• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.110-115
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• 2016

This study was conducted in order to investigate the growth and morphological development of Cypselurus hiraii larvae and to obtain basic data for taxonomic research. Specimens for this study were collected using a scoop net (aperture Ø60 cm) at the Geomun Island in Yeosu-si, Jollanam-do in July and August of 2013, and the mean water temperature was $20.6{\pm}1.84^{\circ}C$ and the mean salinity was $32.1{\pm}0.46$‰ during the collection. In post-larvae of total length 9.58~9.69 mm (average $9.63{\pm}0.04mm$, n=5), the mouth was opened, and the maxilla was shorter than the mandible. The length of the dorsal fin did not exceed that of the ventral fin, and the dorsal fin was on the same line as that of the ventral fin. In post-larvae of total length 18.0~18.5 mm (average $18.2{\pm}0.22mm$, n=5), with the growth accelerated, the pectoral fin was developed broadly and their caudal fin was differentiated into the heterocercal tail. These characteristics suggest the development of swimming ability and resultant active feeding activities. In post-larvae of total length 22.4~23.0 mm (average $22.7{\pm}0.21mm$, n=5), striped melanophores deposited in the pectoral fin, and small spot-like melanophores expanded in the processes formed on the mandible. The dorsal and anal fins were on the same line, and the anal fin was situated behind the dorsal fin.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.9-18
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• 2016

Histological and morphological development of the digestive tract of sevenband grouper were observed from after hatching to 60 days. Fishes were fed with rotifer (Brachionus rotundiformis) and chlorella (Chlorella ellipsoidea) after hatching from 2 to 20 days rotifer and brine shrimp (Artemia salina) in after 20 days rotifer, brine shrimp and semi-dry artificial diet in after 23 days. Histological and morphological development of ten larvae was observed by paraffin embedding method after fixing in 10% neutral buffered formalin. Sevenband grouper RLG showed characteristics of carnivorous fish by average 0.87. Larvae after hatching can't open the mouth and anus digestive tract was observed in a straight line following yolk sac. Larvae was observed feeding activity by opening the mouth and anus. Metamorphosis started 8 days after hatching. Esophagus divided four layer, and goblet cell was observed in esophagus, mid intestine and rectum. Larvae started cannibalism and it was caused by difference of growth. The inside of stomach was differentiated to cardiac orifice, body of stomach, pyloric stomach, and pyloric caeca. Goblet cell was observed all intestine. Gastric gland differentiated after hatching 28 days in stomach. Secretion of gastric juice was found at stomach and mucosal fold pyloric caeca. Even thought the inside of stomach expended and the number of gastric gland increased consistently and goblet cell in intestine and mucosa became longer, histochemical changes follow couldn't be found during transforming juveniles 38 days after hatching.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.489-496
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• 1992

The division, distribution and migration of the macroglial cells in the juvenile mouse brain were investigated with the radioautography. Forty mice (ICR) were randomly subdivided into two groups. The twenty mice from group 1 were weighing initially 5 to 6g, aged 10 to 12 days and were sacrificied at 2 hrs, 2, 3, 5, 7, 10, 15 and 20 days after a single intraperitoneal injection of $^3H$-thymichine ($4{\mu}$ Ci/g of body weight). Twenty mice from group 2 were weighing intially 2.5 to 5g, aged 3 to 8 days and were sacrificed at 2 hrs, 2, 3, 5. 7, 10, 15 and 20 days after a single($4{\mu}$ Ci/g of body weight) and/or after intraperitoneal repeated injections($2{\mu}$ Ci/g of body weight/interval) at 2, 3 and 5 days after the first injection. The brain preparations were processed for autoradiogrouphy using Kodak NTB-3 emulsion following development in Kodak D-19, fixation in Kodak fixer, and then stained with cresyl echt violet or hematoxylin counterstain. The labeling index of the ectodermal glial cells in the subependymal layers of the lateral ventricles (SLLV), corpus callosum (CC), molecular layer of the neocortex (MLN ), inner layer except the molecular layer in the neocortex (ILN) and medulla of the cerebrum (MC) were invested. 1. Labeling cells appeared from 2 hour and some of them sustained in the 20 day after injection. In the single injection group, the peak of the labeling index reached a 7.6% at 3 day, 3.6% at 7 day, 3.3% at 2 day, 5.0% at 3 day and 2.3% at 2 day from the SLLV. CC, MLN, ILN and MC, respectively. In the repeated injecton group, the peak of the labeling index reached a 32.0 at 7 day, 11.0% at 10 day, 89% at 7 day, 16.0% at 10 day and 10.8% at 15 day from the SLLV, CC, MLN, ILM and MC, respectively. 2 The glial cells of the SLLV were recognized as to be migrated into the CC and to be not or less to be into the MC and ILN but to be not into the MLN. Glial cell aggregates in the neocotex and MC were recognized as to be proliferated and then disappeared in the itself regions.

• Development and Reproduction
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• v.6 no.1
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• pp.37-44
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• 2002

First sexual maturity, sex ratio, spawning frequency, deposition of the egg capsules and fecundity of the female Rapana venosa(Valenciennes) inhabited in the artificially closed slag deposit area, Gwangyang Bay were investigated by histologicai and visual observations for natural living resource management. The rate of individuals reaching the first sexual maturity was 51.6％ in females measuring 7.1~8.0 cm in shell height, and 100％ in those > 10.1 cm. The total number of egg capsules per individual and the mean number of eggs in an egg capsule were 192~382 and 500, respectively. However, the number of eggs per individual and sizes of egg capsules under lower salinity and deficient food conditions in the closed slag deposit area were smaller than those under the optimum salinity and sufficient food conditions in the open regions. Fecundities of the species were approximately from 96,000 to 191,000 eggs/individual with two to low broods(spawning frequencies) during the spawning season. The duration of development in egg capsules was 18~19 days at about 18~2$0^{\circ}C$. R. venosa is a species whose embryos hatch as veliger larvae, not juvenile snail. The sex ratio of female : male was not significantly different from 1 : 1($\chi$$^2$= 0.23, p>0.05).

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.136-143
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• 2011

Early life history of the endangered species Gobiobotia brevibarba was investigated to provide baseline data for biological characteristics and restoration. Adult fish were sampled by spoon net capture at Hongcheon-gun, Gangwon-do, Korea, in April 2010. Eggs were obtained after injection of Ovarprim and were artificially fertilized by the dry method in the laboratory. The mature eggs were slightly adhesive and transparent with greyish and average $1.24{\pm}0.07$ mm in diameter. The hatching of the embryos took place about 120 h after fertilization at a water temperature of $23^{\circ}C$. The newly-hatched larva averaged $5.5{\pm}0.29$ mm in total length. Four days after hatching, they averaged $7.4{\pm}0.26$ mm in total length and their yolk sacs were completely absorbed. From 15 days after hatching, they entered the juvenile stage and reached $9.9{\pm}0.72$ mm in total length. One hundred days after hatching, their band patterns and external form were similar to those of adults, and they averaged $36.0{\pm}3.11$ mm in total length.

• Journal of Aquaculture
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• v.12 no.1
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• pp.15-24
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• 1999

From January 1997 to May, the red marbled rockfish, Sebastiscus tertius (Barsukov et Chen) was reared in the laboratory, and observed the morphological characteristies of egg and development of larvae and juveniles. The egg is spherical in shape colorless and transparent, measuring 0.72~0.80mm in diameter (mean 0.75mm, n=50). The naturally bearing larvae were 3.79~3.97mm in total length with 7~8＋15~16=22~24 myomeres, and mouth and anus were open. Melanophores were present on the yolk of the larva and ventral margins of the tail. The 1~2 days after bearing larvae measured 3.90~4.13mm in total length, and transformed to postlarval stage, and yolk sac were completely resorbed. On the lower jaw melanophores were present. Total length of the larvae was 4.23~4.60mm in total length (11 days after bearing), number of elongated pectoral fin rays was 9~10, and melanophores distributed on the top of head, around the intestine tube, ventral margins of the tail and on the pectoral fin. In 21 days after bearing, the larva were 5.83~7.10mm in total length, and the caudal notochord flex $45^{\circ}$. Individuals of 9.80~12.36mm in total length (33 days after bearing) are regarded to have reached to the juvenile stage with all the fins were developed.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.93-98
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• 1994

The pipefish Syngnathus schelegeli was reared in the laboratory from May to June 1991 and observed the morphology of eggs and larvae squeezed from the parent fish(male). The diameter of inseminated eggs ranged from 0.72 to 1.01 mm (n=50), and yolk in yellow color were found in the eggs. The newly beared larvae were 10.9 mm in average standard length and had 59~60 myomeres. In 6 days after bearing, the post larvae attained 13.8 mm in average standard length and the low jaw was developed. The larvae of 14.1 mm in average standard length (8 days after bearing) had 40~42 fin rays in dorsal fin, 9 in caudal fin and 13~14 in pectoral fin. The juvenile of 14.7 mm in average standard length (10 days after bearing) had the well elongated snout along with the opercular and caudal fin similar to adult stage's.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.89-98
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• 2014

Eggs development and early life history of the endangered Korean dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae) was investigated to provide basic information regarding biological characteristics and restoration. Adult fish specimens were sampled using a spoon net at Geurnsan-myeon, Goheung-gun, Jeollanam-do, Korea from June to July 2011. Since, spawning characteristics were analyzed, and females were induced to spawn by injecting Ovaprim (0.5 mL/kg) and their eggs were artificially fertilized with sperms by the dry method in the laboratory. Total length of mature female were 46~76 mm with GSI $9.6{\pm}3.77%$, and total length of mature male was 42~52 mm with GSI $3.5{\pm}1.04%$. Sex ratio (♂/♀) was 0.10, and there were no secondary sexual characteristics. The number of mature eggs was averaged $60{\pm}28.7$ per female. The lemon yellow eggs were slightly adhesive $1.46{\pm}0.07mm$ in diameter. The embryo hatched approximately 66 h after fertilization at $25^{\circ}C$, and the hatched larvae were averaged $5.5{\pm}0.07mm$ in total length (TL). At 6 days after hatching, the larvae averaged $9.0{\pm}0.29mm$(TL) and their yolk sac was completely absorbed. At 17 days after hatching, they entered the juvenile stage and reached $12.6{\pm}0.24mm$ (TL). At 80 days after hatching, the band patterns and external form of the juveniles were similar to those of adults, and they averaged $33.0{\pm}2.19mm$(TL).

• Korean Journal of Ichthyology
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• v.25 no.4
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• pp.200-207
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• 2013

We investigated developmental stages of egg and early life history of the Korean indigenous fish, Korean Chub Zacco koreanus from the South Han River in 2011 for phylogenetic study and conservation of this species. Eggs of Zacco koreanus were artificially fertilized by the dry method in the laboratory. The fertilized eggs were demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk, and no oil globule and average $3.09{\pm}0.07$ mm (n=10) in diameter. The hatching of the embryo took place in about 68 hrs after fertilization under water temperature of $20.0{\sim}23.0^{\circ}C$ and the newly hatched larvae were average $10.30{\pm}0.40$ mm (n=10) in total length (TL). Six days after hatching, the larvae grew up to $16.12{\pm}0.42$ mm (n=8) in TL and york sac absorption, mouth and anus opening were shown postflexion larvae stage. 17 days after hatching, most of fin-rays appeared at $18.21{\pm}0.38$ mm (n=6) in TL and brown spot appeared on the abdomen. 27 days after hatching, the larvae were brought up to $20.01{\pm}1.12$ mm(n=5) in TL and all their fin-rays were formed. 120 days after hatching, the larvae (juvenile) were $23.29{\pm}3.12$ mm (n=10) in TL and their body shape and color pattern were similar to the adult fish.

• Journal of Korean Home Economics Education Association
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• v.8 no.1
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• pp.1-10
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• 1996

This study aims at finding a new home economics education which will include male and female students as its teaching objects, and then providing home economics teachers with useful materials. For this purpose I examined analized male and female the upper secondary school students’and parents’recognition and demand to the home economics education The conclusion of this study is summarized as follows： 1. There was significant difference between male students(73.7％) and female students(89.8％) in the necessity for studying Home Economics(P＜.001). In the necessity of Home Economics education, male students emphasized the spiritual part but female students emphasized the functional part. In part of parents, there was no significant difference between fathers(95.5％) and mothers(96.4％). 2. The necessity of each part in the contents of Home Economics 1) In the part of family, there was significant difference between male and female students in the true nature of family, the role and responsibility of family, and the laws relating to family(P＜.001). There was significant difference between mothers and fathers in the true nature of family and the role and responsibility of family. Fathers and male students emphasized the true nature of family and the role and responsibility of family more than mothers and female students did. 2) In the Home management and economy parts, there was significant difference between male and female students in the significance of home management(P＜.001), the relation of family to society(P＜.001), and fluctuating measures for home economy. There was significant difference between fathers and mothers in the relation of family to society(P＜.05). Fathers and male students emphasized the relation of family to society more than mothers and female students did. Mothers, male and female students emphasized the importance of the protection of consumers. 3) In the clothes part, male students emphasized the role of clothes, the disign and making of clothes(P＜.001), the present situation of the resources of clothing and the distribution of clothes (P＜.05) more than female students did. 4) In the part of food, there was significant difference between male and female students in the kinds and function of nutritive elements(P＜.05). Parents and students emphasized the importance of selecting good food. 5) In the part of housing, male students emphasized home planning, and arrangements and facilities of house more than female students did. Female students emphasized the interior of the house(P＜.05). Fathers emphasized the planning of a residential space and arrangements and facilities of a house(P＜.05) more than mothers did. 6) In the parts of human development and upbringing, and upbringing, male students emphasized the significance of being parents, family planning and the population problem(P＜.001), pregnancy and delivery(P＜.01), and the chracteristic of juvenile development(P＜.05) more than female students did. Parents and students emphasized the importance of prevention and countermeasures for diseases and the significance of being parents.