• 한국어류학회지
• /
• 제12권2호
• /
• pp.129-136
• /
• 2000

1998년(年) 2월(月)부터 5월(月)까지 매월 1회 전라남도 장흥군 유치면 단산리, 부산면 지천리 및 용반리에서 자연산란(自然産卵)한 난(卵)과, 반두를 이용하여 채집한 꺽저기 어미를 여수대학교 자원생물실험실로 운반하여 사육수조에서의 산란습성(産卵習性)과 난발생과정(卵發生過程) 및 자치어(仔稚魚) 형태변화를 관찰하였다. 1. 산란기(産卵期)는 자연(自然)에서는 4월(月)에서 5월(月)까지 였고, 인위적인 수조 안에서 한쌍의 어미가 2~3회에 걸쳐 산란(産卵)을 하였으며, 이후 수컷이 수정란(受精卵)에서부터 부화(孵化) 후 10일까지의 자어(仔魚)를 보호(保護)하였다. 2. 꺽저기의 수정란(受精卵)은 구형(球形)의 심성점착란(沈性粘着卵)으로 투명한 황색을 띄면서 알의 크기는 2.21~2.65 mm (평균 2.44 mm, n=10)로 여러개의 유구(油球)를 가지며, 유구(油球)의 크기는 0.058~0.343 mm였다. 3. 사육수온 $18{\sim}22^{\circ}C$에서 수정(受精)후 194시간 23분 만에 부화(孵化)가 시작되었다. 4. 부화(孵化)직후 자어(仔魚)의 전장은 5.09~5.68 mm (평균 5.38 mm, n=10)로 큰 난황(卵黃)과 난황(卵黃)의 앞쪽에 유구(油球)가 위치하였고, 입과 항문이 열려있었으며, 눈에는 색소포(色素胞)가 착색(着色)되었다. 5. 부화(孵化) 후 5일째 자어(仔魚)는 전장 6.12~6.68 mm (평균 6.47 mm)로 난황(卵黃)을 완전 흡수하여 후기자어기(後期仔魚期)로 이행하였고, 각 지느러미의 원기가 출현(出現)하였으며, 흑색소포(黑色素胞)는 머리 위부분파 꼬리 부분에서 2~3개의 띠 모양으로 형성되었다. 6. 부화(孵化)후 22일째 자어(仔魚)는 평균전장 11.54 mm로 각 지느러미가 정수에 달하였으며, 체측에 5~7줄의 가로 무늬 띠가 형성되었다. 7. 부화(孵化) 후 32일째 개체는 평균전장이 13.05 mm로 체측에 5~6개의 세로무늬 띠, 7~8줄의 흑갈색 가로띠 및 머리부분에 5~7줄의 방사상의 줄무늬가 나타나 치어기(稚魚期)로 이행하였으며, 이 시기의 치어(稚魚)는 체형과 반문이 성어와 닮아 있었다.

• 한국패류학회지
• /
• 제30권4호
• /
• pp.333-342
• /
• 2014

Ultrastructural studies of oogenesis in oocytes, oocyte degeneration associated with the follicle cells in female Coecella chinensis were investigated for clams collected from Namhae, Geongsangnam-do, Korea. In this study, vitellogenesis during oogenesis in the oocytes occured by way of endogenous autosynthesis and exogenous heterosynthesis. Of two processes of vitellogenesis during oogenesis, the process of endogenous autosynthesis involved the combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum. whereas the process of exogenous heterosynthesis involved endocytotic incorporation of extraovarian precursors at the basal region of the oolema of the early vitellogenic oocytes prior to the formation of the vitelline coat. It is assumed that the follicle cells were involved in the development of previtellogenic and early vitellogenic oocytes and appear to play an integral role in vitellogenesis in the early and late vitellogenic oocytes by endocytosis of yolk precursors, and also they were involved in oocyte degeneration by assimilating products originating from the degenerated oocytes, thus allowed the transfer of york precursors needed for vitellogenesis (through phagocytosis by phagolysosomes after spawning). Follicle cells presumably have a lysosomal system for breakdown products of oocyte degeneration. and for reabsorption of various phagosomes (phagolysosomes) in the cytoplasm for nutrient storage during the period of oocyte degeneration.

• 수산해양기술연구
• /
• 제51권1호
• /
• pp.35-41
• /
• 2015

The age and growth of the Marbled sole, Pleuronectes yokohamae were investigated using left sagittal otoliths of 832 individuals collected in the mid-southern waters of Korea from January 2006 to April 2007. The seasonal changes in the ratio of an translucent zone to interval between annular rings revealed that the boundaries between translucent and opaque parts of the otolith were annual growth rings formed between May and June once a year. The spawning period was November to March and therefore the duration from fertilization to the complete formation of the annual growth ring became fifteen months. The parameters of von Bertalanffy growth equations estimated using the average standard length at each age are the $L_{\infty}$ of 48.04cm, K of 0.1406/year and $t_0$ of -0.5116 for female and 26.14cm, 0.3056/year and -0.8202 for male, respectively. Finally, it is suggested that the growth of female is faster than that of male from age-2.

• 수산해양기술연구
• /
• 제54권3호
• /
• pp.204-216
• /
• 2018

A study for species composition and abundance of the fish assemblages in the coastal Sacheon Bay, Korea were conducted using monthly collection by a shrimp beam trawl from March 2015 to February 2016. The number of individuals, biomass and species diversity indices fluctuated with the station and month. Of all 73 species collected, the dominant species in terms of numbers were Liparis tanakae, Zoarces gillii, Amblychaeturichthys hexanema, Ricuzenius pinetorum and Pleuronichys cornutus. The peak number of fishes occurred in March and April, whereas the biomass of fishes was highest in April. The numbers and biomass of fishes were lower in February corresponding with the low temperature, and diversity indices were highest in June. Due to those seasonal difference in abundance of the dominant species, fish community were divided into three main groups. In addition, seasonal difference by station of fish community were devided into four main groups. Juvenile fishes of coastal Sacheon were presented during the study period. It presented that the study area served as an important role in spawning and nursery ground for fisheries resource.

• 환경영향평가
• /
• 제18권3호
• /
• pp.185-193
• /
• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.

• 한국패류학회지
• /
• 제4권1호
• /
• pp.30-41
• /
• 1988

The gonadal development, the annual reproductive cycle and the first sexual maturity of surf clam, Mactra veneriformis Reeve were studied histologically. Speciemens were monthly collected at the intertidal zone of Naechodo, Chollabuk-do, Korea, for one year from March 1986 to February 1987. Sexuality of the clam is dioecious. The gonads were located between the subregion of mid-intestinal gland in the visceral cavity and the reticular connetive tissues of the foot, The ovary is composed of a number of ovarian sacs, and the testis comprise several testiculat lobules. The undifferentiated mesenchymal tissues and eosinophilic granular cells function as nutritive cells in the early stage. The ripe eggs were about 50-60${\mu}{\textrm}{m}$ in diameter, and they were wurroundedby the gelatinous membranes. The spawing period was from early June to September the main spawning occurred beetween July and August when the water temperature reached above 24$^{\circ}C$. The annual reproductive cycle of this species could be classified into five successive stages: multiplicative(January to March), growing(March to May), mature(April to August), spent(June to September), degenerative and resting(September to February). The monthly changes of fatness coefficient closely correlated with the annual reproductive cycle. Percentages of the first sexual maturity of female and male clams were over 50% among those individals ranging from 2.1 To 2.5cm, and 100% in those over 2.6cm in shell length.

• 한국어류학회지
• /
• 제7권2호
• /
• pp.171-176
• /
• 1995

경남 통영시 산양면 연안에서 1992년 12월부터 1993년 11월까지 채집한 그물베도라치의 연령과 성장을 조사하였다. 연령형질은 이석을 사용하였고, 윤문(輪紋)은 불투명대에서 투명대로 이행하는 경계로 하였다. 윤문(輪紋) 형성시기는 11월경이었고, 년(年) 1회 형성되었다. 산란기는 1월에서 3월로 추정되었고, 주산란기는 2월이었다. 따라서 초륜이 형성되기까지 소요되는 기간은 0.75세였다. 그물베도라치의 체장성장식은 $L_t=23.5977(1-e^{-0.2542(t+2.1302)})$, 체중성장식은 $W_t=64.5892(1-e^{-0.2542(t+2.1302)})^{2.3002}$으로 추정되었다.

• 수산해양기술연구
• /
• 제49권3호
• /
• pp.261-269
• /
• 2013

The age and growth of the Pacific cod, Gadus macrocephalus were investigated using left sagittal otoliths of 682 individuals collected in the West Sea of Korea from January to December 2007. The seasonal changes in the ratio of an opaque zone to interval between annular rings revealed that the narrow translucent parts of the otolith were annual growth rings formed between February and March once a year. The spawning period was December to January and therefore the duration from fertilization to the complete formation of the opaque zone became thirteen months. From the parameters calculated using the average length when the year ring was formed, the estimated von Bertalanffy growth equations were $L_t=100.0(1-e^{-0.1640(t+0.5247)})$ for females and $L_t=64.6(1-e^{-0.3335 (t+0.3342)})$ for males when is total length in age t.

• 한국양식학회지
• /
• 제8권1호
• /
• pp.21-29
• /
• 1995

수정 10분후에 수온 $28^{\circ}C$에서 15분간 처리로 산천어, Oncorhynchus masou 3배체를 유도하였다. 혈액학적 및 생리학적 특성 조사가 3배체와 2배체를 대상으로 산란기전에 실시되었다. 적혈구 수에서 3배체는 2배체에 비해 유의하게(P< 0.01) 낮은 반면 산소 소모, haematocrit치, hemoglobin, 적혈구 부피, MCH 및 MCHRBC에서는 3배체가 2배체에 비해 높게 나타났다 Total protein, albumin 및 cholesterol에서도 역시 3배체는 2배체에 비해 높게 나타났다.

• 한국수산과학회지
• /
• 제35권6호
• /
• pp.557-562
• /
• 2002

This study was to estimate population growth parameters of the freshwater bivalve, Corbicula (Corbiculina) papyacca (Heude) in Korea. Samples were collected from Jojong stream in Chungpyeong from September 1999 to August 2000. Ages were determined from the ring of shell, The shell length of the samples ranged from 4,2 mm to 28.1 mm, The ring on the surface of shell was formed once a year from January to March, Marginal increment analysis of shell rings indicated that annuli were formed in June. Spawning period was estimated to be May to August with a peak between June and July through fatness analysis, and thus rings were considered to be true annual marks. Von Bertalanffy's growth parameter were estimated from a nonlinear method with the value of logical maximum shell length ($L_{propto}$) was 34,36 mm, K was 0.1531/year, logical age of shell length 0 ($t_{0}$) was -0,5246 year, and logical maximum total weight ($W_{propto}$) was 11.42 g.