• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.462-468
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• 2004

In order to evaluate adaptation to the environment in released fish, digestive organ and body composition were compared among 1-year old cultured (CUL), released (REL) and wild (WIL) Black Sea Bream, Acanthopagrus schlegeli. Hepatosomatic index (HSI) of the REL was significantly lower than those of the CUL and WIL fish, but intestine weight index (IWI) of REL was significantly higher than those of the CUL and WIL fish. There were no significant differences in stomach weight index (SWI) and condition facto. (CF) among those different fish groups. The number of pyloric caeca of the REL and WIL fish were 4, but the $30{\%}$ of CUL fish was 3 counts. The moisture content of whole body in the WIL fish was significantly higher than the CUL and REL fish, but significant lowest in the crude lipid of whole body. The content of moisture and crude protein of dorsal muscle were no significant differences among the CUL, REL and WIL fish, but crude lipid content of WIL fish was significantly lower than the CUL and REL fish. Moisture content of CUL fish in the liver was significantly lower than the REL and WIL fish, and crude lipid was significant lowest in the WIL fish. Amino acid content of dorsal muscle in the WIL fish was highest in the total amino acid, EAA and E/A ratio, and CUL fish was highest EAA and E/A ratio in liver. EPA content in dorsal muscle of WIL fish was lower than CUL and REL fish, and the REL fish was highest in DHA content of the fatty acid. EPA content in liver of WIL fish was lower than CUL and REL fish, and DHA content in REL and WIL fish was highest and lowest. Crude protein content of CUL and WIL fish in the scale was significantly higher than REL fish, but there were no significant differences in contents of crude lipid and ash. Ca and P of scale were formed most of mineral and content of P in CUL fish was significantly higher than those of REL and WIL fish. There were no significant differences in Mg, K, Na and S of scale, but CUL fish was significantly lower than REL fish in C1. The results suggest that difference of digestive organs and body composition concluded it from differences of inhabitation environment and feed formulations.

• Journal of Veterinary Clinics
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• v.19 no.1
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• pp.1-6
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• 2002

We evaluated the wholesomeness of fish feeds treated with high-dose radiation. This study examined the safety of fish fed treated with high-dose irradiation (5 kGy) and butylated hydroxyanisole (BHA, 200 ppm). 100 flounder (Paralichthys olivaceus) were grouped into 4 and then the fishes fed the following feeds for 28 days: (1)standard feed; (2)standard feed, treated with BHA; (3)standard feed, irradiated to 5 kGy; (4)standard feed, treated with BHA and irradiated to 5 kGy. Four groups each 10 mice were fed the fish feeds same as (1)-(4) for 14 days. There were no observable differences between fishs fed the irradiated feed and those fed the standard feed with respect to growth, feed consumption, haematology and organ histopathology Parameters. There were no deviations in feed consumtion, haematology and organ histopathology parameters in the experiment of mice. We concluded that there were no irradiation-related effects.

• Journal of Aquaculture
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• v.19 no.3
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• pp.178-182
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• 2006

We studied new observation method about take process of rotifer by marine fish larvae. Till now, we can not accurate observation and count of first rotifer feeding day and/or feeding numbers of rotifer by marine fish larvae. Because take rotifer is ingested and disappeared in the digestive system of fish larvae. However we suggest possible observation method for these problems. The trophi is mastication organ of rotifer, and has only one in each rotifer individual. The trophi is left in the mastication organ because sole indigestible organ of rotifer. Therefore we can accurate observation and count of first rotifer feeding day and/or feeding rotifer numbers of marine fish larvae by trophi observation method (RTCM; Rotifer Trophi Counting Method).

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.282-293
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• 2020

This study investigated a long-term variation trend of water quality, fish compositions, and ecological health conditions in the Gwanpyeong stream located in the nearby Daejeon metropolitan city to understand the impact of urban development projects on the aquatic ecosystem. The sampling was made in four surveys (2009, 2010, 2016, 2019) before and after urbanization. The urban development was conducted in 2008, resulting in the stream's ecological disturbance, and the stream restoration was conducted in 2012. Thus, stream monitoring was conducted to analyze the ecological trends before and after the restoration. The multi-metric models for Fish Assessment Index(FAI) and necropsy-based Health Assessment Index(HAI) were applied in the fish community and organ-level, respectively, to assess the ecological health of the stream. Minimum turbidity and chlorophyll-a(Chl-a) occurred in the mid-stream(St. 2), and this was probably due to rapid current velocity in the riffle zone. We collected 18 fish species, and the dominant species was Zacco platypus (40.6%). In 2016 immediately after the stream restoration, the relative proportions of sensitive species and insectivore species were the highest along with highest values in the species diversity and species richness index, resulting in the best condition in the ecological health, based on FAI model values. However, the ecological health, based on the FAI, became worse in the latest survey conducted in 2019. The analysis of the HAI model based on the organ-level approach showed skin erosion in the fish of upper stream, kidney defects in downstream, and the liver and gill defects observed in all sites, indicating that the anatomical health was also affected.

• Animal Bioscience
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• v.34 no.7
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• pp.1181-1192
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• 2021

Objective: The objective of the current study was to investigate the effects of dietary hatchery by-products (HBPs) as a replacement of fish meal (FM) on growth performance, relative organ weight, plasma measurements, immune organ index, meat quality, and tibia characteristics of broiler chickens. Methods: A total of 720 broiler chickens (3 d of age) were randomly allotted to 1 of 9 treatments with 8 replicates. Each replicate consisted of 5 male and 5 female birds. The basal diet was formulated to contain 5.0% commercial FM, whereas eight treatment diets were prepared by replacing 25%, 50%, 75%, or 100% of FM in the basal diet with infertile eggs (IFE) or a mixture of various HBPs (MIX); therefore, the inclusion levels of IFE or MIX in the experimental diets were 1.25%, 2.50%, 3.75%, or 5.00%. The diets and water were provided on an ad libitum basis for 32 d. Results: Increasing inclusion levels of IFE as a replacement of FM in diets had no effects on growth performance, plasma measurements, immune organ index, and tibia characteristics of broiler chickens. Increasing inclusion levels of IFE in diets increased (linear, p<0.05) meat lightness (L^*) but decreased (linear, p<0.05) meat redness (a^*). The breast meat pH at 1-h postmortem was increased (linear, p<0.05) by increasing inclusion levels of IFE in diets. Likewise, increasing inclusion levels of MIX in diets had no effects on growth performance, relative organ weight, plasma measurements, immune organ index, and tibia characteristics. However, increasing inclusion levels of MIX in diets increased (linear, p<0.05) 1-h postmortem pH but decreased (linear, p<0.05) 24-h postmortem pH of breast meat. Increasing inclusion levels of MIX in diets decreased (linear, p<0.05) thiobarbituric acid reactive substances values of breast meat. Conclusion: Both IFE and MIX are suitable alternatives to FM as protein ingredients in broiler diets.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.924-929
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• 2015

In this paper, we suggest a phase difference algorithm inspired by weakly electric fish. Weakly electric fish is a fish which generates electric field though its electric organ in the tail. The weakly electric fish search for prey and detect an object by using electrolocation. The weakly electric fish have Jamming Avoidance Response (JAR) to avoid jamming signal. One of pulse-type weakly electric fish Gymnotus carapo also have JAR to reduce the probability of coincidence of pulses. We analyze this response signal and design the phase difference algorithm. We expect that simple algorithm inspired by weakly electric fish can be used in many engineering fields.

• Journal of Yeungnam Medical Science
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• v.28 no.2
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• pp.105-115
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• 2011

Mercury is a toxic, persistent pollutant that bioaccumulates and biomagnifies through food webs. People are exposed to methyhnercruy mainly through their diet, especially through the consumption of freshwater and marine fish and of other animals that consume fish (e.g., marine mammals). All humans are exposed to low levels of mercury. Dietary patterns can increase exposure to a fish-eating population where the fish and seafood are contaminated with mercury. The primary toxicity targets of mercury and mercury compounds are the nervous system, kidneys, and cardiovascular system. It is generally accepted that developing organ systems are most sensitive to the toxic effects of mercury. The fetal-brain mercury levels appear to be significantly higher than the maternal-blood mercury levels, and the developing central nervous system of the fetus is currently regarded as the main system of concern as it demonstrates the greatest sensitivity. The subpopulation that may be at greater risk for mercury toxicity are those exposed to higher levels of methylmercury due to carnivorous fish, including sharks.

• Journal of Nutrition and Health
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• v.5 no.3
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• pp.127-133
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• 1972

This study was designed to observe the effect of ethanol extracts from fish flour on the nucleic acid metabolism in rats. Young rats, weighing 75-85g were used as the experimental animals and diet used were 8 kinds; diet supplemented with 10% fish flour, diets which were supplemented with the extracts and or remainders of fish flour after extracting by either 76% or 96% ethanol to the rice diet, respectively, and diet supplemented with 6% casein. After feeding corresponding diet for 40 days, RNA and DNA contents, and DNase activities in the liver, kidney and braid were determined. The results obtaioed from this study are summarized as follows: 1. The RNA contents of the ethanol-treatment groups are, in the liver and kidney, similar to, and in the brain, generally higher than, that of the control group. 2. The DNA contents of each organ show no difference between ethanol-treatment groups and control group, but in the liver, of ethanol extrat groups are lower than casein group. 3. the DNase activity of each organ in the ethanol-treatmeut groups, is generally lower than the control group. The above results indicate that ethanol extracts from fish flour have influence on the nucleic acid metabolism.

• Applied Microscopy
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• v.50
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• pp.18.1-18.7
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• 2020

The olfactory anatomy and histology of Lethenteron reissneri were researched using a stereo microscope, a light microscope, and a scanning electron microscope. As in other lampreys, it shows same characters as follows: i) a single olfactory organ, ii) a single tubular nostril, iii) a single olfactory chamber with gourd-like form, iv) a nasal valve, v) a nasopharyngeal pouch, vi) a sensory epithelium (SE) of continuous distribution, vii) a supporting cells with numerous long cilia, viii) an accessory olfactory organ. However, the description of a pseudostratified columnar layer in the SE and Non SE is a first record, not reported in sea lamprey Petromyzon marinus. In particular, both 19 to 20 lamellae in number and olfactory receptor neuron's quarter ciliary length of the knob diameter differ from those of P. marinus. From these results, it might be considered that the olfactory organ of L. reissneri shows well adaptive structure of a primitive fish to slow flowing water with gravel, pebbles, and sand and a hiding habit into sand bottom at daytime. The lamellar number and neuron's ciliary length may be a meaningful taxonomic character for the class Petromyzonida.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.197-204
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• 2001

Endocrine disruption in crucian carp (Carassius auratus) living in the branch of Han River were examined. Vitellogenin level in plasma was measured using ELISA system and aromatase mRNA level in brain was observed using RT-PCR technique. In all female fish, vitellogenin levels were in the range of 20∼40 $\mu\textrm{g}$/ml and aromatase mRNA expression could be detected on the agarose gel after RT-PCR. However, in case of males, vitellogenin level was elevated in only one fish, while vitellogenin was hardly detected in others. Aromatase was expressed in all males although the levels were relatively lower than the level in female fish. Testis-ova and any other histological changes of reproductive organ were not shown in both sexes.