• Parasites, Hosts and Diseases
• /
• v.36 no.2
• /
• pp.81-90
• /
• 1998

The present study was performed to observe the infection status of several kind of animals with indigenous Gnnthostomn in Korea, and morphological characteristics of gnathostome larvae detected from pit-viper, Askistronon breuiccudus, for the species bullfrogs. several kinds of snakes, j.e., 55 Elnphe rufodorsata, 2 Dinodon rufozonatum rufzonatum. 62 Rhnbdophis tisrinus tigrinus and 87 Askistronon app., and 438 cats were examined. A total of 21 larval gnathostomes was detected from 12 pit-vipers, A. breuicnudus. They were 2.233 x 0.343 mm in average size and covered with about 210 transverse rows of minute cuticular spines. Their characteristic head bulbs were provided with 4 rows of hooklets of which average numbers in each row were 36.8, 39.0, 41.7 and 44.3. posteriorly. In the cross sections of midgut level, the intestinal wall consisted of a single layer of 19-25 elongate epithelial cells with a single nucleus. SEM observation of the larvae revealed unique features of head bulb , cuticular spines on transverse striations and a cervical papilla. On the basis of above morphological characteristics, they were identified as the advanced third-stage larvae of Gnothostomo hispinum. It was first confirmed that the pit-viper. ABkistronon breuicaunus is the snake intermediate host of G. hispidun.

• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.435-439
• /
• 1995

Some characteristics and pathogenicity of Hyphantria cunea nuclear polyhedrosis virus (HcNPV), a potential microbial pesticide was studied. H. cunea NPV replicated in the nucleus of S. frugiperda cells cultured in the TNMFH medium. In case of virus infected cell, prepolyhedra formation was observed at 24hrs post-infection. At 48 hrs post-infection, Most of the infected cell contained many mature polyhedra which were released into culture media 72 hrs post-infection, with the cells grown in suspension culture, pH of the culture medium increased during the virus replication: the pH of fresh medium was 6.35 and rose to 6.77 within 120 hrs. Polyhedra formed a band in linear density gradient of sucrose by centrifugation, which co-sedimented with $50{\sim}55%$ sucrose. The shape of the purified polyhedra was mostly tetragonal hexahedron and its size was about $2.5{\mu}m$. Electron microscopy and phase contrast microscopy showed that many bundled nucleocapsids were occluded in mature polyhedra at 48 hrs post infection. H. cunea larvae infected with NPV showed a higher motality in the second and third instar than in the fourth instar. Death rate of H. cunea larvae in the second and third instar fed with leaves coated with $1.5{\times}10^{9}{\sim}l.5{\times}10^{7}PIBs/ml$ reached more than 90%.

• Korean Journal of Ichthyology
• /
• v.36 no.2
• /
• pp.120-128
• /
• 2024

In this study, the characteristics of the early life history were investigated for the Hypomesus nipponensis in the west coast Daeho Bay. Egg's were adhesive eggs that had the property of sinking in water in a circular shape. The size of mature eggs was 0.52~0.66 (average of 0.59±0.03, n=30) mm. The hatching time took 140 hours at a water temperature of 22~23℃. Immediately after hatching, the yolk sac larvae was 4.78~5.60 (average of 5.25±0.26, n=30) mm in total length, and the mouth and anus were not completely opened. On the 7 days after hatching, the preflexion larvae was 5.91~6.64 (6.32±0.21) mm in total length, and the mouth and anus were opened, and feeding activities were started. On the 25 days after hatching, the flexion larvae was 9.70~12.3 (10.2±0.63) mm in total length, and the end of the spine at the tail end began to bend upward. On the 42 days after hatching, the postflexion larvae was 14.1~18.8 (16.9±1.44) mm in total length, and the end of the spine at the tail was completely bent at 45°. On the 56 days after hatching, it reached the integer with 10 dorsal fins, 16 anal fins, 7 ventral fins, and 19 caudal fins. According to the study, there were spot-shaped melanophore vesicles under the pectoral fins during the incubation period, the different positions of the egg yolk compared to the battlefield, the deposition of melanophore vesicles on the back and under the body of the caudal part during the postflexion larvae period, and the absence of melanophore vesicles on the torso between the head and the starting point of the dorsal fin. It was distinguished from related species in that melanophore vesicles were deposited in one row from the back of the body to the caudal part during the juvenile period.

• Journal of Environmental Science International
• /
• v.29 no.9
• /
• pp.935-938
• /
• 2020

This study investigated the oviposition characteristics of Protaetia brevitarsis seulensis after emergence as adults from the larva collected from three regions in Gangwon-do, Chungcheongnam-do, and Jeju-do. The laying egg method was identified with zone breeding, and the average and cumulative number of eggs laid were measured once a week for seven weeks. The average number of eggs laid peaked until 4 weeks, and subsequently decreased. The source areas with respect to average number and cumulative number of eggs laid were in the order of Jeju > Chungnam > Gangwon. In conclusion, this result suggests a method for continuously improving management and economic feasibility of insect farming by securing genetic diversity, and raising the most productive breeds to select individuals form regions associated with high numbers of laid eggs.

• The Korean Journal of Zoology
• /
• v.37 no.3
• /
• pp.331-342
• /
• 1994

The larval development of Parupilumnus trispinosus Sakai, 1965 completed in the laboratory consisted of four zoeal stages and one megalopal stage. Completion of the lanral development required at least 18 days at 20-25"C. The morphology of the lanrae of each stage is described in detail, and comparisons are made with larvae of other 11 species of the subfamily Pilumninae. Although, the zoeae of the subfamily Pilumninae show almost consistent characteristics of the mouthpart appendages, in the characteristics of the carapace spines and the abdominal lateral knobs they can be divided into five groups: (1) the genera Heteropanope and Heteropilumnus, (2) the genera Actumnus and Pilumnus, (3) Pilumnopeus makiona and P sewutifrons, (4) Porupilumnus trispinosus, and (5) Pilumnopeus eucratoides and. p indic${\alpha}$.

• Animal cells and systems
• /
• v.3 no.1
• /
• pp.47-52
• /
• 1999

Change of proteins was confirmed during low temperature acclimation of overwintering larva, and some biochemical characteristics of the induced antifreeze protein-1 (AFP-1) were investigated in Protaetia brevitarsis. As the freezing point depression by the action of induced AFPs, a considerable thermal hysteresis was observed in the haemolymph and in partially purified proteins. AFP-1 was purified from the cold acclimation larvae by ammonium sulfate precipitation ion exchange chromatography, gel permeation chromatography, and electroelution. The purified AFP-1 was determined to be a glycoprotein (approximately 320 kDa, pl 5.8) composed of a single type of subunit (80 kDa). The high contents of hydrophilic amino acids (Asp, Glu, Lys, Asn, Gln, Arg, Ser, Thr) were also confirmed, showing similarity with antifreeze proteins from other insects.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.2
• /
• pp.170-179
• /
• 2021

This study was conducted to identify taxonomic differences in the characteristics of Acheilognathus majusculus and A. yamatsutae during their initial life history via an interspecific hybridization experiment. Hatching time required 36 h for MY and 49 h for YM at 21.5℃, showing a significant difference of 13 h between the hybrids. The hatching rates of the cross-bred eggs were 30% for cross MY (A. majusculus♀×A. yamatsutae♂) and 40% for cross YM (A. yamatsutae♀×A. majusculus♂). The hatching larvae size was total length 3.13-3.43 mm in MY and total length 3.89-4.22 mm in YM, which was larger in YM. The hybridization test between A. yamatsutae and A. majusculus that live in the same water stream confirmed that no interspecific reproductive isolation occurred.

• Journal of Sericultural and Entomological Science
• /
• v.16 no.1
• /
• pp.93-100
• /
• 1974

It is reported that the useful larval characteristics and cocoon quality is damaged when the silkworm is fed on the insecticides contaminated mulberry leaf. The results obtained are as follow： 1) Mortality is growing when the silkworm is fed with the leaf treated with 1,000 folds insecticides and left for 25 days. 2) There are differences in the effects on the useful larval characteristics according to the insecticides, 3) Hernial larvae are brought about when the silkworm is fed with lebaycid stained leaf. 4) Malformed cocoon and abnormal silk is caused by the insecticide stained leaf feeding.

• Journal of fish pathology
• /
• v.19 no.2
• /
• pp.127-139
• /
• 2006

From 2002 to 2004, various vibrios were isolated from the olive flounder, Paralichthys olivaceus of culturing size with disease signs. During this survey, it was known that the high proportion of Vibrio ichthyoenteri was occupied among the isolated vibrios. Generally, V. ichthyoenteri is well known as the pathogen of bacterial enteritis of olive flounder larvae. The aim of the present study was the compare the characteristics of two groups of V. ichthyoenteri, culturing sized olive flounder, and larvae of olive flounder showing the intestinal necrosis. The research was focused on the physiology, biochemistry, genetics in the two bacterial groups. The physiological and biochemical characteristics of the tested strains were very similar. The intergenic spacer (IGS) region between the 16S and 23S rRNA genes of 21 isolated strains and 3 reference strains, V. ichthyoenteri, were investigated by PCR fragment length typing and DNA sequencing. After the isolated strains were identified as V. ichthyoenteri, not only phenotypic characteristics of the isolated and reference strains but also homology of 16S-23S IGS of all isolated strains and reference strains as 99.1~100%. The V. ichthyoenteri showed 4 specific 16S-23S patterns and contained no-tRNA, tRNAGlu(TTC) , tRNAIle(GAT) tRNAAla(TGC) type .

• Journal of Environmental Science International
• /
• v.29 no.7
• /
• pp.785-788
• /
• 2020

We investigated the oviposition characteristics of Protaetia brevitarsis seulensis, focusing on zone breeding throughout the year in terms of the development and utilization of insect resources. To select Protaetia brevitarsis seulensis individuals laying a large number of eggs, the number of eggs laid for each individual was measured for each individual after emergence as adults from larvae grown at room temperature in five farmhouses. The five study zone included Gongju (Tancheon), Gyeonggi (Himsen), Chungnam (Gyeryong), Taean (Wonbuk), and Siheung (Baekse). The average oviposition tendency during a 12-week period obtained from the five regions was somewhat different; however, there was no remarkable difference in overall tendency. The maximum oviposition in Protaetia brevitarsisseulensis in the five regions occurred between 6 and 7 weeks. Compared toother regions, the average cumulative number of eggs laid during the 12-week period was higher (40%-60%) in Gongju (Tancheon) and Gyeonggi (Himsen). These results indicate that in two regions, zone breeding is selected as a system for increasing the demand for insects.