• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.171-179
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• 2006

Changes in the chicken testis from hatching to adulthood were studied in Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The present study was to investigate in more detail the post-hatching development of testis in Korean native chickens. Testes of chickens were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ sections stained with methylene blue-azure II, qualitative and quantitative(stereological) morphological studies were performed. Sperm production was measured by routine technique. The average volume of a testis of 1 week old Korean native chickens was determined as 0.015 g and the parameter increased linearly from 1 week to 21 weeks days (28.9 g), and did not change from 21 weeks to 64 weeks. The volume density of the seminiferous tubules increased with age from 32.6% at week 1 to 92.89% at week 64. The volume density of the interstitium represents 67.4% of the testicular parenchyma at week 1. This proportion progressively diminished during development to reach a value of 7.11% at week 64. Total sperm production per testis increased significantly from 18 weeks to 28 weeks and remained unchanged. Sperm production per 1 g testis increased significantly from 18 weeks to 28 weeks, did not change significantly from 28 weeks to 52 weeks, and declined significantly at 64 weeks of age. The average diameter of the seminiferous tubules gradually increased with age from 1 week $(42.4{\mu}m)$ to 21 weeks $(412.8{\mu}m)$. The length of the seminiferous tubules was 0.34 m at 1 week, increased significantly in subsequent age groups and reached 72.2 m by weeks 64. The stage of germ cell development in seminiferous tubules was classified as 1) spermatogonia $(1\sim8\;weeks)$, 2) spermatogonia and spermatocytes $(10\sim12\;weeks)$, 3) spermatogonia, spermatocytes and round spermatids $(14\sim16\;weeks)$, and 4) speramatogonia, spermatocytes, spermatids and spermatozoa $(18\sim64\;weeks)$. These results clarified the pattern of changes in the testicular development in Korean native chickens from hatching to adulthood as 1) neonatal-prepubertal $(1\sim12\;weeks)$, 2) puberty$(14\sim18\;weeks)$, and adult$(21\sim64\;weeks)$.

• Journal of Aquaculture
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• v.11 no.4
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• pp.529-546
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• 1998

Gonadal part that developed by indifferentiation period for 6 months after hatching is made as gonad and fat body. These gonad are thin semi-transparant and undistinguished germ cell. Germinal epithelium is distinguished by development of gonad epithelial tissue from 7 months after hatching. Sex differentiation is begun by oogonia develoment at 8 months after hatching. Primary oocytes grow over germinal epithelium of gonadal cavity, at 9 months after hatching, gonadal cavity become ovarian cavity as they increasing. As soon as oocytes at 13 months after hatching are filled with the whole part of gonad, degeneration of oocyte is begun. And then, gonad has cavity tissue, a small number of oocyte are located in gonadal cavity. At 15 months after hatching, new primary oocyte develop and cavity of ovarian tissue in the central of ovarian cavity. Spermatogonia multiplicate and cavity tissue consist of testicular tissue. These gonad become hermaphrodite and then ditermine the sex of female and male. These results show the red sea bream is juvenile hermaphrodite and undif-ferentiated gonochoristic teleost. Male and female differentiation type of gonad is divided in undifferentiation stage, oogonia-like stage, ovary-like stage, ovary development stage, hermaphroditic testis stage, hermaphroditic ovary stage, and testis development stage. Undifferentiation stage is continued total lenth 18cm at 13 months after hatching. ovary-like stage is continued total length 11~18cm at 13 months after hatching. Ovary-like stage is continued total length 14~26cm at 10~14 months after hatching. Ovary development stage begins from total length 20cm, 14 months after hatching. At 20 months after hatching, 44 percent of total sampled individuals had ovary. Hermaphroditic ovary stage first begins total length 19~20 cm at 15 months after hatching, but it is not observed total length 28~29cm at 20months after hatching. Hermaphroditic testis stage first begins total length 21~22cm at 20months after hatching and is continued for 20months. Testis development stage first begins total length 20~21cm at 20 months after hatching, and is occupied 33 percent total length 28~29cm at 20 months. The beginning of sex differentiation more than 50 percent is from total length 16cm at 11 months after hatching. Sex determination begins total length 20cm, 14months after hatching in female and total length 20cm, 15 months after hatching in male. Sex determination more than 50 percent begins total length 23cm,, 17 months after hatching. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks. This appearence is showed the same tendency in 3-year old red sea bream. 1.9mm larvae after hatching grow about 19mm larvae for 47 days. The relationship between the total length and body weight of larvae and juveniles in $BW=4.45{\times}10^{-6}TL^{3.4718}$ r=0.9820. Fishes in cage culture grow to maximum total length 28.4cm. The relationship between the total length and body weight of these fishes is $BW=2.36{\times}10^{-2}TL^{2.9180}$, r=0.9971. Undifferentiated gonadal part of red sea bream consist gonad and fat body. As differentiation is going on and gonad is growing, fat body shrinks.