outpatient Clinic of a Children's Hospital - Focused on the Comparative Analysis between Children with and without Disabilities - (어린이병원 외래진료부 이용자의 대기 및 휴게행태 연구 - 장애 및 비장애 어린이의 비교 분석을 중심으로 -)

  • Cho, Min-Jung
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.33 no.12
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    • pp.41-52
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    • 2017
  • This study investigates the waiting and resting behaviors of children within a restorative healthcare facility design. In particular, the aim is to compare children with and without disabilities and reveal similarities and differences in terms of their behavioral characteristics and uses of design facilities, related to positive distraction, for restoration in the hospital. Three major common spaces for outpatients in S children's hospital in Seoul were examined including the main lobby and two waiting and resting spaces in the pediatric and rehabilitation medicine departments, respectively. A total of 155 children under the age of 12-67 with physical disabilities and 88 without-were observed while they waited and rested at the three spaces before or after doctors' examination. Basic demographic information and waiting and resting behavioral characteristics were compared between the two groups. The results indicated that the disabled children were more restricted in terms of space, facilities used, and social behaviors. However, regardless of disabilities, the children showed more positive distractions related to cognitive and social behaviors in areas where restorative design elements such as an aquarium, garden, or visual images were available. Based on the results, design implications were discussed to strengthen positive distraction behaviors in children with and without disabilities and to foster the restorative quality of the spaces for waiting and resting in the children's hospital.

Analysis of the Rate of Post-Hatching Growth of the First Artificially Bred Green Turtle Chelonia mydas Juveniles in Korea (국내최초 푸른바다거북(Chelonia mydas)의 실내 인공 번식 및 어린 개체의 초기 성장 특성)

  • Cho, Eunvit;Kim, Il-Hun;Han, Dong Jin;Im, Jien;Cho, In Young;Lee, Ki-Young;Moon, Dae Yeon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.6
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    • pp.917-926
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    • 2022
  • The green turtle Chelonia mydas has been designated as an endangered species globally due to its reduced population. Although C. mydas is not known to reproduce on the shores of the Korean peninsula, it has been listed as a protected marine species in South Korea. This study describes the first successful captive breeding of C. mydas in a commercial aquarium in South Korea and provides information on the early growth patterns of C. mydas hatched and reared in indoor facilities. C. mydas YS-B003 laid a total of 594 eggs in ten nesting events in the period December 2016-June 2017. Of these, 115 fertilized eggs from six events hatched successfully. The size of the newly hatched turtles differed significantly among nesting events. The hatchlings from the 8th and 9th nesting events were relatively smaller than those from the 3rd and 5th events. The rate of growth initially varied across the different events, but from the 1,000th day, the inter-group variation disappeared. The present study provides useful information for future captive breeding of sea turtles in indoor facilities, which would contribute to the protection of these endangered sea turtle species.

New records of two alien plants, Juncus torreyi (Juncaceae) and Egeria densa (Hydrocharitaceae) in Korea

  • Jongduk JUNG;Hye Ryun NA;Kyu Song LEE;Yeongmin CHOI;Woongrae CHO;Jin-Oh HYUN
    • Korean Journal of Plant Taxonomy
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    • v.53 no.1
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    • pp.54-59
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    • 2023
  • Naturalized populations of two alien plants were newly found, and we describe their morphological characteristics and habitats with photographs. One is a member of Juncaceae, Juncus torreyi Coville, and was newly found at a pool of a beach in Gangwon-do. This rush is native to North America and belongs to the sect. Ozophyllum (subgen. Juncus) according to certain morphological characteristics, such as its racemose inflorescence, the absence of floral bracteole, and unitubular leaves with perfect septa. J. torreyi is easily distinguishable from Korean rushes by its long rhizomes with swollen nodes and globular head with 25-100 flowers. Its introduction into Japan and Europe was reported, but the ecological risk associated with its over-dispersal is not known. The other alien plant is a submerged plant, Egeria densa Planch. (Hydrocharitaceae), which was found in streams in Gyeongsangbuk-do and ditches in the Busan-si area, both of which being in the watershed of the Nakdong River. Egeria densa is similar to Hydrilla verticillata (L.f.) Royle, which is native to Korea. However, it is distinguished from H. verticillata by its larger flowers and lack of overwintering organs. This alien plant is native to South America and was introduced for aquarium gardening and naturalized around the world. Egeria densa is treated as a malignant weed due to its asexual reproduction and rapid growth. Size changes and the number of populations of E. densa must be investigated.

Dihydroaustrasulfone alcohol induces apoptosis in nasopharyngeal cancer cells by inducing reactive oxygen species-dependent inactivation of the PI3K/AKT pathway

  • Kok-Tong Tan;Yu-Hung Shih;Jiny Yin Gong;Xiang Zhang;Chiung-Yao Huang;Jui-Hsin Su;Jyh-Horng Sheu;Chi-Chen Lin
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.4
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    • pp.383-398
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    • 2023
  • Dihydroaustrasulfone alcohol (DA), the synthetic precursor of a natural compound (austrasulfone) isolated from the coral species Cladiella australis, has shown cytotoxic effects against cancer cells. However, it is unknown whether DA has antitumor effects on nasopharyngeal carcinoma (NPC). In this study, we determined the antitumor effects of DA and investigated its mechanism of action on human NPC cells. The MTT assay was used to determine the cytotoxic effect of DA. Subsequently, apoptosis and reactive oxygen species (ROS) analyses were performed by using flow cytometry. Apoptotic and PI3K/AKT pathway-related protein expression was determined using Western blotting. We found that DA significantly reduced the viability of NPC-39 cells and determined that apoptosis was involved in DA-induced cell death. The activity of caspase-9, caspase-8, caspase-3, and PARP induced by DA suggested caspase-mediated apoptosis in DA-treated NPC-39 cells. Apoptosis-associated proteins (DR4, DR5, FAS) in extrinsic pathways were also elevated by DA. The enhanced expression of proapoptotic Bax and decreased expression of antiapoptotic BCL-2 suggested that DA mediated mitochondrial apoptosis. DA reduced the expression of pPI3K and p-AKT in NPC-39 cells. DA also reduced apoptosis after introducing an active AKT cDNA, indicating that DA could block the PI3K/AKT pathway from being activated. DA increased intracellular ROS, but N-acetylcysteine (NAC), a ROS scavenger, reduced DA-induced cytotoxicity. NAC also reversed the chances in pPI3K/AKT expression and reduced DA-induced apoptosis. These findings suggest that ROS-mediates DA-induced apoptosis and PI3K/AKT signaling inactivation in human NPC cells.

PredFeed Net: GRU-based feed ration prediction model for automation of feed rationing (PredFeed Net: 먹이 배급의 자동화를 위한 GRU 기반 먹이 배급량 예측 모델)

  • Kyu-jeong Sim;Su-rak Son;Yi-na Jeong
    • Journal of Internet Computing and Services
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    • v.25 no.2
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    • pp.49-55
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    • 2024
  • This paper proposes PredFeed Net, a neural network model that mimics the food distribution of fish farming experts. Unlike existing food distribution automation systems, PredFeed Net predicts food distribution by learning the food distribution patterns of experts. This has the advantage of being able to learn using only existing environmental data and food distribution records from food distribution experts, without the need to experiment by changing food distribution variables according to the environment in an actual aquarium. After completing training, PredFeed Net predicts the next food ration based on the current environment or fish condition. Prediction of feed ration is a necessary element for automating feed ration, and feed ration automation contributes to the development of modern fish farming such as smart aquaculture and aquaponics systems.

Performance of growth on Trachinotus blochii larvae fed by Brachionus plicatilis enriched with eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA) extraction from Maggot black soldier fly (BSF)

  • Indra Gumay Yudha;Maulid Wahid Yusup;Muhammad Kholiqul Amiin;Linda Ratna Sari;Diep Minh Luc
    • Fisheries and Aquatic Sciences
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    • v.27 no.9
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    • pp.634-643
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    • 2024
  • Silver pompano (Trachinotus blochii) is one of the major commodities of the aquaculture industry in Lampung. Silver pompano hatchery activities that still require natural feed, namely Brachionus sp. Brachionus plicatilis is a filter feeder that does not filter selectively all available feed, so an enrichment process is required so that natural feed reproduces with high nutritional content and is high in fatty acids (eicosapentaenoic acid [EPA] and decosahexaenoic acid [DHA]). This study aims to determine the best survival and growth of silver pompano larvae by feeding B. plicatilis enriched with EPA and DHA fatty acids derived from maggots black soldier fly (BSF). Five-day-old silver pompano larvae with a density of 20 larvae/tank in a 20 × 20 × 20 cm aquarium container. B. plicatilis was fed at a density of 13 ind/mL. Nannochloropsis salina was also given as additional feed at 300-400 cells/mL density. We gave B. plicatilis three times a day (05:00 am, 02:00 pm, and 9.00 pm) for 30 days of cultivation. The experimental treatments were A (no enrichment), B (100 ppm), C (300 ppm), D (500 ppm), and E (700 ppm). The conclusion of this study is the provision of EPA and DHA oil from maggot BSF with different doses of rotifer enrichment has a significant effect on the growth of silver pompano larvae. The results showed that the optimal dose of EPA and DHA oil was 300 ppm or 0.3 mL/L in treatment C with an average absolute length growth of 2.11 cm, and the survival rate reached 75%.

Influence of Water Temperature, Background Color, and Light Intensity in Feeding, Growth and Blind-Side Hypermelanosis of Starry Flounder, Platichthys stellatus (강도다리, Platichthys stellatus의 먹이섭식, 성장 및 무안측 체색발현에 있어 수온, 수조색상 및 조도의 영향)

  • Kang, Duk-Young;Kim, Won-Jin;Kim, Hyo-Chan;Chang, Young Jin
    • Korean Journal of Ichthyology
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    • v.26 no.3
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    • pp.185-193
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    • 2014
  • To find the influence of water temperature, tank color and illumination in feeding, growth and blind-side hypermelanosis of starry flounder, Platichthys stellatus, in the present study, we performed a series of temperature, background color and illumination intensity test for 180 days (From June to December). The test was done in duplicate at 100 fish/tank (430% of initial covering area [PCA]) with the selected ordinary juvenile flounder (TL $17.3{\pm}0.5cm$, BW $82.5{\pm}0.2g$). The rearing was performed in darkgreen FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 1,000 lux and 230 lux, and in white FRP aquarium tank ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 230 lux of light intensity. We investigated correlation of daily food intake (DFI) with water temperature and salinity, and compared the influences of background colors and light intensity in DFI, food efficiency (FE), growth, survival rate, and ratio of malpigmented blind-side area and ambicolored fish ratio. In DFI, although it was not related with salinity, the amount was significantly decreased under 0.5 g/fish/day in summer and winter season, but was significantly increased over 1.5 g/fish/day in autumn season showing from $10^{\circ}C$ to $20^{\circ}C$ in water temperature. In background and illumination test, DFI, FE and survival rate showed no difference among three groups. The ratios of malpigmented blind-side area and ambicolored fish were also not significantly different among three groups, indicating that the blind-side hypermelanosis of starry may be governed not by background color (or light intensity) but by a genetics external trait inherited from parents.