• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.56-63
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• 1995

Ecological study of the Cynoglossus joyneri was conducted based on the specimens from the western coast of Korea from 1992 to 1994. Ecological characteristics of this species such as gonadal development, occurrence of larvae, stomach contents, and environmental conditions were investigated. Few larvae of Cynoglossus joyneri occurred in Kunsan coast. This coast is influenced by the freshwater input of the Mangyong and Kum River, especially during the summer. Therefore, the larvae of C. joyneri were considered to be spawned and grown during their early life stage in the high saline water in outer bay. Spawning occur from June to September, having the peak spawning period from July to August. Biological minimum size of matured fishes containing mature oocytes is about 143.5mm in total length, which requires about 20 months after hatching. The ranges of total length by age are as follows : 0-ring group(floating stage), 30~70mm ; 1-ring group, 49.0~133.0mm 2-ring group, 128.6~167.0mm ; 3-ring group, 169.0~202.0mm ; 4-ring group, 200.7~240.0mm. The major food items of young fish under 8cm were copepods and invertebrate larvae, and those of adult fishes were annelids(polychaets) in winter, and bivalves and shrimps in summer and autumn. Therefore, it can be assumed that the population of C. joyneri could be reduced due to the decrease of food organisms caused by the continuous reclamation activities in the inner bays of the west coast of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.115-123
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• 1996

For ecological study of Synechogobius hasta the environmental factors, length composition, stages of ovarian maturation, growth, and stomach contents of this species were examined. The samples were collected from the Kum River estuary from May, 1994 to June, 1995. The ovarian egg development of this species underwent 4 stages : the oogonium stage in October to November, growth stage in December to February of next year, maturity stage in February to April, and spawning stage in late April to middle May. The peak spawning period appeared in early to middle May. The fecundity varied from 8,600 to 49,000 showing a exponential increase by body size. The minimum size having matured eggs was 225 mm in total length (standard length 180 mm). The larvae smaller than 10 mm appeared in late May, and young fish of total length $13\~15mm$ entered into bottom life in the shallow waters. The young fish grew rapidly and reached about 141.7 mm in late October. The fish inhabited in the subtidal zone from December to May of next year when began to spawn. The largest specimen examined in this study was 531 mm of male, 472 mm of female. The major food items of young fishes were copepods and invertebrate larvae, and those of adult fishes were crabs, fish, shrimps, cephalopods, and polychaetes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.1
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• pp.63-76
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• 2003

Species composition and seasonal variations of shrimp caught in the adjacent waters Geomundo, Korea were studied using the monthly catch of beam trawl fishery from November 1998 to October 1999. During in the study period, a total of 700,765 shrimps consisting 36 species, 27 genus and 11 families were collected. The community was dominated by Palaemon gravieri, Parapenaeopsis tenellus, Solenocela melantho and Plesionika izumiae. The peak abundance of shrimp occurred in summer, and low abundance in winter and spring. Major species occurred in area A, B and C was P. gravieri, and P. tenellus, and P. izumiae and S. melantho, respectively. The number of individual and abundance showed in July, and low in November. It was noted that values of species diversity, dominance and evenness indices were high in adjacent water Geomundo and lower in adjacent water Chodo and Chodo-Sonjukdo. Analysis of dendrogram of the clustering showed that there were two distinct groups; Geomundo group and Chodo-Sonjukdo group.

• Journal of Science Education
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• v.36 no.1
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• pp.153-165
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• 2012

This study investigated the frequent mistakes and the causes of the alternative conceptions in the animal classification by using the questionnaire and interview with the middle school students (N=300). As results, some students have difficulties classifying suggested animals into vertebrates or invertebrates : snakes (31.7%), shrimps (28.3%), turtles (25.6%), frogs (24.7%), and starfish (10.7%) in order of precedence. These errors seemed to be caused by intuitive thinking over characteristics of physical motions and appearance of suggested animals, wrong inference from comparing to features of familiar animals and the lack of observation experience of the vertebrate backbone. Furthermore, the results showed that relatively many students made a mistake classifying subgroup members of vertebrates such as classifying salamanders into the class Reptilia (45.3%) and turtles into Amphibia (40.3%). It is likely that those errors are affected by ambiguousness of classification terminology (e.g. the term of Amphibia) and weak ability in relating the physiological and ecological feature to standard of classification feature. In addition, sociocultural factors could influence animal classification as 'bat in birds', 'whale in fish, and 'penguin in mammals'. The present study implied that teaching and learning animal classification may require an appropriate guide focused on activities to explore major characteristics used for the animal classification standard through providing more chances of animal observation rather than the cramming method of learning induced by technical memorizing.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.4
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• pp.248-262
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• 2005

The purpose of this study was to identify the state of demersal fish resource catch by small trawlers, which live in the southern waters off Goheung. We investigated the results of catch of sample fishing vessels, and performed fishing experiments using the actual fishing operation vessels from early November in 2002 till end of October in 2003. The daily amount of catch per vessel of the 35 small trawlers selected as sample vessels was the highest in summer seasons(June and July) as 70kg and the lowest in winter seasons(January and February) as 45kg and Octopus minor occupied as 17 to 30kg nearly 30% of the total catch. Additionally the catch of Octopus minor per vessel, per dragging hour ranges 3 to 6kg, which is the highest in March and June and the low in January to February, April to May and September. In the fishing experiments using small trawler, during the study period, a total of 75 fish species were collected. The number of individuals by species consisted 58.2% in Shrimps, 17.8% in Fish, 2.3% in Cephalopod. Of these, Parapenaeopsis tenella was the highest in 29.2%, Squilla oratoria and Crangon hakodatel was 14.6% respectively and Octopus minor was 0.2% of the total number of individuals. As far as the appearance number of individuals by month was concerned, February was the highest and then May, April and June followed in order, and October showed the lowest. Additionally the monthly catch per dragging was the lowest in December to January as 20kg and the highest in July as 160kg. Specially, Octopus minor was caught throughout the year regardless of season and the catch was the highest at the period from March to June. When looking into the body mean length of dominant fishes caught, we could observe the followings; Trachurus japonicus 8.9cm, Cynoglossus robustus 10.8cm, Muraenesox cinereus 15.3cm, Setipinna taty 10.3cm, Amblchaeturichfhys hexanema 9.3 cm and Collichthys niveatus 8.9cm, most of which were in their immaturity when they were caught.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.598-603
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• 2000

This study was conducted to enhance the storage stability and the wholesomeness of salted and fermented shrimp manufactured with different salt levels by high hydrostatic pressure sterilization. The effects of high hydrostatic pressure treatment on the putrefactive bacteria in the fermented shrimps were investigated and the sterilization kinetics was analyzed. The initial microbial counts of the fermented shrimp with 8%, 18% salt aged for 6 weeks at $20^{circ}C$ were $1.6{\times}10^3,\;1.4{\times}10^4$ CFU/g for bacteria grown on Vibrio selective media, $9.3{\times}10^3,\;1.7{\times}10^5$ CFU/g for bacteria grown on Staphylococcus selective media, respectively, and null for bacteria grown on Salmonella selective media. The degree of the sterilization increased with the magnitude of the pressure and the treatment time. The fermented shrimp pressurized at 6,500 atm for 10 min had no detectable bacteria grown on Vibrio and Staphylococcus selective media at $10^2$ CFU/g detecting limit. High hydrostatic pressure sterilization could be analyzed by first order reaction kinetics. The $D_P$ values of the bacteria grown on Vibrio selective media of the fermented shrimp at 18% salt were higher than those at 8% salt, while those of the bacteria grown on Staphylococcus selective media showed an inverse trend. The $z_p$ values of 8% salt fermented shrimp were higher than those of 18% salt for both bacteria grown on Vibrio selective media and Staphylococcus selective media. High hydrostatic pressure treatment could be applied for the sterilization of the fermented shrimp, and the optimum high pressure sterilization condition was 10 min treatment at 6,500 atm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.727-738
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• 1998

Seasonal species composition of fishery resources was determined using samples collected by a stow net from April 1995 through January 1996 at 9 stations off Youngkwang. Catch data obtained from a set net using strong tidal current could be used for a quantitative analysis of dominant species. Of the 98 species identified, assemblages were consisted of $52.0\%$ in fishes, $44.6\%$ in shrimps, $2.0\%$ in cephalopods, $1.4\%$ in crabs and <$0.1\%$ in gastropods. Thryssa kammalensis, Crangon hakodatei, Metapenaeus joynezi and Johnius grypotus predominated in abundance, consisting of $68\%$ in the number of individuals, The abundance and species composition fluctuated seasonally, and species could be distinguished by life history pattern with seasons. Seasonal variation in species composition was greater than the spatial variation in a sampling period, As the fine sediment was predominated in the study area, the species composition were significantly different from those of other coastal waters of West Sea, Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.1035-1040
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• 2015

4-Hexylresorcinol (4-HR) has been used for prevention of melanosis in shrimp. Recently, 4-HR in EU and other countries was authorized with maximum residue levels of 1~2 mg/kg but remains unauthorized in Korea. Therefore, the aim of this study was to investigate the effect of 4-HR on melanosis inhibition and residual levels in Korean shrimp according to various concentrations and soaking times. We previously reported that the HPLC-FLD method can be used for detection of 4-HR at maximum levels of 1~2 mg/kg in shrimp. Our results show that residual levels of 4-HR in peeled and unpeeled shrimps were in the range of 0.86 to 13.46 mg/kg and 0.02 to 2.33 mg/kg, respectively. In addition, 4-HR treatment at concentrations of 10 and 20 mg/L for 72 h were effective for inhibition of melanosis in peeled shrimp compared with unpeeled shrimp. These results provide basic data for the establishment of guidelines and regulation related to 4-HR.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.17-24
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• 2013

The feeding habits of Repomucenus lunatus were studied using 232 specimens collected from January to December 2006 in the coastal waters off Gori, Korea. The size of R. lunatus ranged from 4.7 to 14.0 cm in standard length (SL). R. lunatus was a bottom-feeding carnivore which consumed mainly amphipods and polychaetes. Its diet also included small quantities of shrimps, cumaceans, bivalvies, gastropods, crabs, copepods, euphausia, mysids, stomatopods, ostracods and sipunculides. Amphipods were eaten predominantly for the smallest size class. The proportions of polychaetes increased gradually with increasing fish size and large size class of R. lunatus mainly consumed polychaetes. The feeding strategy graphical method revealed that R. lunatus is a specialized feeder. The mean number and weight of preys per stomach of larger size classes were higher than those of smaller size classes. The mean weight of preys per stomach ontogenetically changed with size classes.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.132-137
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• 1997

Effective storage facilities are required to stabilize the price of agricultural and marine products to preserve their qualities due to the big fluctuation of shrimp price in Korea. It is easy to make the cave because of good conditions of the land configuration, soil and convenient transportation. The cave storage can save the cost about 40% in building site and equipment, and about 50% in maintenance comparing to existing low temperature storage facilities. The cave storage provide to improve the quality of their stored products with the low heat conductivity, the constant temperature and humidity year round. Therefore, more low temperature storage facilities are required because the items are expanded from potatoes, sweet potatoes, onions, garlics, apples and chestnuts to tangerines, grapes, cabbages, radishes, and wet ginsengs. The demands of the low temperature storage facilities can be substituted into the cave storage facilities. Thus, studies are conducted to observe the changes of the components of the pure and the seasoned salted shrimps with fermentation period during stored at room temperature in cave and to establish the storing at underground facilities to produce high quality salted fish to make profit.