• Korean journal of food and cookery science
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• v.32 no.5
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• pp.656-663
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• 2016

Purpose: This study was aimed to compare the nutritional content of the life stages of Tenebrio molitor. Methods: Nutritional element analysis comprised 12 minerals, 18 amino acids, 4 vitamins, and 12 fatty acids in larval, pupal, and adult stages. Nutritional element content was expressed as a percentage of 100 g of sample and determined in raw and freeze-dried samples to assess the food value of the insect. Results: Moisture, crude protein, and crude fat contents in raw samples were 63.5%, 23.19%, and 3.96%, respectively. Moisture content was significantly higher in the adult stage than in larval and pupal stages, whereas crude fat and crude ash contents were lower. Mineral composition of the mealworm showed K, P, and Mg in decreasing order of content, with no differences among life stages. Total amino acid content increased from adult, pupal to larval stages, in order with each stage's growth, without difference in amino acid composition. Seventy-six to 78% of total fatty acid corresponded to unsaturated fatty acids, with oleic acid as the most abundant. In addition, fatty acid content was high in the adult stage, and clear differences were observed between life stages. Finally, vitamins B1 and B3 showed similar content between life stages, whereas vitamin B2 showed a higher content the adult than larval and pupal stages. A higher folate content was observed in pupal and adult stages than in the larval stage. Although freeze-dried samples showed a higher nutritional content than raw samples, both samples were similar in composition and content between life stages, suggesting the suitability of freeze-dried samples for use as food materials. Conclusion: These results may provide a basis for more diversified industrial applications of the Tenebrio molitor.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.4
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• pp.251-259
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• 2009

Swimming crabs, Portunus trituberculatus(Miers) are commercially important off the coasts of Korea, Japan and China. Harvest of swimming crabs has been fluctuated along their distribution ranges. Fluctuations in the interannual harvest of swimming crabs may be correlated with the survival rate during the larval period. The survival rates, intermolt periods, and growth of larval swimming crabs were investigated in the laboratory. Larval swimming crabs are released and undergo development from April to August off the western coast of Korea in the Yellow Sea. Sea surface temperatures off the western coast of Korea during the larval season were used for the laboratory experiments, and ranged from 22 to 26${^{\circ}C}$. Larvae were individually cultured at four different temperatures, 22${^{\circ}C}$, 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Zoea molted to megalopa at all temperatures and developed to the first crab stage at 24${^{\circ}C}$, 26${^{\circ}C}$, and 28${^{\circ}C}$. Survival rates from zoea I to the first crab stage increased with increasing temperatures. Intermolt period and the growth rate of the mean carapace length were inversely correlated with temperature. Our research helps understand the changes in survival rate and growth of larval swimming crabs resulting from changing oceanic temperatures. Further, our study suggests that the fluctuations in fishery harvest of swimming crabs off the coast of Korea may be related to changes in larval survival affected by changing ocean conditions.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.265-268
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• 2004

Larva of Carassius auratus and Pungtungia herzi were exposed to mercury ($HgCl_2$), lead ($PbCl_2$) and copper ($CuSO_4$) to determine acute toxicity. The toxicity tests were conducted triplicate and the $LC_{50}$ values (24, 48, 72 and 96 hours) were determined for two species. Data obtained from the toxicity tests were evaluated using the probit analysis. Although sensitivities of two species to mercury were relatively similar, C. auratus was more susceptible than P. herzi to the exposure of lead but P. herzi was more sensitive than C. auratus on copper. The sensitivity on three metals tested may be ranked in the following order from highest to lowest toxicity on larval stage of these fish: mercury > copper > lead. It is suggested that acute toxic test at the larval stage of C. auratus and P. herzi, indigenous species in Asia area, is an important part of the ecotoxicological assessment of some heavy metals.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.630-633
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• 2000

The damage by the black-tipped sawfly, Acantholyda posticalis posticalis, has been increasing all over the area of Korean pine(Pinus koraiensis)stands in Korean peninsula. This study was conducted to provide basic information for the management and control of this pest by investigating the feeding quantity of pine needles during the larval stage. The results were summarized as follows : The total needles damaged in the larval stage of the black-tipped sawfly were 9,584mm in length on an average and those of female and male were 11,774mm and 7,394mm, respectively. The total length ingested actually was 7,797mm and it was equivalent to 81.4% of the total length damaged. Early larval stage showed a little feeding and it was equivalent to 17% of total quantity. On the contrary, the feeding quantity in late larval stages of fourth and fifth instars amounted to 83%. The number of the frass excreted per larva was about 1,160, and the difference between male and female was not showed, whereas it showed remarkable difference among larval instars.

• Journal of fish pathology
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• v.21 no.3
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• pp.167-174
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• 2008

Few studies on parasitic scutica-like ciliates (SLCs) influencing larval growth and survival during the seed production of the Japanese scallop, Patinopecten yessoensis have been performed in spite of relatively high magnitude of their infectious damage to the larvae. In the mass seed production of the scallop, SLCs were never infectious during D-larval stage which lasted 6 to 7 days. Indeed, the infection first occurred in 2 to 4 days after first umbo-staged larvae. A regular selection of active larvae in swimming behavior kept larval SLC infection low throughout the culture compared to unselected control (P<0.05) in which all the larvae alive were contained. Higher infection frequencies of the unselected control resulted in lower larval survivals and wider range of larval size distribution that drove larval attachment rate lower. To the worse, the nursery spats from the higher SLC infection exhibited a retarded growth and elevated occurrence of abnormal scallop.

• Parasites, Hosts and Diseases
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• v.47 no.1
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• pp.65-68
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• 2009

Excretory-secretory products of Toxocara canis larvae have been considered as a major functional antigen in immune responses against toxocariasis. We studied ultrastructural localization of T. canis second-stage larval antigen using a seropositive human serum under immunogold electron microscopy. High-density gold particles were observed in the secretory cells, excretory duct, intestinal epithelium, and cuticle of the larval worm sections. The distribution of the positive reactions in the larval worms suggests that the nature of the antigen is excretory-secretory antigen including waste metabolites and secretory enzymes.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.799-804
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• 1998

laboratory experiments were conducted to determine the effects of Dimilin, an insect growth regulator which acts to inhibit chitin synthesis, during the larval development of liocarcinus corrugatus Pennant. The larvae was exposed to control (10 ppb acetone sea water and untreated sea water solution) and five concentrations 0.1, 1.0, 5.0, 10.0 and 25.0 ppb of both TG and WP-25 formulations of Dimilin from the hatching to the megalopal stage, and the effect of Dimilin on development of the larvae were determined. Two formulations (TG and WP-25) had different effect on the different stages in L. corrugatus. and early stage larvae of L. corrugatus were more sensitive to TG than to WP-25. Concentrations of diflubenzuron >5.0 ppb are lethal to L. corrugatus larvae upon chronic exposure. Lethal concentrations are defined here as those in which less than 10% of the larvae survived to the megalopal stage. However, Dimilin (TG and WP-25) showed no significant effects on developmental time of L. corrugatus larvae.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.144-152
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• 1998

Changes of biological components in haemolymph of Helicoverpa assulta Guenee were investigated during the development and pupae of cold-stress periods. Protein content was the highest in the larval stage, whereas it showed somewhat lower level at the cold-stressed pupae. The level of free amino acids was high in the larval and adult stages. Althougth decresed in pupal stage, the level of free amino acid remarkably increased at the cold-stressed pupae. Total lipids were a little increased at the pupal stage, after small quantity decreased in I-day old adults, and then remarkably decreased at the cold-stressed pupae. Glycogen was increased at the pupal stage, and somewhat decreased in the stage of adult, but remarkably decreased at the cold-stressed pupae. From thin layer chromatographic analysis, glucose was detected in small quantity at 1-day old pupae, one-day old adults, and cold-stressed pupae, respectively. Each .activity of acid and alkaline phosphatases was the highest in the 1 and 7-day old pupae, respectively, and both enzyme activities were increased about two-fold compared to the activity in the cold-stressed pupae. A total of 2 phosphatase isozymes were observed in throughout the developmental stage, and a new isozyme specific to cold-stressed pupae was identified.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.9-18
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• 1995

The study made an observation on periodicity of oviposition, and the effects of nutrient and salinity in egg un larval development of Aedes togoi, and the results are summarized as follows: The 53.9% mosquitoes of one feeding laid eggs once, 26.9% laid hice and 19.2% laid three times. Autogenous rate of Aedes togoi reared in three different nutrient groups in larval stage was 6.9% in 0.8 mg/larva, 22.5% in 1.6 mg/larva and 44.4% in 2.4 mg/larva. The oviposition rate according to different salinity of the oviposition sites (0%, 0.5%, 1.0%, 2.0% and 4.0%) was 25.2% in distilled water, 36.2% in 0.5% salinity 23.5% in 1.0% salinity and 14.6% in 2.0% salinity. Developing period of the aquatic stage of male Aedes toBoi in $25^{\circ}C$ were shorter (10.73 days) than females (11.85 days). The most effective concentration of salinity for the developing period was 1.0% which took 9.25 days in males and 10.44 days in females. In the developmental status of the follicles according to nutrition in the larval stage, the numbers of follicles of groups fed 0.8 mg, 1.6 mg and 2.4 mg per larva were 180.7, 197.% and 202 respectively. The result of ovary dissection on the 1 with day after emergence, three different nutrition groups were in Christopher's stage IIa mostly; each 71.0%, 61.1% and 39.9% of the total follicles and autogenous females observed.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.103-103
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• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.