• Title/Summary/Keyword: spawning period

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Maturation and Spawning of the Pacific Cod Gadus macrocephalus in the West Coast of Yellow Sea of Korea (한국 서해에 출현하는 대구(Gadus macrocephalus)의 성숙과 산란)

  • Choi, Dong Hyuk;Youn, Byoung Il;Kim, Maeng Jin;Lee, Seung Hwan;Lee, Seung Jong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.1
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    • pp.46-52
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    • 2021
  • The maturation and spawning of Pacific cod Gadus macrocephalus were inversigated using 2,415 samples collected monthly from January 2017 to December 2019, in the Yellow Sea of Korea. We analyzed monthly changes in gonadosomatic index (GSI), maturity stage, egg diameter (mm), the relations fecundity and total length (cm). The spawning period was February to March. Fecundity varied between 334,836 and 2,099,600 eggs. The relationship between the fecundity and TL of fish was expressed in F=186.86TL2.0954 (R2=0.7359). The percentage of sexually mature females estimated from a logistic function was over 50%, 75% and 97.5% for the size (TL) 39.3, 44.8 and 57.7 cm.

Maturity and Spawning of the Pointhead Flounder Cleisthenes pinetorum in the West Sea of Korea (한국 서해에 출현하는 용가자미, Cleisthenes pinetorum 암컷의 성숙과 산란)

  • Choi, Dong Hyuk;Youn, Byoung Il;Lee, Seung Hwan;Kwon, Dae Hyeon;Kim, Maeng Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.5
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    • pp.575-582
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    • 2022
  • This study revealed the reproductive biology of pointhead flounder Cleisthenes pinetorum, in the middle of the West Sea of Korea. We collected samples using gill net and drag net fisheries in coastal waters from January to December 2019. Mmonthly gonodosomatic index and maturity stage results showed that the spawning period was October to December, and the females grew faster than the males. The fecundity ranged from 16,728 to 1,039,616 number of eggs, and the relationship between TL and fecundity (F) was 0.0000003TL4.7434 (R2=0.4898). The size-frequency distribution of eggs suggested that C. pinetorum spawm once during a spawning period. The length at 50% maturity for females was estimated to be 18.9 cm.

Maturity and Spawning of the Greenling, Hexagrammos otakii in Coastal Waters near Incheon, Korea (인천 연안에 서식하는 쥐노래미(Hexagrammos otakii)의 성숙과 산란)

  • Seung Hwan Lee;Tae Hyoung Roh;Dea Hyeon Kwon;Dong Hyuk Choi
    • Korean Journal of Ichthyology
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    • v.35 no.4
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    • pp.333-339
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    • 2023
  • The aim of this study was to collect information regarding the sex ratio, size at sexual maturity, and the primary spawning period of Hexagrammos otakii. The sex ratio (female : male) was observed to be 1 : 1.2 (n =739 : 906, with females comprising 81.6% of the population). The gonadosomatic index (GSI) exhibited its highest values in November for females and October for males, coinciding with the primary spawning period from November to January. The total length required for 50% sexual maturity was determined through a logistic regression model and found to be 23.1 cm for females.

The Effect of Broodstock Age on the Spawning Performance of Cultured Haliotis discus hannai

  • Kim, Byoung-Hak;Kang, Kyoung-Ho;Zhang, Zhi-Feng;Kim, Jae-Min;Kim, Jan-Di
    • The Korean Journal of Malacology
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    • v.19 no.2
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    • pp.107-110
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    • 2003
  • The effect of broodstock age on the spawning performance of cultured abalone, Haliotis discus hannai, was assessed for five age groups (3, 4, 5, 6, 7 years old). Spawning performance of the five age groups was assessed in terms of the percentage of spawning abalone, eggs per spawning female, fertilization rates, hatch rates and attachment rates per spawning. The percentage of spawning abalone increased along with broodstock age, reached maximum in female groups of 5- and 6-year age (60%), and in male group of 6-year age (100%), subsequently decreased in 7-year age group. The number of eggs produced per spawning also increased with broodstock age, and the maximum was found in 6-year age. Although the number of spawned eggs for the oldest abalone declined, it still spawned much more eggs than 3, 4, and 5 years old females. The fertilization and hatch rates were obviously larger for 4-6 years old group than the younger and older abalones. The maxima were found in 5-year age group (96.0% and 84.5%), and the minimum were appeared in 7-year age group (79.3% and 58.2%). The attachment rate increased with broodstock age, reached maximum in 6-year age group (33.6%), although the increment gradually declined. The attachment rate for 7-year age group rapidly decreased (16.6%). These results suggested that broodstock age affected the spawning performance of H. discus hannai, which peaked between 5 and 6 years old, and broodstock should be bred during this period for hatchery production.

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Comparison of Carotenoid Pigments on Korean Dark Sleeper, Odontobutis platycephala and Dark Sleeper, Odontobutis odontobutis interrupta in the Family Eleotridae (구굴무치과에 속하는 동사리와 얼룩동사리의 Carotenoid 색소성분의 비교)

  • 하봉석;김명선;백승한;김현영;김수영;정계임;권문정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.813-820
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    • 1998
  • This study was performed as a part of comparative biochemical studies of carotenoid pigment for the fresh water fish. Carotenoids in integument of Korean dark sleeper, Odontobutis platycephala, and dark sleeper, Odontobutis odontobutis interrupta, which are all the Korean native fresh water fish, were separated by thin layer chromatography, column chromatography and HPLC. The separated carotenoid were then reduced and isomerized by NaBH4 and I2 respectively to investigate UV-Vis spectrophotometeric patterns and chracterized by IR, 1H-NMR and Mass spectrum. The content of total carotenoids in the integument of Korean dark sleeper was 3.01mg% in April, but it was increased to 3.74mg% in September at the near of spawning period. The carotenoid isolated in April consisted of $\beta$-carotene(25.6%), lutein(18.5%) and zeaxanthin(12.0%) as major carotenoids and also contained isocryptoxanthin, diatoxanthin, tunaxanthin, cynthiaxanthin, canthaxanthin and $\alpha$-cryptoxanthin as minor carotenoids. Similarly, in September the carotenoid consisted of $\beta$-carotene(16.5%), zeaxanthin(13.7%) and cynthiaxanthin(13.6%) as major carotenoids and also contained lutein, isocryptoxanthin, tunaxanthin, $\alpha$-cryptoxanthin, diatoxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of cynthiaxanthin and $\alpha$-cryptoxanthin were increased. The content of total carotenoids in the integument of spawning period. T도 carotenoid isolated in April and September consisted of $\beta$-carotene(24.9%, 27.5%), zeaxanthin(14.4%, 20.9%) and lutein(12.6%, 11.4%) as major carotenoids and also contained cynthiaxanthin, tunaxanthin, diatoxanthin, isocryptoxanthin, $\alpha$-cryp-toxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of zeaxanthin was increased, indicating that the carotenoid composition were dependent upon their living conditions and their integument colors. Both Korean dark sleeper and dark sleeper contained high amount of cynthiaxanthin and diatoxanthin which are found as rare carotenoids in the other of fresh water fish. It is interes that they also contained tunaxanthin which is a specific carotenoid in marine fishes.

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Sexual Group Maturity and Main Spawning Period of Glyptocephalus stelleri (Teleostei: Pleuronectidae) (기름가자미 Glyptocephalus stelleri의 군성숙도와 주 산란기)

  • Shin, So Ryung;Kim, Hyeon Jin;Oh, Han Young;Lee, Jung Sick;Song, Hyejin;Kim, Jae Won
    • Journal of Marine Life Science
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    • v.7 no.1
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    • pp.37-44
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    • 2022
  • This study was performed to obtain information on the sex ratio, size at sexual group maturity, and main spawning period of Glyptocephalus stelleri. The sex ratio (female: male) was 1:0.54 (n=189:103, 64.7% female), and the frequency of females in the population tended to increase with total length. The oocyte development pattern was group synchronous development, in which oocyte groups at different stages were identified within the same ovary. The total length at 50% sexual group maturity was analyzed using a logistic regression model, and was determined to be 28.51 (female) and 30.49 cm (male). The gonadosomatic index (GSI) displayed the highest values in April (female) and March (male), and the main spawning period being in April to May.

Analysis of the characteristics of the environment and fish community in the Gwanggyo Lake Park area using the environmental DNA technique (환경 DNA 기법을 활용한 광교호수공원 일대의 시기 및 수환경 특성별 어류상 분석)

  • Won, Su-Yeon;Kang, Yu-Jin;Song, Young-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.5
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    • pp.77-88
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    • 2022
  • This study aims to understand the relationship between the distribution of fish species in the two water ecosystems and the habitat factors according to the survey period targeting Gwanggyo Lake Park in the city. There are studies on the appearance and distribution of species by applying eDNA to freshwater ecosystems. However, in the domestic, streams are the target, and studies on the relationship between species distribution and habitat environment in two water environments are lacking. We conducted to analyze the species list and relationship with habitat factors using eDNA research in May and October at 21 points in Gwanggyo Lake Park, Suwon City, which were connected to lakes and streams. As a result, there was no species difference in the water environment according to the survey period. However, the total number of reads during the spawning season(May) was 3,126,482, which was more than double that after the spawning season(October). Tolerant species appeared in Woncheon Lake with a slow or stagnant flow, but there was no significant correlation between species and habitat factors depending on the survey period. On the other hand, intermediate and sensitive species appeared in the Woncheon stream with high flow. There was a significant correlation between the low temperature during the spawning season and the high dissolved oxygen content after the spawning season(P<0.001, Tem.: 20.7±2.6℃, DO: 8.6±1.7). It is expected that environmental DNA will be used to survey species and suggest monitoring methods according to the survey period.

Spawning, Hatching, Survival and Cannibalism of Octopus ocellatus (주꾸미 (Octopus ocellatus)의 산란과 부화, 생존 및 공식)

  • 김병균;정의영;전제천;정치홍
    • The Korean Journal of Malacology
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    • v.17 no.2
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    • pp.85-94
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    • 2001
  • Spawning, hatching, survival and cannibalism of the octopus, Octopus ocellatus, were investigated at the indoor laboratory. The specimens were collected in the coastal waters of Puan, Korea, from March 2000 to May 2001. Changes in the gonadosomatic index (GSI) during March to May, 2000 were similar to those in 2001. The GSI began to increase in March and reached the maximum in May 2000 and 2001. The mean fecundity of adult individuals in April was larger than those in March and May in 2000 and 2001. In the investigations of survival rates of adults according to the water layers, the mean survival rate in the middle water layer was higher than that in the bottom layer in year 2000 (p = 0.002). The survival rate during 2001 was similar to the result of year 2000 in the water layers (p = 0.018). From the investigations with the purchase dates, the survival (88.8%) in the early spawning period (April 10, 2000) showed larger than those in the mid-spawning (May 11, 2000) and the late spawning (May 23, 2000). For aquaculture, it is suggested that the purchase timing of adults in the early spawning period will have a better result than that of the other spawning periods. In the amount of spawning with water layers, the number of eggs spawned of the adults in the middle layer were larger than those in the bottom layer. In the number of eggs spawned with the purchase dates, the number of eggs spawned in the early spawning period were larger than those in the middle and late spawning periods. The size of eggs spawned were 6.904$\times$2.520 mm. the hatching period required (from spawning to hatched larvae) was 55 days (April 17 to June 7,2000) at water temperatures of 11.2 to 21.1$^{\circ}C$. In case of the hatching rates with water layers, the hatching rate in the middle water layer was larger than that in the bottom one (p = 0.004).

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Spawning and Egg Development of a Polychaete, Perinereis aibuhitensis Reared at Indoor Tanks (수조사육에 의한 청충, Perinereis aibuhitensis (Grube)의 산란과 난발생)

  • 강경호;이재학;장영진;유성규
    • Journal of Aquaculture
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    • v.10 no.1
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    • pp.17-24
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    • 1997
  • In order to understand the spawning and larval development of Perinereis aibuhitensis for the effective seedling production, the influence of water temperature on spawning induction, egg and larval development of the worm were investigated from October 30, 1989 to October 30, 1990. Main spawning period was from July through September, and average diameter of mature eggs was $220\mu m$. The relationship between the adult weight (Wt) and the number of spawned eggs (NS) was given as follws : NS=48635.589Wt1.3044 (r=0.8572). Adult males and females died immediately after spawning. Trochophore larvae developed 12 hours after fertilization, and hatched out after 56 hours.

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Distribution of Walleye Pollock, Theragra chalcogramma, Spawning in Shelikof Strait, Gulf of Alaska, Based on Acoustic and Ichthyoplankton Surveys 1981, 1984 and 1985 (알라스카만 쉘리코프 해협에서 산란하는 명태, Theragra chalcogramma,의 분포에 대하여 : 1981, 1984~85년의 음향학적 조사 및 난치자어 조사)

  • KiM Suam;NUNNALLEE Edmund P.
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.6
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    • pp.425-438
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    • 1990
  • Acoustic and ichthyoplankton data collected from Shelikof Strait in 1981, 1984 and 1985 were examined to determine spawning ground and period of walleye pollock, Theragra chalcogramma. Walleye pollock in the Gulf of Alaska migrated into Shelikof Strait for spawning during late winter and early spring. They entered Shelikof Strait via the warm and saline deep layer (continental slope water mass) in the southwestern channel, and major fish schools concentrated for spawning along the deep trough (250~300m) in the western part of the central strait. Peak spawning activity occurred there from late March to early April. Peak spawning time and area in Shelikof Strait varied little between years, despite difference in hydrography. Geographical advantages together with some oceanographic phenomena (reduced water transport and reduced mixed layer depth in spring) made that area an optimal spawning ground in the Gulf of Alaska during early April. After early April, spawning intensity decreased rapidly and the spawning area tended to expand to the northeast and southwest.

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