• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.394-399
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• 2011

The effect of intermittent feeding on growth, feed utilization and body composition of subadult olive flounder fed extruded pellet (EP) in suboptimal temperature ($13.5{\pm}2.10^{\circ}C$) was determined. Two hundred twenty five subadult fish averaging 272 g were randomly distributed into fifteen of 300 L circular flow-through tanks (fifteen fish per tank). Five treatments with different days of feeding a week were prepared in triplicate: fish were hand-fed with EP to apparent satiation once a day, seven days a week (7DF), which was used as the control group or consecutive six, five, four and three days a week, for 12 weeks, referred to as 6DF, 5DF, 4DF and 3DF treatments, respectively. Weight gains and specific growth rates of fish in 6DF treatment were higher than those of fish in 7DF, 4DF and 3DF treatments, but not different from those of fish in 5DF treatment. Daily feed intake of fish in 6DF and 7DF treatments was higher than that of fish in 5DF, 4DF and 3DF treatments. Feed efficiency and protein efficiency ratio of fish were not different among treatments. There was no difference in the chemical composition of fish between treatments. Results of this study demonstrated that feeding five days per week could be recommended for subadult olive flounder fed extruded pellet in suboptimal temperature.

• Fisheries and Aquatic Sciences
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• v.26 no.7
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• pp.455-459
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• 2023

40 species of the family Caprellidae Leach, 1814 are recorded in Korean waters. Caprella aino Utinomi, 1943 was newly collected from seaweed farms from the southeastern waters of Korea. C. aino was firstly reported in Japanese waters in 1943. Adults of C. aino and Caprella mutica Schurin, 1935 are easily distinguished in that C. aino have pereonite II and gnathopod II without setae and two small tubercles of articulation of gills in pereonite III-IV, while C. mutica do pereonite II and gnathopod II covered with setae and those of pereonites III-VII with many tubercles. However, subadult C. mutica is hardly distinguishable from C. aino in that tubercles of pereonite III are less developed and they have inconspicuous setae of pereonite II and gnathopod II. Nevertheless, C. aino is distinguished from subadult C. mutica because adult C. aino have dorsal tubercles on pereonite IV, V, VI, VII unlike that of C. mutica. We report C. aino as a new record in Korean water with comparison of C. mutica.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.322-328
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• 2015

Three feeding trials were conducted to investigate the optimal feeding rates of subadult Korean rockfish Sebastes schlegeli at low, optimal and high water temperatures. In Exp-I, triplicate groups of fish (248 g) were fed a commercial diet (CD) with five different feeding rates of 0.1%, 0.2%, 0.4%, 0.6% and 0.8% body weight per day for 10 weeks at the low temperature ($11.6-15.2^{\circ}C$). In Exp-II, fish (129 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 10 weeks at the optimal temperature ($16.0-18.8^{\circ}C$). In Exp-III, fish (85.7 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 12 weeks at the high temperature ($21.0-28.5^{\circ}C$). The optimal feeding rates in the low, optimal, and high water temperatures were estimated to be 0.56%, 0.93% and 1.17% body weight per day, respectively, for subadult Korean rockfish.

• Fisheries and Aquatic Sciences
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• v.27 no.8
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• pp.525-532
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• 2024

The strategy of cultivating healthy fish by manipulating their gut microbiota composition using probiotics is crucial for establishing sustainable fish farms. Information on the gut microbiota composition of healthy fish is important for the efficient development of probiotics and the aquaculture strategies that would apply them. This study assessed the gut microbiota composition of farmed olive flounder according to the growth stage to provide useful information for the development of probiotics. The fish were classified according to their weight, and the intestines of five juveniles weighing less than 100 g and five subadults weighing between 400 and 800 g were used for analysis. The results of alpha diversity analysis confirmed higher richness and diversity in the subadult group than in the juvenile group. Beta diversity analysis revealed clear boundaries and distances between the groups; however, individuals within each group were similar. The two groups showed marked differences in their gut microbiota composition. Phylum-level analysis revealed that the most abundant phylum was Proteobacteria in the juvenile group and Firmicutes in the subadult group. Notably, genus-level analysis revealed that Vibrio accounted for more than 50% of the total composition in the juvenile group. Linear discriminant analysis effect size revealed that the genera Vibrio, Photobacterium, and Leuconostoc were representative of the juvenile group, whereas 19 genera, including Lactococcus and Vagococcus, were representative of the subadult group. Thus, information on the representative microorganisms abundantly present in the intestines of healthy olive flounder can be considered for the selection and development of a probiotic genus for olive flounder farming.

• Animal cells and systems
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• v.7 no.2
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• pp.93-103
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• 2003

Two diastylid species, Dimorphostylis manazuruensis Gamo(1960) and Dimorphostylis longicauda Gamo(1962), are recorded as new to Korea cumacean fauna. The subadult male of D. longicauda is described for the first time. As a result, the genus Dimorphostylis found in Korean waters now consists of eight species.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.815-819
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• 1994

Sixty eight wild rats, Rattus norvegicus, were caught from Seoul city, Kyonggi, Kangwon, Cholla, and Kyongsang-provinces. All sera collected from rats were examined by immunofluorescent test to find antibody against murine typhus. The antibody prevalance to murine typhus was 4.4%(3/68). Sero-positive rate was 12.5%(2/16) in Kyonggi province and 12.5%(1/8) in Cholla province. The sero-positive rate difference between sexes of rats was not recognized. Three Rattus norvegicus having antibody to murine typhus were morphologically classified as subadult with 8.3%(1/12), middle-aged adult with 5.9%(1/17), and old adult with 4.8%(1/21), respectively.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.321-326
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• 1993

Sixty eight wild rats were caught from Seoul, Kyonggi, Kangwon, Cholla, and Kyongsang provinces in Korea. All of them were confirmed in the same species, Rattus norvigicus. All of sera from wild rats were examined by indirect immunofluorescent test against Hantaan-related virus. Detection of anti-body to Hantaan-related virus were 4 out of 68 rats(5.9%), including 2 of 8(25.0%) rats in Kangwon and 2 of 20 rats(10.0%) in Kyongsang province. No difference of the sero-positive rates between sex of rats tested to Hantaan-related virus was recognized. According to age, four rats with antibodies(1:320~640) to Hantaan-related virus belonged one subadult, one young adult, one middle aged adult, and one old adult, respectively.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.505-513
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• 1995

Seventy wild rats were caught from Seoul city, Kyonggi, Kangwon, Honam, and yongnam provinces. All of them were in same species, Rattus norvegicus, except two R rattus from Kyonggi province. Seventy sera from wild rats were studied by immunofluorescent antibody assay for evidence of infection by spotted fever group rickettsia. The antidody prevalance was 37.14%(26/70) for spotted fever group rickettsia. The sero-prevalence rates for spotted fever group rickettsia antibody was the hightest in Kyonggi province with 55.56%(10/18), yongnam province with 50.00%(10/20), Kangwon province with 25.00%(2/8), Seoul city with 18.75%(3/16), and Honam province with 12.50%(1/8). The sero-positive rates difference between sexes were higher in female with 46.15%(12/26) than in male with 31.81%(14/44) for spotted fever group rickettsia. Twenty six of 68 Rattus norvegicus with antibody for spotted fever group rickettsia were in subadult with 50.00%(6/12), young adult with 38.89%(7/18), middle-aged adult with 35.29%(6/17), and old adult with 33.33%(7/21). No antibody was detected from R rattus.

• Journal of Forest and Environmental Science
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• v.38 no.1
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• pp.55-63
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• 2022

The African swine fever virus (ASFV) remains contagious for a long time, not only in the carcass, but also in the bone marrow of an infected animal. The scavenging activity of various animals on ASFV-infected carcasses is a likely risk factor for ASFV transmission. Thus, we conducted this study to determine whether scavengers are potential vectors for ASFV. In nonprotected wild boar carcasses on the forest floor, we investigated the seasonal patterns of carcass decomposition and scavenger visits for feeding on them. The duration from fresh to early skeletonization (only bones and leather remaining) of adult carcasses was 37.6±23.1 days (n=3, range=11-51 days) in winter. The duration from fresh to later skeletonization (only bones and some fur remaining) of all carcasses, including subadult carcasses, was 8.3±2.5 days (n=4, range=7-12 days) in summer. At all three study sites, leopard cats (30.3%), large-billed crows (21.6%), and golden eagles (18.1%) were the frequently visiting species, representing more than 10% of the total visits (343 visits) in winter, whereas raccoons (21.9%), grey-backed thrushes (39.4%), and eyebrowed thrushes (14.7%) were the most frequent visitors in summer. In winter, crows or cinereous vultures were the first animals to arrive at a carcass; in summer, raccoons or crows arrived first. Our results showed that wild boars, raccoons, and leopard cats relatively frequently visited wild boar carcasses and stayed there for a long time. Wild rodents chewing on or staying near carcasses were photographed during winter. In addition to wild boars, thus, mammals, such as raccoons, leopard cats and rodents, and birds, such as accipitrids and thrushes, may be spreaders of ASFV in South Korea.

• Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.380-392
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• 2023

Groupers (Family Epinephelidae) are commonly caught in data-poor small-scale multi-species fisheries for sale on both export and domestic markets. This study presents data on the species composition and size/life-stage structure of Epinephelus spp. groupers caught by small-scale fishers and sold locally in the Indonesian province of South Sulawesi. Data were collected from fishing ports and local markets at 12 sites representing the three seaways around South Sulawesi (Makassar Strait, Flores Sea, Gulf of Bone). Each specimen (n = 3,398) was photographed alongside an object of known length, and total length (TL) was obtained using the Rapid Scaling on Object (RASIO). Of the 23 species identified, four (Epinephelus areolatus, Epinephelus ongus, Epinephelus quoyanus, and Epinephelus fasciatus) collectively comprised 69% of the catch, while the 13 least abundant species contributed less than 5%. The catch was dominated (67%) by the subadult life-stage, with just under 20% in the adult class. Juveniles dominated the catch of Epinephelus fuscoguttatus, a valuable export commodity. Observations of early maturity as well as the sizeable gap between length at first capture (Lc) and length at first maturity (Lm) indicate recruitment overfishing of most species, with the notable exception of Epinephelus rivulatus. The proportion of adult fish was low (≈5%-30%) for the twelve most abundant species (E. areolatus, E. ongus, Epinephelus quoyanus, E. fasciatus, Epinephelus coioides, Epinephelus faveatus, Epinephelus sexfasciatus, Epinephelus maculatus, Epinephelus bleekeri, Epinephelus corallicola, E. fuscoguttatus, Epinephelus polyphekadion). For two moderately abundant species (E. faveatus and E. malabaricus), TL < Lm for all specimens. The limited data available indicate spawning ratio is lower than reported from deep-water fisheries of E. areolatus and E. coioides. The results call for targeted research to fill knowledge gaps regarding the biology and ecology of groupers exploited mainly for domestic markets; highlight the need for species-level data to inform management policies such as minimum legal size regulations; and can contribute towards species-level status assessments.