• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.267-273
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• 1977

Rainbow trout were reared in a small indoor aquarium which was equipped with a simple recirculating biofilter combined with a small amount of inflowing water for 199 days from April 25 to November 10, 1977 in Busan where very hot summer air temperature is encountered, and results obtained were promissing as following; 1. The aquarium has dimensions of $1m\;\times\;1m\;\times\;67cm(depth)$, and a bottom center sedimentation chamber of conical type through which out-flowing water is pushing fecal matter and other detritus outward. The conical sedimentation chamber measures 20 cm depth and 20 cm diameter at its upper mouth and tapers to the bottom end which is connected to 4 cm diameter draining pipe. The draining pipe goes through under the tank and then is elevated on the side. The water depth was maintained at about 40 cm depth by adjusting the heigh of draining pipe. The filter bed contained 16 l of $3\~5\;mm$ zeolite gravels, and water circulation rate was about 1030 l/hr. 2. Continuous inflowing water resulted in a good elimination of waste materials through its outflowing water thus reducing waste loading in the filter. 3. Mean temperature of water in the rearing aquarium containing about 400 l water volume was maintained at around 20 to $22^{\circ}C$ by 0.59 l/min of the inflowing well water which usually maintained the temperature of $17^{\circ}C$ during the hot summer season from the first of July to the first of October when the 10-days-mean air temperature ranged from $20^{\circ}\;to\;27.3^{\circ}C$ $(total\;mean\;24.6^{\circ}C) $ and under this condition the fish continued normal growth. 4. The production per 1 l/min of inflowing water with this simple biofilteration reached 30 hg. 5. The total cost including all feed and power during this experimental rearing period fell well within the economic establishment and if the feed and filteration system are improved the benefit-cost ratio will be much increased.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.77-82
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• 1997

This study was carried out to investigate the developmental characteristics and life cycle of sciarid fly (Lycoriella sp.), an important mushroom pest. The sciarid fly was reared ina growth chamber at 21$\pm$$1^{\circ}C$ and 55$\pm$5% of relative humidity with a 16h high, 8h dark cycle and Flammulina velutipes was used at diet. The egg was oval with 0.17 mm in diameter and 0.27 mm in length. Average egg period was 4 days. Body length of each instar from the 1st to 3rd was 0.7, 1.5, and 4.5, mm. respectively. Average weight of each instar was 1.9, 15.4 and 93.6 $\mu\textrm{g}$, respectively. In the 4th instar larvae, however, developmental characteristics of female and male became different by body length, weight and segment size. Body length and weight of the 4th instar female larvae were 5 mm and 162$\mu\textrm{g}$, and those of the male larvae were 3.5 mm and 90 $\mu\textrm{g}$, respectively. The larval periods of female and male were respectively 13.5 and13 days. Pupal length of female and male was 3.5 and 2.7 mm, and average weight was 136 $\mu\textrm{g}$ and 6.5$\mu\textrm{g}$, respectively. Adults were emerged from female and male pupae on 5.5 and on 5 days after pupation, respectively. Average longevity of male and female were 7 and 5 days, respectively. The weight of female was two-fold heavier than the male. After copulation, female laid approximately 130 to 150 eggs on/in the sporophore of mushroom. In conclusion, total lifespan of male and female were 29 and 28 days, respectively.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.67-72
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• 1997

To study the ecological characteristics of the mulberry longicorn beetle, Apriona germari Hope, Mulberry branches with egg-laid scar were regionally collected from ten mulberry fields during the hibernation. It showed that its distribution was highest in Kyunggi province with 3.05% and lowest in Kyungnam province with 0.28%. The number of the egg-laid scar per branch was single with 87.7% of high frequency and its average size was 2.38 L$\times$1.45 W$\times$0.34D cm. The average diameter of scarred branch was 1.7 cm, ranging from 1.3 to 1.9 cm. the shape of egg was long elliptical with width of $2.32\pm$0.33 mm and with length of $6.606.60\pm$0.55 mm. the weight of egg was $16.6\pm$2.94 mg and the color of the just-oviposited egg was milky white, changing into thick brown with time. The weight and length of the just-hatched larva was $16.6\pm$2.4 mg and $6.36\pm$0.66 mm. respectively. Most of the larvae moved downward inside the branch, showing that 94.2% of larvae for outdoor rearing and 87.9% of larvae for indoor rearing moved downward in the branch. As a result, it was found that it hibernated at egg stage with a higher rate than at larval stage by two or three folds in Kyunggi and Kyungbuk province and contrarily at larval stage with higher rate than at egg stage in Chunbuk, Chunnam and Kyungnam provinces. The survival rate for the egg after hibernation was significantly low with 6.6% and contrarily for the larva after hibernation remarkably high with 91.2%. Although the survival rate of the egg in this survey was relatively low, the result indicated that there were two types of hibernation of A. germari in Korea; egg and larval stage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.2
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• pp.115-124
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• 1977

From August 1976 to May 1977, a series of rearing experiments of eels weighing over 5 grams were carried out utilizing indoor recirculating aquariums and the results are summarized as following: 1. The eels were instantly acclimatized in the aquarium when alive Tubifex was fed as food, resulting in the food coefficient of around 5, and the daily growth rate of $2\%$ or so (Table 2). 2. When mackerel flesh was used in combination with flour dough or commercial powdered feed, the food coefficients were 4 to 5 and daily growth rates were between 1 and $2\%$ (Tables 3 and 4). 3. The eels of 12.4-14.7g in average weight which had not shown any growth when fed processed feed, grew normally when they were fed alternately with alive Tubifex and processed feed with the results of 4.3-6.0 in food coefficient and $1.4-2.3\%$ in daily growth rate (Table 5). 4. Experimental processed feed containing North Pacific which fish meal as the main ingredient showed the food coefficient of 1.31-1. 83 as dry material and this means that there is not any significant difference between this experimental feed and the control commercial eel feed, imported front Japan which showed food coefficient of 1.34 and 1.328 (Tables 6 and 7). 5. The feed cost may be reduced by about $45\%$ (based on tile domestic prices in the spring 1977) if this experimental processed feed is used instead of imported commercial feed. 6. Uneven growth is markedly significant in eels, and those which showed retarded growth gave very poor food efficiency as well as poor growth rate until they reach the size of about 30 grams. Thereafter they recovered both the normal food coefficient and growth rate. 7. Individuals which have been showing significant retarded growth may have some inherent physiological factors but this poor growth might also be, more or less, results of some external factors which are considered necessary to be investigated.

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.61-65
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• 2005

Egg-forming and preservation methods for the indoor-rearing system of the emma field cricket, Teleogryllus emma, were investigated. The oviposition preference experiment on different mats, soil(natural oviposition mat) and $oasis^{\circledR}$(artificial oviposition mat), showed that T. emma preferred to oviposit on the $oasis^{\circledR}$. On the other hand, $oasis^{\circledR}$ had more inactive number of eggs laid per female and hatchability than another. However, the number of eggs laid per female and hatchability within 50 days after emergence were better than soil. The experiment on the hatching of the eggs showed that eggs could be stocked at $10^{\circ}C$ for 40 days with 14 day pre-period after laying, representing $62.1\%$ hatchability, when considering generation shortening. On the other hand, When it had been kept in cold storage for 90 days at $7.5^{\circ}C$ with 14 day pre-period after laying it, appeared to be the most suitable for long period-storage method by hatchability $65.1\%$.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.105-112
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• 2009

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) and the sweet potato whitefly, Bemisia tabaci (Gennadius) are serious insect pests that have a wide host range including cucumber, tomato, and pepper. In this study, we tested larvicidal efficacy of several on-the-market environment-friendly agricultural materials (EFAM) to select the effective products after the target pests were stabilized in indoor rearing condition. The developmental periods of two whiteflies are as follows: in the case of T. vaporariorum, egg duration is 9.6 days and nymph is 18.9 days, and in the case of B. tabaci, egg duration is 7.4 days and nymph is 15.2 days under $25^{\circ}C$ with relative humidity (RH) of $60{\pm}5%$ and a photoperiod of 16 L:8D. The total period of T. vaporariorum was 5 days longer than B. tabaci. Among 22 EFAMs six products showed more than 60% of insecticide efficacy against T. vaporariorum BTV B, BTV D, BTV G, BTV L, BTV M, and BTV S. On the other hand, seven EFAM products showed over 60% of insecticide efficacy against B. tabaci BTV D, BTV G, BTV K, BTV L, BTV M, BTV N, and BTV U. In the case of Spodptera litura previously, 16 EFAMs were tested against $2^{nd}$ instar S. litura, and six EFAMs were found to have more than 90% efficacy. Test of these six EFAMs against entire larval stages were performed in this study. Although some of these products showed still more than 90% of insecticidal efficacy against up to $3^{rd}$ instar larvae, the efficacy of these EFAMs sharply decreased as ages increase, resulting in less than 60% of efficacy of the products at most. This result indicates the difficulty to control S. litura with the on-the-market EFAMs alone under economic injury level. Collectively, it is required to find more EFAMs, and find alternative method, and combined way of controlling to control those insect pests tested in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1319-1327
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• 2014

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of $15^{\circ}C$ and $19^{\circ}C$. Fish averaging $92.2{\pm}0.7$ g (mean${\pm}$standard deviation [SD]) at $15.0{\pm}0.5^{\circ}C$ and $100.2{\pm}0.4g$ ($mean{\pm}SD$) at $19.0{\pm}0.5^{\circ}C$ water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at $15^{\circ}C$ and 1.5% BW/d at $19^{\circ}C$. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at $15^{\circ}C$ and fish fed groups of 1 meal every 2 days at $19^{\circ}C$ were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at $15^{\circ}C$ than $19^{\circ}C$ water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at $15^{\circ}C$ and 100 g to 132 g at $19^{\circ}C$ water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.197-205
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• 1984

From 1981 to 1982, a series of experiments on the optimum growth temperature, wintering temperature and lethal minimum temperature of the walking catfish Clarias batrachus, of about 12 to 40 g yearlings, were carried out using indoor recirculating aquariums at water temperature between $14^{\circ}C\;and\;34^{\circ}C$. The results are as follows. The optimum temperature of this species was turned out to be approximately $25^{\circ}C$ with highest feed intake and growth rates, and lowest conversion rate than at any other temperatures. The minimum temperature at which the fish can show growth turned out to be $18^{\circ}C$, At this temperature daily growth rate for 62 days was about $0.1\%$ and all fish survived. When this species was kept at $16^{\circ}C$ or lower, no fish survived more than one month and at lower than $14^{\circ}C$ all fish died out in 1 to 7 days. In accordance with these results it could be inferred that $18^{\circ}C$ is the minimum wintering temperature. Rearing this species at the minimum growth temperature for a long time, for wintering for instance, the sudden change of water temperature, especially decreasing to lower than $15^{\circ}C$ can be lethal for all fish.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.19-24
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• 2003

Artificial spawning, larval and spat developments of the bay scallop, Argopecten irradians, which was transplanted from China on 16 August 1996, were investigated monthly until August 1997 in the Deukyang Bay, Jangheung-gun, Jeollanam-do, Korea. Sufficient amount of cultured microalgae supplemented seawater were supplied as food (6 kinds of phytoplankton) for fully grown adult individuals at 17.1-23.2$^{\circ}C$ for 44 days. A total of 45,320,000 eggs were spawned by way of 2 times of artificial spawning inductions such as exposure stimulus to the air and thermal shock (with water temperature) on 29 January and 31 January in 1997. Artificially fertilized eggs were developed to D-shaped larvae (77.5 ${\times}\;63.8\;{\mu}m)$ and metamorphosed to larvae (191.8 ${\times}\;181.2\;{\mu}m)$ 181.2 m) in the attached larval stage on the collectors. A total of 110,000 spats (average 3.04 mm in shell length) were produced at 22.8-26.3$^{\circ}C$ and 31.0-34.4 psu in the indoor rearing tank from 14 February through 7 May in 1997. In case of Argopecten irradians, if the attached larvae in the attachment stage are detached from the collector, they could not live. Accordingly, it is assumed that survival (%) of the attached larvae of A. irridians showed very low because of weak power attached to the collector due to the small number of the byssuses of the attached larva, not the short attachment period by the byssus as seen in other scallops such as Argopecten balloti.

• 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.