• Development and Reproduction
• /
• v.22 no.1
• /
• pp.39-53
• /
• 2018

The purpose of this study is to investigate the early life history of the Rhodeus fish, Rhodeus uyekii and R. ocellatus, in the Nakdong River to use as the preliminary data for the systematic study. The embryos used in the study were fertilized eggs (embryo) and larvae after artificial fertilization. The long diameter of the eggs of the R. uyekii was 3.39-3.97 mm (average $3.68{\pm}0.41mm$, n=30) and the short diameter was 1.36-1.55 mm (average $1.45{\pm}0.13mm$, n=30). The long diameter of the eggs of the R. ocellatus was 2.53-2.71 mm (average $2.62{\pm}0.12mm$, n=30) and the short diameter was 1.47-1.60 mm (average $1.53{\pm}0.09mm$, n=30). Hatching time was 48 hours for the R. uyekii and 50 hours for the R. ocellatus given that the average water temperature was $21.5^{\circ}C$. The hatched larvae were 4.95-5.00 mm (average $4.98{\pm}0.04mm$, n=5) for the R. uyekii and the total length was 3.66-3.69 mm (average $3.67{\pm}0.02mm$, n=5) for the R. ocellatus. R. uyekii was found to be 15.5-15.8 mm at total length (average $15.6{\pm}0.21mm$, n=5) on the 56 days after hatching with the number of dorsal fins being ⅲ-9, anal fins ⅲ-10, ventral fins ⅲ-5. The R. ocellatus was found to be 15.8-16.0 mm (average $15.9{\pm}0.14mm$, n=5) at total length on the 58 days with the number of dorsal fins being ⅲ-11, anal fins ⅲ-12 and ventral fins ⅲ-5 where the number of all fin stalks reached maximum.

• The Korean Journal of Pesticide Science
• /
• v.18 no.1
• /
• pp.14-20
• /
• 2014

This study is aimed to search the possibility of developmental toxicity test using the zebrafish from the pesticide. We selected herbicides alachlor and butachlor, reported for fish toxicity, and insecticide fipronil reported for the high fish toxicity and the honey bee risk among the pesticides with high usability for the examples of the pesticides in this experiment. In this study, we showed those effects on the zebrafish embryo development by exposing different kinds of pesticide with different concentration and exposed time periods. As a result, the rates of hatching and abnormality of the zebrafish embryo after treatments of alachlor were increased in 24-48 hpf group, and the juvenile fishes in every group exposed to $40{\mu}M$ or more of alachlor displayed sever morphological changes such as bent tails, edema and activity failures. In case of the butachlor, the rates of hatching and the abnormality in 24-48 hpf group were higher than the other groups exposed in different time periods. The fatality before hatching was high in $40{\mu}M$ or more of butachlor treatment, and entire zebrafish embryos in 48 hpf group died before hatching. All the living juvenile fishes showed morphological changes as like as the treatment of alachlor. The rate of hatching and the survival of the zebrafish embryo by the fipronil were higher than other pesticides. However, morphological changes such as bent tails were observed from the most of living juvenile fishes. Therefore, the effects of three different pesticides with different concentrations and exposing time periods on the development of zebrafish embryos showed that all the pesticides effects were proportional to the concentration, and exposing time periods may cause the morphological abnormality.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.4
• /
• pp.307-313
• /
• 1997

Seed germination test done in laboratory does not coincide with field emergence in general. The experiments were carried out to examine the effect of priming and $GA_3$, treatment to seeds of Platycodon grandiflorum; Codonopsis lanceolata and C. pilosula on lapsed time to first seedling emergence, seedling emergence, morphological characters and growth and the cause of poor emergence of C. pilosula. No-treatment as Control (water), priming or $GA_3$ treatment was done with only distilled water for 2 days, $CA(NO_3)_2$ 150 mM for 2 days or $GA_3$ 0.1 mM for 3 days, respectively. Seedling emergence rate was counted every 2 days but morphological characters and dry weight of shoot and root were measured on 38 days after sowing. Their internal seed structures were examined with Scanning Electron Microscope. C. pilosula had poorer seedling emergence rate than P grandiflorum and C. lanceolata showing nearly same rate: Compared to the other treatment (s) P. grandiflorum displayed higher rate in priming and $GA_3$, treatments but C. lanceolata or C. pilosula did the greatest rate in only $GA_3$ or priming treatment, respectively. $GA_3$ treatment to seeds of P. grandiflorum and C. lanceolata shortened the lapsed time to seedling emergence in comparison with Control, 2-days water imbibition before sowing. In all the species plant height and number of leaves per seedling became shorter and less in priming treatment than the other treatments except plant height of C. Pilosula while their hypocotyl length was nearly same in all treatments. Although priming treatment had nearly similar effect to morphological characters, $GA_3$ treatment forced greater shoot, root and aftermath total dry weight per seedling. Poor seedling emergence of C. pilosula was caused by its seed defect like cleavage or lack of embryo, poor development of embryo and endosperm or their separation.

• Korean Journal of Ecology and Environment
• /
• v.44 no.1
• /
• pp.1-8
• /
• 2011

We investigated developmental stages of embryo and early life history of the Korean indigenous fish, the northern loach, Cobitis pacifica in 2009 in order to understand fundamental knowledges for conservation of this species. Eggs were obtained after hormones injections (LHRH-a, HCG) and were artificially fertilized by the dry method. The embryo was spherical, separative demersal, faint white, and averaged $1.09{\pm}0.04\;mm$ (n=20) in diameter. The hatching of the embryo took place in about 48 hours after fertilization under water temperature of $21.0{\sim}24.0^{\circ}C$ and the newly hatched larvae averaged $2.87{\pm}0.05\;mm$ (n=20) in total length (TL). Four days after hatching, the larvae grew up to $6.86{\pm}0.10\;mm$ (n=10) in TL and york sac absorption, mouth and anus opening were shown. Fourteen days after hatching, most of fin-rays appeared at $10.71{\pm}0.34\;mm$ (n=10) in TL and color spots on the body surface were attained. Twenty six days after hatching, the larvae grew up to $14.88{\pm}0.45\;mm$ (n=10) in TL, and all their fin-rays were formed. Therefore, according to current study regarding the morphological development of Cobitis pacidica, the conversion from larval to juvenile stages occurred at 26 days after hatching. Eighty days after hatching, the larvae were $33.3{\pm}1.25\;mm$ (n=10), and their body shape and color pattern were similar to adult fish. In this study, embryonic development and early life history of the northern loach, Cobitis pacifica show morphological characteristics of Cobitidae family. We expected that our results can be used as an fundamental knowledges for restoration study of indigenous fish species.

• Korean Journal of Ecology and Environment
• /
• v.47 no.2
• /
• pp.82-90
• /
• 2014

To assess the adverse effects of suspended solids on fishes, the hatching rate of embryo, and survival and growth of larvae were measured with common fish species of river such as crusian carp (Carassius auratus), common carp (Cyprinus carpio) and medaka (Oryzias latipes). Bioassay on hatching rate of embryo was conducted with a range of turbidity as 10 levels from 0.2 to 8,080 NTU. Another bioassay on 4-day larval survival and 21-day larval growth were also conducted with a range of turbidity as 8 levels from 0.1 to 8,260 NTU, and 6 levels from 0.7 to 2,030 NTU, respectively. The hatching rate of C. auratus was not significantly different from that of control at turbidity below 4,040 NTU, whereas it decreased when turbidity was 8,080 NTU (p<0.05). The hatching rate of C. carpio was not affected by concentration of suspended solids. For O. latipes, the hatching rate significantly decreased from 254 NTU (p<0.001) and it was zero when turbidity was 8,080 NTU. The 4-day survival of larvae of all 3 species was not affected by turbidity, while the larval growth of all 3 species was significantly affected. The turbidity effect on the growth of C. auratus and C. carpio was observed from 7 days after the exposure at turbidity level of 145, 143 NTU, respectively. The turbidity effect on the growth of O. latipes was observed from 14 days after the exposure at turbidity level of 254 NTU. The results of this study will provide the basic information for the derivation of water quality criteria on suspended solids for the protection of aquatic ecosystem and the quantitative ecological risk assessment of freshwater environment.

• Development and Reproduction
• /
• v.20 no.2
• /
• pp.109-118
• /
• 2016

This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of $1.35{\pm}0.04mm$ and an oil globule diameter of $0.32{\pm}0.02mm$. The fertilized eggs hatched 67-75 h after fertilization in water at $20{\pm}0.5^{\circ}C$. The total length (TL) of the hatched larvae was $3.62{\pm}0.16mm$. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was $4.72{\pm}0.07mm$. At 40 DAH, the juveniles had grown to $30.44{\pm}4.07mm$ in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3-4 vertical stripes appeared. At 45 DAH, the juveniles were $38.67{\pm}5.65mm$ in TL and $10.10{\pm}0.94mm$ in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.

• Journal of Embryo Transfer
• /
• v.28 no.4
• /
• pp.325-335
• /
• 2013

The study was set for one year to measure the effects of concentrate supplementation on reproductive performances and semen quality in indigenous rams. The study was conducted at the Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from May 2011 to April 2012. Forteen ram lambs (4~5 months) were randomly divided into two equal groups (n=7); supplemented vs control. The animals of control group were maintained on natural grazing. Along with natural grazing the supplemented group was on supplemented feeding. The concentrate supplementation (Wheat bran, Crushed maize, Soy bean meal, Fish meal, DCP powder, Vitamin mineral premix, Salt) was provided @ 300 g/head /day to the supplemented group. Body weight, scrotal circumference, BCS and libido index were measured weekly. Age, body weight and scrotal circumference at puberty were recorded. Semen was collected once in a weak using artificial vagina and chilled at $5^{\circ}C$ for 48h for evaluation. Concentrate supplementation did not influence (p>0.05) body condition score, age, weight, scrotal circumference at puberty and libido index. Final body weight (kg), growth rate (g/d), scrotal circumference (cm) and scrotal growth rate (mm/15d) were significantly (p<0.05) higher in supplemented group of rams compared to control. Volume, concentration, motility and membrane potentiality of spermatozoa were varied significantly (p<0.05) in supplemented and control groups. However, density, mass motility, viability and sperm with normal acrosome, midpiece and tail were not differed insignificantly (p>0.05) in different observation times. It was concluded that concentrate supplementation with free grazing improved weight and scrotal circumference gain and semen production with increased quality in indigenous ram.

• Journal of Life Science
• /
• v.20 no.11
• /
• pp.1634-1639
• /
• 2010

This study was conducted to increase the efficiency of farming practice in rainbow trout, Oncorhynchus mykiss, by sex reversal and chromosome-set manipulation techniques. To obtain phenotypic males, hormonal sex reversal was carried out using an exogenous hormone treatment method. 5 mg of 17 alpha-methyltestosterone per kg diet was supplied for 82 days after first feeding at $10^{\circ}C$ and $13^{\circ}C$. More than 93% of the male population was produced by this method and growth of hormone-treated fish at $13^{\circ}C$ was faster than that of untreated bi-sexual groups. Induced diploid gynogenesis was carried out using artificial insemination of UV-irradiated sperm into haploid eggs. Based on the appearance of the rate of haploid syndrome and survival of embryo, a UV ray dose of at least $3,600\;erg/cm^2$ was required to inactivate rainbow trout sperm genetically. Haploid embryos were restored to diploid by blocking the extrusion of the second polar body using heat shock treatment at $28^{\circ}C$ for 20 min, 10 min post insemination. Gynogenetic diploid sex ratios were confirmed after maturation of the fish erythrocyte measurements and chromosome counts.

• Journal of Genetic Medicine
• /
• v.7 no.2
• /
• pp.156-159
• /
• 2010

Inversion, one of the balanced rearrangements, usually does not lead to phenotypic abnormalities; all genetic information exists in the proper amount, merely in a different order or in an abnormal location. However, offspring of an inversion carrier is at risk of chromosomal imbalance because an inversion loop can be formed during crossing-over of the paternal and the maternal chromosomes in meiosis. We report a 38-year-old woman with inversion and balanced translocation and her fetus with unusual rearrangement causing chromosomal imbalance. We performed conventional cytogenetic analysis, MLPA, and subtelomeric FISH in the cells of the embryo. The results showed that the distal portion of chromosome 13q was added to the terminal portion of chromosome 9p during crossing-over. Therefore, the final karyotype of the fetus was 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat, confirmed using molecular-cytogenetic analyzing tools.

• Development and Reproduction
• /
• v.17 no.4
• /
• pp.329-335
• /
• 2013

TCR subunits are members of membrane-bound receptors which allow the fast and efficient elimination of the specific fish pathogens have regulated function in adaptive immunity. Sequence structure of TCR subunits have been reported for various teleosts, but the information of each TCR subunit functional characterization through expression analysis in fish was unknown. In this study, we examined the gene expression of TCR subunits in the early developmental stages and observed transcript levels in various tissues from healthy adult olive flounder by RT-PCR. The mRNA expression of alpha subunit was already detected in the previous hatching step. But the transcripts of another TCR subunit were not observed during embryo development and increased after hatching and maintained until metamorphosis at the same level. It was found that all TCR subunits mRNAs are commonly expressed in the immune-related organ such as spleen, kidney and gill, also weak expressed in fin and eye. TCR alpha and beta subunit were expressed in brain, whereas gamma and delta were not expressed same tissue. The sequence alignment analysis shows that there are more than 80% sequence homology between TCR subunits. Because it has a high similarity of amino acid sequence to expect similar in function, but expression analysis show that will have may functional diversity due to different time and place of expression.