• Fisheries and Aquatic Sciences
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• v.26 no.10
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• pp.583-592
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• 2023

Celebes rainbow (Marosantherina ladigesi) is one of Indonesia's exported ornamental fish commodities, but the exploitation of this fish only relies on wild catches. The rise of unlimited fishing, especially those using poison, has changed the aquatic environment, threatening sustainability and causing fish extinction. This study aimed to evaluate the effectiveness of several types of feed in improving the absolute growth rate (AGR), specific growth rate (SGR), survival rate (SR), feed conversion ratio (FCR), feed efficiency (FE), hematology, and immune response of Celebes rainbow. The fish used in this study were male ornamental Celebes rainbow (M. ladigesi) weighing 1.32 ± 0.21 g/ind, reared in 54 L-aquariums at a stocking density of 30 individuals/aquarium for six weeks. The fish were fed according to the test diet consisting of live Tubifex sp worms, dry Tubifex sp worms, Spirulina platensis, and crumble pellets. The parameters observed were AGR, SGR, SR, FCR, FE, hematology, intestinal histology, liver histology, and a challenge test with the pathogenic bacteria Aeromonas hydrophila. The results showed that fish-fed live Tubifex sp worms had better AGR, SGR, SR, FCR, FE, hematology, and disease resistance compared to all other treatments. These results indicate that live Tubifex sp worms are the best feed for rearing Celebes rainbow.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.561-567
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• 1987

The purpose of this study was to find out the removal capacity of harmful ammonia by different filter media in the submerged biological filters in a given space of chamber. Four materials, pile cloth, corrugated skylight roofing plate, embossed plastic plate, and gravel, were used as the experimental filter media. Each filter medium was placed in two aquariums, each aquarium measuring $90cm\times60cm\times60cm\;(depth)$. Under the normal operating condition, the average of mean ammonia removal rates during the first and second functioning periods by each filter material which occupied tile space in the filter chamber (aquarium) was as follows: 1. Pile cloth: $8.381\;g{\cdot}m^{-3}.\;day^{-1}$ 2. Corrugated skylight roofing plate: $7.834\;g{\cdot}m^{-3}.\;day^{-1}$ 3. Embossed plastic plate: $7.797\;g{\cdot}m^{-3}.\;day^{-1}$ 4. Gravel: $7.051\;g{\cdot}m^{-3}.\;day^{-1}$ Thus, there were no significant differences between the media, but at the time of practical application of these materials, some other factors such as investment cost, easiness for the removal of excess detritus accumulated in tile interstices of filter media, etc. should be fallen into consideration. When large units are required, in particular, removal of excess detritus from tile gravel bed is extremely difficult, and in case of pile cloth filters the installation work is much complicated and a problem in supporting the structure when drained also exists. In these respects, corrugated skylight roofing plate and embossed plastic plate seem to be more optimal, but again in practice the local situation for the availability and the price of the materials should be rechecked and the fitness of tile materials in the particular filter chambers under use or under consideration for construction must be taken into account.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.57-63
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• 2022

On April. 2016, the anadromous icy goby caught at Shinbong-cheon, Tongyeong shi, Gyeongsangnam-do transported to the laboratory of Korea Institute of Ocean Science and Technology (KIOST) and observed spawning behavior and egg development and larvae. In aquarium, males make the nest under stone and waiting female entering. Fertilized eggs attached under the stone in the nest. Male protected the fertilized eggs until hatching. The size of the club-shaped eggs were 3.2~3.4 mm in the major axis and 0.6~0.8 mm in minor axis (n=10). The eyed eggs were hatched after 168 hrs in a range of water temperatures (18.0~20.0℃). The total lengths of newly hatched larvae were 4.1~4.4 mm (n=5) and these larvae had 32~33 (12~13+20) myotomes and transparent oval yolk. Three days after hatching, the pre-larva (4.9 mm in total length) has opening mouth and rectum. Post-larva with 5.2 mm total length have melanophore on air bladder, rectum, base of membranous caudal fin and 9~10 melanophores ventral row on the tail.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.259-266
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• 2014

This study investigated the effects of water temperature and photoperiod on oxygen consumption (OC) in the giant grouper Epinephelus lanceolatus. OC rate in the giant grouper at 17, 22, 27 and $32^{\circ}C$ were $61.7{\pm}0.4$, $72.2{\pm}0.6$, $102.9{\pm}0.8$ and $141.7{\pm}1.0mg\;O_2/kg/h$, respectively, indicating a linear increase in OC with water temperature. Photoperiod was regulated in accordance with the light (06:00~18:00 h, L) and dark (18:00~06:00 h, D) phases of the diel cycle (12L/12D), with a water temperature of at 17, 22, 27 and $32^{\circ}C$. OC rates during the light and dark phases were $62.7{\pm}0.4$, $62.5{\pm}0.3mg\;O_2/kg/h$, respectively, at $17^{\circ}C$. No significant differences were observed between the light and dark phases (P>0.05). OC raters during the light and dark phases were $74.8{\pm}0.7$, $69.6{\pm}0.6mg\;O_2/kg/h$ at $22^{\circ}C$, $107{\pm}1.2$, $98.0{\pm}0.7mg\;O_2/kg/h$ at $27^{\circ}C$ and $147.6{\pm}1.1$, $135.8{\pm}0.8mg\;O_2/kg/h$ at $32^{\circ}C$, respectively, indicating that OC is higher during daylight than nighttime. Giant grouper is thought to be a diurnal fish species, because the level of oxygen consumption during light period was higher than that during dark period.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.63-76
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• 1992

This study was carried out to investigate the appearance time of the second polar body for producing Gynogenesis or Triploid which could be obtained by arresting the second polar body by cold shock, and then blastoderm was used to measure fertility that revealed the nature of oogenesis, the effects of water temperature on fertility, hatchability, abnormality, viability and growth rate, and the water temperature and the breeding methods to prevent early death of larvae in Korean loach(Misgurnus anguillicaudatus) ; the results obtained in this study were summarized as follows. The second polar body was observed ont he surface of plasma disc close to micropyle within 10~40 min after fertilization at 29$^{\circ}C$. Artificial inseminatin had to be done immediately after the egg spawning because the spermatozoa of loach their mobility within 2 minutes when they were exposed to water. The amount of time needed to reach at blastoderm stage was 12 hours if fertilized eggs were incubated at 16$^{\circ}C$, 8 hours at 19$^{\circ}C$, 6 hours at 21$^{\circ}C$, 5 hours at 23$^{\circ}C$, 4 hours at 26$^{\circ}C$ and 3 hours 30 min at 29$^{\circ}C$ showing the shorter time for development of eggs at higher temperature. Fertilization rates in water temperatures of 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$, and 26$^{\circ}C$ were higher than those of water temperatures, 16$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 19$^{\circ}C$, 21$^{\circ}C$, and 23$^{\circ}C$ showed higher hatching rates that those of 16$^{\circ}C$, 26$^{\circ}C$, and 29$^{\circ}C$, while abnormal rates in 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$ and 23$^{\circ}C$ were lower than that of 26$^{\circ}C$ and 29$^{\circ}C$. Water temperatures at 16$^{\circ}C$, 19$^{\circ}C$, 21$^{\circ}C$, 23$^{\circ}C$ and 26$^{\circ}C$ respectively, were more different than 29$^{\circ}C$ in survival rates. The embryos were hatched at 72 hours after fertilization in 16$^{\circ}C$ water temperature, 48 hours in 19$^{\circ}C$, 40 hours in 21$^{\circ}C$, 32 hours in 23$^{\circ}C$, 25 hours in 26$^{\circ}C$, and 16 hours in 29$^{\circ}C$. Within three days after hatched out, the larvage grew 3mm in total length, the yolk granules were entirely consumed and the head and the trunk became thicker. Within 45 days after hatched out, the larva grew 25mm at 29$^{\circ}C$, 21mm at 26$^{\circ}C$, 16mm at 23$^{\circ}C$, 15mm at 21$^{\circ}C$, 12mm at 16$^{\circ}C$ in a 30 litreglass aquarium.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.193-198
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• 2011

We examined the effect of an artificial change of water temperature on the survival rate of Korean Scallop, Patinopecten yessoensis. As for the change of water temperature, the aspects appearing on the eastern coast of Korea during spring and summer were artificially prepared in the rearing aquarium in the laboratory. The survival rate of Scallop, due to the stimulus of a low water temperature in spring, was an average of 51.6%. Medium-sized scallops averaged 4.4%, which is lower than that of small-sized ones (85.82%) and large-sized ones (55.0%). The survival rate of Scallop, due to the stimulus of water at a high temperature in summer, was an average of 43.3%. As for small-sized scallops, they averaged a 46.7% survival rate which is lower than that of medium-sized scallops (60.0%). In general, the survival rate was lower in summer than in spring. Such results show that the death of Scallop, has close relevance to the change of water temperature. The low survival rate of medium-sized ones. Alternatively, medium-sized scallops have to get through winter, even if they cannot grow enough compared with large-sized ones. This is because large-sized scallops have already been adapted to the change of water temperature by getting through winter twice.

• Development and Reproduction
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• v.21 no.3
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• pp.287-295
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• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.28-36
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• 1974

For the development of acoustic fishing method, we had been researched a fundamental study which concerned on the sound production and behaviour of crabs was conducted. For specimen crabs such as Portunus trituberculatus and Charybdis japonica were selected. Croaking noise were recorded by the Cassette-recorder (Sony model CF-1600) through the under water monitor microphone, and analyzed in frequencies by Octave band analyzer, Rion SA-55, and sound pressure level of source by sound level meter, SM-5844. The following are the results obtained from the present investigations : When sound production of crabs (Portunus trituberculatus( female ) : carapace width $12.6\~15$cm) were attracted to another crabs in the water of anechoic aquarium, efficacy of phonotaxis was $84\~100\%$ and velocity by phonotaxis was $6.5\~7.2cm/sec$. The time required for copulation ranged from 90 minute to 95 minutes by Charybdis japonica, at that time there was no sound production with their copulation.

• Korean Journal of Veterinary Research
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• v.9 no.1
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• pp.71-78
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• 1969

The present studies were undertaken to determine accurately whether Korean native fresh-water shrimps can serve as the second intermediate host of Clonorchis sinensis. The experimental results obtained were as follows; 1. Metacercaria of Clonorchis sinensis was not discovered in 36 Macrobranchium nipponensis (De Hann), 1992 Palaemon paucidens (De Hann) and Palaemon madestus Heller, and 860 Caridina leucastica Stimpson, collected in Kimhae district, which were digested in artificial gastric juice, using binocular dissecting microscope. 2. Cercariae of the Chinese liver fluke could not approach the body wall of young shrimps due to streaming caused by their motion. 3. Young Palaemon spp. of 247 were divided into two groups and placed in two different room aquariums, one is at high temperature, the other is normal. Then they were contacted with the cercariae. Only 11 degenerated metacercariae were found in 9 Palaemon spp. It was suggested that they had died immediately or within a few days after penetration. Furthermore the temperature did not affect the infective ratio. 4. At the field experimental aquarium, no metacercaria of Clonorchis sinensis was discovered tn 100 Palaemon spp. which had been brought into contact with 5000 Parafossarulus manchouricus two trials. 5. Specific changes in the cercariae mixed with the extract of shrimps meat were not observed through the dissecting microscope. 6. These results suggest that the Korean native shrimps cannot serve as the intermediate host of Clonorchis sinensis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.373-379
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• 2009

This study investigated oxygen consumption rate (OCR), $Q_{10}$ coefficient and ammonia excretion rate of the greenling, Hexagrammos otakii Jordan et Starks with the average body weight of 250 g in a semi-recirculated respiratory measuring system. The experiment was done under three different water temperatures (10, 15, $20^{\circ}C$) and five different ambient ammonia concentrations (0, 2.5, 5, 10, 20 mg/L). As the water temperature and ambient ammonia concentration increased the OCR has significantly increased (P<0.05). Given experimental conditions, the OCR of greenling were $50.8{\sim}159.4\;mg\;O_2\;kg^{-1}\;hr^{-1}$ and the relationship of water temperature (T) and ambient ammonia concentration (C) on the OCR were following: OCR = 41.3 - 1.87T - 7.38C + $0.463T^2$ + $0.66lC^2$ + 0.642TC - $0.011T^3$ - $0.010C^2$ - $0.031TC^2$ - $0.001T^2$C ($r^2$= 0.9226). $Q_{10}$ coefficients were $1.88{\sim}3.50$ for $10^{\circ}C$ to $15^{\circ}C$, $1.03{\sim}2.73$ for $15^{\circ}C$ to $20^{\circ}C$ and $1.40{\sim}1.90$ for $10^{\circ}C$ to $20^{\circ}C$, respectively. In general, the ammonia excretion rate tended to increase with increasing of the water temperature within normal ambient ammonia concentration. However, interestingly, it was observed that ammonia was absorbed rather than excreted above the ambient ammonia concentration of $2.5\;mg\;L^{-1}$, regardless of the water temperature. Thus, the largest ammonia absorption rate (AAR) was obserbed at the level of $98.4\;mg\;TAN\;kg^{-1}\;hr^{-1}$. The relationship ambient ammonia concentration (C) on AAR was following: Y = 1.61 + $10.9X^{0.7}$ ($r^2$ = 0.889).