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4. IMPLICATIONS FOR FISHERIES MANAGEMENT: SEX RATIO, SIZE AT SEXUAL MATURITY, AND REPRODUCTIVE CYCLE OF SAXIDOMUS PURPURATUS (BIVALVIA: VENERIDAE) IN KOREA

Author

Kim, Hyejin, Kim, Yeonghye, Park, Jung Jun, Jeon, Mi Ae, Lee, Yeon Gyu, and Lee, Jung Sick

Subjects
Veneridae -- Observations, Clam fisheries -- Observations, Fishery research, Biological sciences, Zoology and wildlife conservation
Abstract

This study was performed to obtain information on the sex ratio, size at sexual maturity, and main spawning period of the butter clam Saxidomus purpuratus in Korea to contribute to the management of fisheries resources of this species. The age-specific sex ratios (female:male) of S. purpuratus were 1:2.20 (31.3% female) and 1:1.03 (49.2% female) in the 0+and 1+y classes, respectively, illustrating the initially higher percentage of males in the butter clam population. From the 2+ y class onward, however, the percentage of females in the population tended to increase with age. The shell length at sexual maturity was analyzed using a logistic regression model, and was determined to be 54.5 and 45.5 mm for females and males, respectively. The gonad index displayed a definitive pattern of seasonal changes, with high values in the spring and fall and low values in the summer and winter for both males and females. The butter clam S. purpuratus was found to have two spawning seasons per year, with the main spawning period being in May-June.KEY WORDS: sex ratio, size at sexual maturity, reproductive cycle, Saxidomus purpuratus, INTRODUCTIONStudies on the reproduction of marine animals can provide information on basic biology of use in the preservation of biological resources, development of aquaculture technology, and fisheries management. These studies [...]

Published
2018
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5. Gonadal development and reproductive cycle of cultured abalone, Haliotis discus hannai (Gastropoda: Haliotidae) in Korea: implications for seed production

Author

Kim, Hyejin, Kim, Byeong Hak, Son, Maeng Hyun, Jeon, Mi Ae, Lee, Yeon Gyu, and Lee, Jung Sick

Subjects
Gonads -- Growth, Abalones -- Growth, Sexual cycle -- Physiological aspects, Shellfish culture -- Methods, Company growth, Biological sciences, Zoology and wildlife conservation
Abstract

ABSTRACT The objective of this study was to examine gonad development and reproductive cycle of the abalone Haliotis discus hannai at three main abalone aquaculture farms (Uljin, Wando, and Jeju [...]

Published
2016
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22. 日本海最西部のクモヒトデ相の予備的調査

Author

Ishida, Yoshiaki, Ohtsuka, Susumu, Takayasu, Katsumi, Kobayashi, Iwao, Lee, Yeon-Gyu, Seto, Koji, Tanaka, Hidenori, Tamura, Kazutoshi, Go, Akio, and Nakaguchi, Kazumitsu

Subjects
ophinroid, echinoderm, taxonomy, 棘皮動物, 動物地理, the Sea of Japan, 日本海, クモヒトデ, zoogeography, 分類学
Abstract

1999年11月及び2000年6月に日本海最西部の水深43-133mの海域において6科11属13種のクモヒトデが採集された。この中で5種、Ophiophrixus acanthius、Ophiocentrus koehleri、Amphiura (A.) teptobrachia、Amphiophiura pomphophora、Ophiomusium scatrareが日本海初記録であった。日本海全域からこれまでに採集されたクモヒトデ類の動物地理についても論じた。, Thirteen species of ophiuraids belonging to 6 families and 11 genera were collected at depths of 43-183 m in the westernmost part of the Sea of Japan in November 1999 and July 2000. The following 5 species, were the first record from the sea: Ophioplirixus acanthius H. L. CLARK, 1911, Ophiocentrus koehleri GISLÉN, 1926, Amphiura (A.) leptabrachia MuRAKAMI, 1942, Amphiophiura pomphophora (H. L. CLARK, 1911), and Ophiomusium scalare LYMAN, 1878. The zoogeography of ophiuroids occurring in the Sea of Japan is also discussed.

Published
2001

23. The Holocene Environmental Change of the Estuary of Nagdong River, Southern Korea

Author

Kang, Sora, Lee, Yeon Gyu, Bae, Boo-Young, Lee, Jung Woo, and Yoon, Sun

Subjects
Nagdong Estuary, micropaleontology, Holocene environment, marine transgression
Abstract

A total of 79 species of benthic foraminifera belonging to 49 genera and 60 species of diatoms belonging to 35 genera are identified from the core samples of the deltaic sediments in Nagdong Estuary. On the basis of benthic foraminiferal fauna and diatom flora, the deltaic sediments of the cores can be divided into three environmental intervals : the upper Interval I bay environment ; the middle Interval II offshore bay environment ; the lower Interval III is bay environment. The sea-water had advanced into Nagdong Estuary already earlier than 7133 yr.B.P. This marine transgression may be correlated with the Jomon Transgression in the Japanese Islands. Sea-level fluctuation occurred after around 7000 yr.B.P., which might be due to the vertical movement of the land of Nagdong Estuary.

Published
2000

40. Preliminary Faunistic Survey of Ophiuroids in the Westernmost Part of the Sea of Japan

Author

Ishida, Yoshiaki, Ohtsuka, Susumu, Takayasu, Katsumi, Kobayashi, Iwao, Lee, Yeon-Gyu, Seto, Koji, Tanaka, Hidenori, Tamura, Kazutoshi, Go, Akio, Nakaguchi, Kazumitsu, Ishida, Yoshiaki, Ohtsuka, Susumu, Takayasu, Katsumi, Kobayashi, Iwao, Lee, Yeon-Gyu, Seto, Koji, Tanaka, Hidenori, Tamura, Kazutoshi, Go, Akio, and Nakaguchi, Kazumitsu

Abstract

1999年11月及び2000年6月に日本海最西部の水深43-133mの海域において6科11属13種のクモヒトデが採集された。この中で5種、Ophiophrixus acanthius、Ophiocentrus koehleri、Amphiura (A.) teptobrachia、Amphiophiura pomphophora、Ophiomusium scatrareが日本海初記録であった。日本海全域からこれまでに採集されたクモヒトデ類の動物地理についても論じた。, Thirteen species of ophiuraids belonging to 6 families and 11 genera were collected at depths of 43-183 m in the westernmost part of the Sea of Japan in November 1999 and July 2000. The following 5 species, were the first record from the sea: Ophioplirixus acanthius H. L. CLARK, 1911, Ophiocentrus koehleri GISLÉN, 1926, Amphiura (A.) leptabrachia MuRAKAMI, 1942, Amphiophiura pomphophora (H. L. CLARK, 1911), and Ophiomusium scalare LYMAN, 1878. The zoogeography of ophiuroids occurring in the Sea of Japan is also discussed.

Published
2001

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