• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.319-321
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• 2001

Supply of ntrition-balanced feed is very important for growth of fish, especially for growth of early period of fish. Therefore, most of commercial feeds for larval and juvenile fish are relatively expensive due to high level of the several nutrients to satisfy their requirements for growth. Overfeeding larval fish may increase fish production cost because of larvae feeds high price and deteriorate water quality, eventually reduce growth of fish. (omitted)

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.17-22
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• 2017

Cooked mature silkworms have received increasing attention as a new source of income for sericultural farms. Quality improvement of these worms as the end-product requires prevention of the following: inclusion of unfertilized silkworm eggs, mixing with impurities, producing undercooked or overcooked mature larvae, and mixing spewed silk substance. Preventing unfertilized eggs and impurities and reducing undercooked or overcooked mature larvae can be achieved by sericultural farms. However, the prevention of spewed silk substance requires the development of new techniques. This study developed new techniques for optimum cold storage temperature, soaking, and hydro-thermal treatment to minimize the spewing of mature larvae prior to steaming: when larvae mature after 7 days on the $5^{th}$ instar, they should be soaked in water at room temperature of $25^{\circ}C$ immediately upon collection and stored at $8^{\circ}C$ for less than 3 days. They should be soaked in boiling water for approximately 10 s immediately before steaming to kill the larvae and cooked with steam. This method allows for the production of high-quality mature larvae without spewed silk substance. These new techniques will considerably improve the production of well-cooked quality mature larvae by minimizing silk substance spewed out from the larvae.

• Journal of Life Science
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• v.27 no.10
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• pp.1185-1190
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• 2017

Insects are gaining recognition as an alternative source of protein. As a result, more and more domestic farms have begun mass rearing of edible insects. In order to produce high quality insects, studies on the development of safe and nutritious feed sources are needed. Given the cost of rearing insects, agricultural and industrial by-products are good sources for feed. The efficient utilization of these by-products can help in reducing the cost of production and preventing environmental pollution. In the current study, Citrus unshiu peel (CP), soybean curd cake (SCC), soybean oil meal (SOM), and brewers dried grain (BDG) were investigated for their effects on larval growth and development of Protaetia brevitarsis. Interestingly, the feed with 10% SCC increased larval weight by 3.5 times. For the larval period, the group of 10% SCC was significantly shorter than the control. Furthermore, minerals such as Zn, Ca, K, Mg, Na, and P were recorded to be high in 10% SCC. A total of 17 amino acids were present in 10% SCC, of which tyrosine and arginine were predominant. The heavy metal contents were very small amounts or not detected in any of the investigated groups. These findings provided a scientific basis for the utilization of soybean curd cake as a nutritional feed source to promote larval growth and produce quality insects.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.421-429
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• 2016

Tenebrio molitor larvae contain large amounts of proteins, lipids and other functional materials, enabling this insect to be used as an edible food source in animal feeds and for industrialization. Although many efforts have been made to set up mass rearing systems, few studies have been conducted to establish optimal rearing conditions for the production of high quality T. molitor larvae. Herein we investigated 1) the effects of additional diets on the survival and fecundity of the insect, 2) the relationship between oviposition period and the uniformity of larval size, 3) the effects of rearing density and temperature on insect development, and 4) the storage stability of eggs and pupae at low temperatures given possible temporary production discontinuation. The addition of carrot and zucchini to the traditional wheat bran diet significantly increased the survival and fecundity rate of adult T. molitor. Of the three different oviposition sampling periods (3, 7, and 14 days) used to investigate the uniformity of the hatched larvae in each treatment, the period of 3 and 7 days provided higher uniformity than the 14 days oviposition period. Larval development was faster at $30^{\circ}C$ than at 20, 25, and $35^{\circ}C$. Interestingly, oviposition rates were highest at $20^{\circ}C$ but showed much slower larval development and lower uniformity at $30^{\circ}C$. Regarding the effect of larval rearing densities (1, 10, 20, 30, 40, and 50 larvae per 90 mm diam. dish), larval weight was significantly reduced at higher rearing densities, but larval longevity and length were not influenced by rearing density. The 30 larvae/dish is suggested to be a reasonable density to be applied to mass production systems. When kept at $4^{\circ}C$, T. molitor eggs showed a significant reduction in hatching rate; however, when stored under the same conditions, pupae emergence rates remained high until 10 weeks, suggesting that storage at low temperatures is more suitable for the pupal stage than the egg stage. Our findings suggest that an increase in T. molitor adult survival and fecundity rates and a uniformity of hatched larval development can be achieved with the following recommendations: a combination diet (including wheat bran), a 7-day oviposition period; a larvae-rearing temperature of $30^{\circ}C$, a rearing density of 30 larvae/dish, and the storage of pupal stages at low temperatures in the case of rearing discontinuation. This study serves as a strong foundation for the successful mass production of high quality T. molitor larvae.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.33-40
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• 2003

To obtain the basic information on culture conditions for the larvae of Saxidomus purpuratus, experiments were conducted on the population from southern coast for (1) the success in fertilization and development from artificial fertilization among different months of a year, (2) the viability of sperms after exposure to seawater, (3) and the effects of temperature, salinity, and food organism on the survival and growth of larvae. Gametes obtained from dissection showed high rate of fertilization at all months. But the rate of development was higher only May-July. Developmental success seemed to be related with the quality of eggs at the time of fertilization. Developmental times for 2-cell, 4-cell, 8-cell, blastula, trochophore larva, and veliger larva at 20$^{\circ}C$ were 1.5, 2, 4, 18, 24, and 32 hr, respectively. Sperms could survive for more than 8 hr, however, actively swimming sperms could be found within 1 hr after exposure to seawater. It is recommended that sperms should be used for fertilization as soon as possible when they are exposed to seawater. At temperature of 35$^{\circ}C$, all the larvae died during 48 hr. Larval survival decreased when salinity was either lower than 20 psu or higher than 40 psu, and was 0% when salinity was 10 psu. Optimal range of temperature and salinity for rearing larvae of S. purpuratus were 20-25$^{\circ}C$ and 20-40 psu, respectively. Larvae grew from 111.5 to 235.3 ${\mu}$m during 21 days. Larvae fed mixed diets grew faster than unialgal diets. The fastest growth was observed when larvae were fed on the mixture of Isochrysis galbana and Nannochloris oculata.

• Journal of Aquaculture
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• v.11 no.4
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• pp.437-447
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• 1998

In mass production of larval rockfish, Sebastes schlegeli, high mortality had been observed frequently. This may be the consequence of the low nutritional quality of the live feeds used. This experiment was designed to find out a suitable diet for the mass production of rockfish larvae. Three kinds of live feeds were tested ; plutei of sea urchin (Hemicentrotus pulcherrimus), L-type rotifers (Brachionus plicatiilis) and Artemia naupii. The latter two were enriched with ${\omega}$-yeast, Spirulina platensis and Super Selco before feeding to rockfish larvae. The sea urchin plutei caused to poor survival and growth rates for larval rockfish, and therefore, they were not seemed as proper feed for rockfish larvae. Enrichments of rotifers and Artemia nauplii with ${\omega}$-yeast, Spirulina platensis, or Super Selco improved survival and growth rate. But, rotifers enriched with Super Selco resulted in better rockfish larvae survival than those enriched with ${\omega}$-yeast. A sudden increase of mortality occurred around 11 days after birth. In this critical period, a shift feed such as Artemia nauplii had been supplemented with rotifers. After this critical transition period, the moratality gradually decreased by feeding Artemia nauplii enriched with PUFA. Feeding of mixed feed with rotifers and Artemia nauplii resulted in better larval survival and growth than those of each live food alone.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.741-752
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• 2020

Herein, the in vitro protein digestibility of lyophilized Protaetia brevitarsis larvae flour with and without defatting using 70% ethanol was compared with beef loin. Proximate analysis showed that the defatted larvae contained the highest protein content (p < 0.05). The viable counts of total aerobic bacteria, Escherichia coli, and coliform bacteria decreased significantly after defatting the larval samples with 70% ethanol (p < 0.05). Measurement of α-amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed higher amounts of low molecular weight proteins in the larvae compared to beef loin (p < 0.05). After in vitro digestion, the degree of protein hydrolysis of the digesta was higher for both larvae samples compared to beef loin (p < 0.05). No change was observed in the in vitro larval protein digestibility after defatting. These results highlight the excellent protein digestibility of P. brevitarsis larvae with high protein content. Defatting insect flour with 70% ethanol could enhance microbial safety while maintaining excellent protein digestibility.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.26-31
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• 1978

The objective of the present study was to investigate the effect of nicotine-contaminated mulberry-leaf, which was grown in the vicinity of tobacco drying plant (TDP), on cocoon crop. Mulberry-leaf harvested from the field at Sericultural Experiment Station (SES), Suweon, Korea, was used as control, supposedly nicotine-free leaf. Leaf harvested from the field in the distances of 30-50m, 300-400m and 700-800m from TDP was fed during the whole larval stage of the silkworm at. SES. The effect of leaf in each treatment level on the quantitative characters of the silkworm was summarized as follows; 1. Larval duration from 4th instar on was significantly longer in the TDP-leaf treatments than for the control. 2. Duration of matured silkworm appearance became longer as the distance of the mulberry-field from TDP got shorter, because the larval duration and growth of the silkworm were not uniform in the TDP-leaf treatments. 3. Mortality rates during the late larval, cocoon spinning, and pupal stages were highest for the 30-50m leaf, especially mortality rates during the late larval and pupal stage were serious. 4. Pupation rate was lowest for the 30-50m leaf and those for the 300-400m and the 700-800m leaf were not significantly different from that of the control. 5. Nicotine damage to cocoon weight and cocoon shell weight was significant in each TDP-leaf level. Cocoon shell ratio was reduced at the same extent in each level, compared with the control. 6. The ratio among cocoon-classes was significantly different between treatments, compared with best-cocoon ratio of 87.1% for the control. Cocoons were not uniform for the 30-50m leaf, and those for the 300-400m and the 700-800m leaf were as almost uniform as those for the control. 7. Loss of fresh cocoon yield became greater as the distance of the mulberry-field from the TDP-got shorter. In conclusion, the critical distance of mulberry-field, which influences larval health, cocoon quality and yield, appeared to be 800m from the TDP. Such other factors as wind direction and topographic location may be involved in the critical distance. 8. From the present experiment, we could obtain only the effect of nicotine on the silkworm through digestive system, since the silkworm was raised at SES in Suweon. If the silkworm.. were raised in the vicinity of the TDP, poison effect of nicotine on the silkworm could beo expected through exoskeleton and tracheal system as well as through digestive system.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.175-182
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• 2002

A new high yielding mulberry genotype, Victory-1 (V-1) was recommended to the field for irrigated areas by Central Sericultural Research and Training Institute (CSRTI), Mysore during 1996-1997. As K-2 and S-36 mulberry genotypes are already in the field, a study on the comparative performance of V-1, 5-36 and K-2 varieties, in terms of leaf yield, yield attributes, leaf moisture and moisture retaining capacity and their impact on silkworm rearing was carried out under Telangana conditions of Andhra Pradesh during 1999-2001. Among the three genotypes the leaf yield was found to be significantly (P < 0.01) higher in V-1 (64,130 kg/ha/yr) followed by S-36 (44,064 kg/ha/yr) and K-2 (23,990 kg/ha/yr). The maximum leaf moisture was also observed in V-1 (71.84%) compared to S-36 (66.86%) and K-2 (64%). The moisture retaining ability was more in V-1 (70.17%) followed by S-36 (66.20%) and K-2 (60.08%). The yield attributes were found to be significantly (P < 0.01) enhanced in V-1 over S-36 and K-2. Silkworm rearing results (bioassay) indicated a significant (P < 0.01) reduction in larval duration and improvement in larval weight, effective rate of rearing by number and weight, single cocoon and shell weights and shell ratio in the silkworm lots fed on V-1 variety followed by S-36 and K-2. Hence, in this study, V-1 was found to be superior among the three varieties studied.

• Journal of Aquaculture
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• v.19 no.1
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• pp.52-56
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• 2006

This study was conducted to investigate the effects of three different concentrations (6%, 8% and 10% final volume) of dimethyl sulfoxide (DMSO) on cryopreserved sperm of grass carp (Ctenopharyngodon idellus). Grass carp sperm was suspended in Kurokura extender #2 and equilibrated at $4^{\circ}C$ for 10 min. French straws (0.25 ml) of sperm were frozen from $4^{\circ}C\;to\;-4^{\circ}C$ at a rate of $4^{\circ}C\;min^{-1}$ and then ken $-4^{\circ}C\;to\;-80^{\circ}C$ at a rate of $11^{\circ}C\;min^{-1}$. The straws were kept at $-80^{\circ}C$ for 10 min and finally stored in liquid nitrogen $(-196^{\circ}C)$. The cryopreserved sperm was thawed in a water bath at $40^{\circ}C$ for 30 sec and fertilization, hatching rate and larval malformation were compared with fresh sperm (control). The fertilization rate of post-thawed sperm was comparable (from 88.21% to 94.30%) to that of fresh sperm. However, hatching rate of all frozen sperm were significantly lower (P<0.05) than that of control. Additionally, the larval abnormality rate of frozen sperm was significantly higher than that of fresh sperm. The results indicate that DMSO could affect the quality of cryopreserved sperm of grass carp, and a freezing program and a proper extender composition should be further studied.