본 연구는 바지락의 기초 생물, 생태학적 정보의 하나로써, 수온 및 염분의 변화가 바지락의 여과율에 미치는 영향을 파악하기 위하여 수행되었다. 실험에 사용된 바지락은 전남 여수시 화양면에 위치한 갯벌에서 채집하여 사용하였고, 먹이생물은 규조류, Phaeodactylum tricornutum을 실내에서 단일종 배양하여 사용하였다. 여과율측정은 간접측정법을 사용하였고 먹이생물의 농도는 광학현미경하에서 혈구계산판을 이용하여 직접 계수하였다.Salinity (psu)Temperature range (℃)Q10one-yearclasstwo-yearclassthree-yearclass155-1514.7124.3542.51110-205.2171.3082.18215-251.3221.1871.33420-300.4160.8181.07425-350.2670.4350.550
The present study was performed to describe the influence of water temperature and salinity on the filtration rates of the short-necked clam, Ruditapes philippinarum. The clams were collected at tidal flat near Yeosu city, Cheollanamdo, Korea, from July 2001 to August 2001. Diatoms, Phaeodactylum tricornutum (KMCC B-128), were indoor-cultured by f/2 medium, and were used to measure the filtration rate of the clams. Filtration rates of the clams were measured by indirect method. Cell concentrations of food organisms were determined by direct counting cells using the hemacytometer under the light microscope. The filtration rate of the clams increased with temperatures up to the optimum temperature, circa 25℃. Above this optimum temperature, the filtration rate decreased drastically. Also the filtration rate of the clams increased with salinity up to 35 psu. The maximal filtration rates of the clams were recorded at 20-25℃, similar to be known as the optimal temperature for their growth, and 25-35 psu, respectively. The minimal filtration rates of the clams were recorded at 5℃ and 15 psu. At the similar temperature and salinity, the filtration rate of the younger clams was higher than that of the older ones. Thermal coefficient, Q10 values at low temperature range were much higher than those at high temperature range. These results indicate the short-necked clam is more sensitive in cold water. As they grow up, they become more stronger against their ambient environmental changes, such as thermal-shock, salinity changes.
1999년 1월부터 12월까지 한국 보령 연안에 서식하는 살조개 (Protothaca jedoensis) 를 대상으로 생식소지수, 생식소 성숙 및 산란에 따른 생식주기, 산란기, 군성숙도, 그리고 성비 등 생식생태를 조사하였다. 생식소는 내장낭의 간중장선 외측을 둘러싸고 있는 외벽 근섬유막으로부터 족부의 외벽근 섬유막 사이에 있는 망상결체 조직층 사이에 다수의 소낭 또는 세관으로 분포하였다. 난소는 수많은 난소소낭으로, 정소는 다수의 정소세관들로 구성되어 있다. 암수의 생식소지수 (GI) 의 월별 변화는 2월부터 점진적으로 증가하기 시작하여, 5월에 최대에 이른 후 6월부터 급격히 감소하여 11월에 최소에 이르고 있어 생식주기의 변화와 유사하였다. 본 종의 산란기는 1년에 1회로 5-7월사이에 일어나며, 산란성기는 해수 수온이 20℃ 이상인 6월과 7월사이 이었다. 살조개 암수의 생식주기는 초기활성기 (12-3월), 후기활성기 (2-5월), 완숙기 (4-7월), 부분산란기 (5-8월), 퇴화 및 비활성기 (7-1월) 의 연속적인 5단계로 구분할 수 있었다.암수 개체의 군성숙도 (%) 는 각장 30.1-35.0 mm 인 경우 군성숙도 (%) 는 각각 52.6%와 60.0%이었고, 각장 45.1 mm 이상인 암, 수 개체들의 성비는 1:1로 유의한 차를 보이지 않았다(χ2 = 0.40, p > 0.05).감사의 말씀자료 정리 및 원고 작성을 위해 도움을 준 군산대학교 대학원생 최기호군에게 감사드리며, 본 연구는 군산대학교 수산과학연구소 2002년도 학술 지원 연구비의 일부 지원으로 수행되었습니다.
The gonad index (GI), reproductive cycle with gonad developmental phases, first sexual maturity and the sex ratio of the jedo venus, Protothaca jedensis, on the coastal waters of Boryeong, Korea were investigated by histological study. Samples were collected from the subtidal zone of Boryeong, Korea from January to December, 1999. Monthly changes in the gonad index in femal and male clams gradually increased from February and reached the maximum in May, and then the values rapidly decreased from June and reached the minimum in November as seen in variations of the reproductive cycle. The spawning period of this species was once a year between May and July, there was a spawning peak between June and July when seawater temperature was over 20℃. The reproductive cycle of this species in female and male clams can be classified into five successive stages: early active stage (December to March), late active stage (February to June), ripe stage (April to July), partially spawned stage (May to July) and spent/ inactive stage (July to January). Percentages of first sexual maturity of female and male clams of 30.1-35.0 mm in shell length were 52.6% and 60.0%, respectively, and 100% for the clams over 45.1 mm in shell length. The sex ratio of individuals > 30.1 mm in shell length was 1:1 (χ2 = 0.40, p > 0.05).
중국에서 이식하여 어미패로 양성한 해만가리비를 수온 17.1-23.2℃로 44일간 Isochrysis galbana 등 5종의 먹이생물을 혼합시켜 공급하면서 성숙을 유도하여, 1997년 1월 29일 및 31일 2회에 걸쳐 간출과 수온 자극을 가하여 총 4,532만개의 수정란 (평균 52 μm) 을 채란하였다. 난 발생 단계를 조사한 결과, D형 유생의 크기는 평균 77.5 × 63.8 μm이었고, 부착기 유생은 191.8 × 181.2 μm의 크기였으며, 부착기 유생은 이 크기에서 파판에 부착하여 치패로 발달하였다. 이 치패는 2월 14일부터 5월 7일까지 수온 22.8-26.3℃, 염분 31.0-34.4에서 실내 사육한 결과, 평균 각장 3.04 mm로 성장하였다. 비단가리비의 경우는, 부착기의 부착유생들은 채묘기(collector) 에서 떨어지면 폐사하게 되는데, 이것은 Argopecten balloti에서 나타나는 바와 같이, 족사에 의한 부착기간이 짧아서가 아니라 부착유생들이 각기 소수의 족사를 가지기 때문에 채묘기에 대한 부착력이 약하여 부착유생의 생존율이 비교적 낮았던 것으로 사료된다.
Artificial spawning, larval and spat developments of the bay scallop, Argopecten irradians, which was transplanted from China on 16 August 1996, were investigated monthly until August 1997 in the Deukyang Bay, Jangheung-gun, Jeollanam-do, Korea. Sufficient amount of cultured microalgae supplemented seawater were supplied as food (6 kinds of phytoplankton) for fully grown adult individuals at 17.1-23.2℃ for 44 days. A total of 45,320,000 eggs were spawned by way of 2 times of artificial spawning inductions such as exposure stimulus to the air and thermal shock (with water temperature) on 29 January and 31 January in 1997. Artificially fertilized eggs were developed to D-shaped larvae (77.5 × 63.8 μm) and metamorphosed to larvae (191.8 × 181.2 μm) in the attached larval stage on the collectors. A total of 110,000 spats (average 3.04 mm in shell length) were produced at 22.8-26.3℃ and 31.0-34.4 psu in the indoor rearing tank from 14 February through 7 May in 1997. In case of Argopecten irradians, if the attached larvae in the attachment stage are detached from the collector, they could not live. Accordingly, it is assumed that survival (%) of the attached larvae of A. irridians showed very low because of weak power attached to the collector due to the small number of the byssuses of the attached larva, not the short attachment period by the byssus as seen in other scallops such as Argopecten balloti.
To know the effects of the red tide and toxic dinoflagellates on survival and growth of larvae of the mussel, Mytilus galloprovincialis, laboratory experiments were conducted by incubating larvae with either unialgal culture of 4 dinoflagellate species (Amphidinium carterae, Prorocentrum triestinum, Gymnodinium impudicum, or Akashiwo sanguinea) or a standard food (Isochrysis galbana) for 10 days. The survival of larvae was higher than 80% when the food was A. carterae, G. impudicum, or A. sanguinea. The lowest survival (20%) was found when the food was P. triestinum. When the food was P. triestinum, the survival of larvae rapidly decreased from 87% at day 4 down to ca. 50% at day 6, and 20% at day 10. This implies that the larval population of M. galloprovincialis can seriously be affected if they are exposed to the red tide water dominated by P. triestinum for more than 4 days. Shell length of larvae either increased or decreased according to the food species. When the food was A. carterae, G. impudicum, or A. sanguinea, shell length of larvae increased. But, it decreased when the food was P. triestinum. Though shell length increased in 3 treatments, the daily increments (0.63 <TEX>$\mu$</TEX> m for A. carterae, 0.46 m for <TEX>$\mu$</TEX> G. impudicum, and 1.10 m for <TEX>$\mu$</TEX> A. sanguinea) were smaller than that of the standard food (3.79 m for <TEX>$\mu$</TEX> I. galbana). Correlation analyses chowed that the change in shell length was not significant when the food was A. carterae or G. impudicum. Therefore, all of 4 dinoflagellates affected the growth of M. galloprovincialis larvae: growth was negative for P. triestinum, nil for A. carterae and G. impudicum, and positive but lower than standard food for A. sanguinea. These imply that the dinoflagellates are less valuable as foods for M. galloprovincialis larvae. So, decreased growth rate of larvae is expected during red tides, which will consequently cause delayed metamorphosis or failure to recruitment to the adult populations. In considering the harmful effects of red tides on the aquatic ecosystem, not only the effects on adult populations of fish and shellfish, but also the effects on larval populations should be included.
To obtain the basic information on culture conditions for the larvae of Saxidomus purpuratus, experiments were conducted on the population from southern coast for (1) the success in fertilization and development from artificial fertilization among different months of a year, (2) the viability of sperms after exposure to seawater, (3) and the effects of temperature, salinity, and food organism on the survival and growth of larvae. Gametes obtained from dissection showed high rate of fertilization at all months. But the rate of development was higher only May-July. Developmental success seemed to be related with the quality of eggs at the time of fertilization. Developmental times for 2-cell, 4-cell, 8-cell, blastula, trochophore larva, and veliger larva at 20<TEX>$^{\circ}C$</TEX> were 1.5, 2, 4, 18, 24, and 32 hr, respectively. Sperms could survive for more than 8 hr, however, actively swimming sperms could be found within 1 hr after exposure to seawater. It is recommended that sperms should be used for fertilization as soon as possible when they are exposed to seawater. At temperature of 35<TEX>$^{\circ}C$</TEX>, all the larvae died during 48 hr. Larval survival decreased when salinity was either lower than 20 psu or higher than 40 psu, and was 0% when salinity was 10 psu. Optimal range of temperature and salinity for rearing larvae of S. purpuratus were 20-25<TEX>$^{\circ}C$</TEX> and 20-40 psu, respectively. Larvae grew from 111.5 to 235.3 <TEX>${\mu}$</TEX>m during 21 days. Larvae fed mixed diets grew faster than unialgal diets. The fastest growth was observed when larvae were fed on the mixture of Isochrysis galbana and Nannochloris oculata.
바지락, Ruditapes philippinarum의 생식기구를 밝히기 위한 연구의 일환으로서 생식주기는 조직학적 관찰에 의해 조사되었고, 폐각근 조직 및 내장낭 조직 내의 생화학 성분들은 생화학적 분석방법에 의해 조사되었다. 바지락의 생식소 발달에 따른 생식주기는 초기활성기 (1-3월), 후기활성기 (2-5월), 완숙기 (4-8월), 부분산란기 (5-10월), 퇴화/비활성기 (8-2월)의 연속적인 단계로 구분할 수 있었다. 폐각근 조직내 총단백질 함량 (%) 변화는 초기 및 후기 활성기인 2월에 최대에 이른다음 완숙기 및 부분활성기인 5월에 최소값을 나타내었다. 반면, 내장낭 조직 내 총단백질 함량 변화는 완숙 및 부분산란기인 6월에 최대에 이른 후 부분산란기인 6월부터 10월까지 점차 감소되는 경향을 보였다. 전반적으로 폐각근 조직과 내장낭 조직 내의 총단백질 함량 변화 사이에는 음 (-) 의 상관관계를 나타내었다 (r = -0.292, P < 0.05). 폐각근 조직 내 총지질 함량 (%) 변화는 비활성기 및 초기활성기인 1월에 최대에 이른 후, 2월에 급격히 감소되었다. 반면, 내장낭 조직 내 총지질 함량 변화는 후기활성기 및 완숙기인 4월에 최대를 나타내었고, 부분산란기인 5-10 월 사이에 점차 감소되는 경향을 보였다. 전반적으로 폐각근 조직과 내장낭 조직 내의 총지질 함량 변화 사이에는 음 (-) 의 상관관계를 보였다 (r = -0.699, p < 0.05). 폐각근 조직내 글리코겐 함량 (%) 변화는 후기활성기 및 완숙기인 5월에 최대에 이른 다음, 부분산란기인 5월부터 10월까지 급격히 감소되었다. 반면, 내장낭 조직 내 글리코겐 함량 변화는 초기 및 후기활성기인 2월에 최대에 이른 다음, 후기활성기인 3월에 급격히 감소되었으며, 그 후 완숙 및 부분산란기인 4월에서 7월까지 점차 증가되는 경향을 보였다. 전반적으로 폐각근 조직과 내장낭 조직 내의 글리코겐 함량 변화 사이에는 상관관계가 없는 것으로 나타났다(r = 0.062, p > 0.05). 상기 언급된 결과들은 바지락의 폐각근 조직 및 내장낭 조직들이 중요한 에너지 저장소이며, 영양 공급 기관임을 알 수 있었으며, 폐각근 조직과 내장낭 조직들의 영양물질 함량 변화는 생식소의 에너지 요구에 따라 변하고 있음을 알 수 있었다.
Reproductive cycle with the gonadal development of Ruditapes philippinarum can be classified into five successive stages by histological observations: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (May to October), and spent/inactive stage (August to February). Changes in total protein contents in the adductor muscle tissues reached the maximum in the early and late active stages (February) and appeared the minimum in the ripe and partially spawned stages (May), while changes in their contents in the visceral mass tissues reached the maximum in the ripe and partially spawned stages (June) and gradually decreased in the partially spawned stage (June to October). On the whole, changes in total protein contents showed a negative correlationship between the adductor muscle and visceral mass tissues (r = -0.292, p < 0.05). Changes in total lipid contents in the adductor muscle tissues reached the maximum in the inactive and early active stages (January) and sharply decreased in the early and late active stages (February), while their contents in the visceral mass tissues reached the maximum in the ripe and partially spawned stages (April) and gradually decreased in the partially spawned stage (to October). On the whole, changes in total lipid contents showed a negative correlationship between the adductor muscle and visceral mass tissues (r = -0.699, p<0.05). Changes in glycogen contents in the adductor muscle tissues reached the maximum in the late active and ripe stages (April) and rapidly decreased in the partially spawned stage (May to October), while their contents in the visceral mass tissues reached the maximum in the early and late active stages (February) and rapidly decreased in the late active stage (March). Thereafter, their levels gradually increased in the ripe and partially spawned stages (April to July). On the whole, changes in glycogen contents appeared no correlationship between the adductor muscle and visceral mass tissues (r = 0.062, p > 0.05). These results indicate that the adductor muscle and visceral mass tissues are an important energy storage and nutrient supply organ in the Manila clams, and the nutrient contents of the adductor muscle and visceral muscle tissues change in response to gonadal energy needs.
아산시에 분포하는 담수산 연체동물상을 파악하기 위하여 1999년 10월부터 2000년 8월까지 101지점에 대하여 조사하였다. 본 조사에서 채집된 담수산 패류는 2 강 5 목 12 과 27 종이었으며 이중 복족류는 3 목 10 과 18 종이었고 이매패류는 2 목 2 과 9 종이었다. 온양천 수계는 19개 지점에서 2 강 5 목 11 과 21 종이 채집되었고 복족류는 3 목 9 과 17 종, 이매패류는 2 목 2 과 4 종이 채집되었다. 이곳 수계에 우점적으로 분포하고 있는 종은 물달팽이, 왼돌이물달팽이, 논우렁이와 주머니알다슬기였다. 곡교천 수계 25개 지점에서 채집된 패류는 2 강 5 목 11 과 20 종이며 복족류는 3 목 9 과 15 종이었고 이매패류는 2 목 2 과 5 종이 채집되었다. 이곳 수계에서 흔히 분포하고 있는 종은 물달팽이, 수정또아리물달팽이, 애기물달팽이, 그리고 논우렁이 순이었다. 삽교호 수계 32개 지점에서 채집된 패류는 2 강 5 목 11 과 26 종이었으며 복족류는 3 목 9 과 17 종이었고 이매패류는 2 목 2 과 9 종이었다. 이곳 수계의 우점종은 물달팽이, 논우렁이, 또아리물달팽이 순이었다. 아산호 수계 25개 지점에서 채집된 패류는 2 강 5 목 12 과 21 종이었으며, 복족류는 3 목 10 과 17 종이었고 이매패류는 2 목 2 과 4 종이었다. 이곳 수계의 우점종은 논우렁이, 애기물달팽이, 물달팽이, 또아리물달팽이 순이었다. 서식환경별로 살펴보면 논에 주로 서식하고 있었던 종은 긴애기물달팽이, 배꼽또아리물달팽이, 왼돌이물달팽이였으며 하천에서는 물달팽이와 왼돌이물달팽이가 그리고 수정또아리물달팽이가 주로 나타났고, 저수지에서는 논우렁이와 물달팽이, 애기물달팽이, 긴애기물달팽이가 나타났다. 또한 호수에서는 논우렁이, 또아리물달팽이, 큰논우렁이, 물달팽이 순으로 나타났다. 대칭이, 작은대칭이, 펄조개는 저질이 니질인 곳에서 주로 서식하고 있었고 귀이빨대칭이는 사니질과 사질에 주로 서식하고 있었다. 특히 삽교호 수계 채집된 귀이빨대칭이는 사니질과 사질의 저질에서 출현하였다.
In order to understand freshwater molluscan fauna in Asan area, a survey was conducted on the watersheds of this area during the period of October 1999 to August 2000. For the purpose of easy overlook of the molluscan fauna in Asan area, present survey was undertaken on a total of 101 sampling sites of 4 major watersheds connected along Onyang River, Gokgyo River, Sapgyo Lake, and Asan Lake. The collected freshwater mollusks were analysed based on the environment of their habitats. The freshwater mollusks collected through out the present survey were 27 species, 12 families, 5 orders, and 2 classes. Of these, gastropods were 18 species, 10 families, 3 orders; and bivalves were 9 species, 2 families, and 2 orders. The dominant gastropods in this area were Radix auricularia coreana, Cipangopaludina chinensis malleata, Hippeutis cantori, Physa acuta, Gyraulus convexiusculus and Austropeplea ollula and the dominant bivalves were Anodonta arcaeformis, Anodonta arcaeformis flavotincta, and Anodonta woodiana. Dominant species in rice fields were Fossaria truncatula, Segmentina hemisphaerula and Physa acuta, dominant species in rivers were Radix auricularia coreana, Physa acuta, and Hippeutis cantori. Dominant species in reservoirs were Cipangopaludina chinensis malleata, Radix auricularia coreana, Austropeplea ollula, and Fossaria truncatula. Dominant species collected in lakes were Cipangopaludina chinensis malleata, Hippeutis cantori, Cipangopaludina japonica, and Radix auricularia coreana. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Austropeplea ollula were dominantly inhabiting on the muddy bottoms. Anodonta woodiana, Cipangopaludina japonica, and Corbicula fluminea occurred mainly in the gravel areas. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Hippeutis cantori were dominant in the muddy rock areas. Rock-dominant species were Radix auricularia coreana, Semisulcospira forticosta and Koreanomelania paucicincta. Sand-dominant species were Physa acuta, Radix auricularia coreana, and Hippeutis cantori. Sand gravel-dominant species were Physa acuta, Radix auricularia coreana, and oreanomelania paucicincta. Hippeutis cantori, Cipangopaludina chinensis malleata, and Gyraulus convexiusculus occurred in the sand-muddy areas. Cristaria plicata, appointed as an endangered species from the "Natural Environmental Conservation Law", was collected from 5 sampling sites (site Nos. 45, 47, 48, and 52). For the endangered species found in this survey should be make appropriate protection.
두족류는 흡반에 의한 흡착력이 강하여 방류시 분리 포획에 어려움이 있는 어린 주꾸미의 마취 소요시간에 따른 효과면에서 200 ppm 이하의 농도에서 염산리도카인이 MS-222보다 1.6-4.5배정도 마취가 빨랐고 300-500 ppm의 농도에서는 5.10-6.0배 빨랐다. 노출시간에 따른 마취율과 회복률에 염산리도카인이 MS-222보다 저농도에서 짧은 시간 내 마취되고 고농도에서 빠른 시간 내에 회복되었다. 1차 마취 후 경과시간별 염산리도카인의 재마취에서 농도가 낮고 경과시간이 길수록 마취개시 및 종료시간이 늦어지고 농도가 높고 경과시간이 짧을수록 마취개시 및 종료시간이 빨라졌다. 재마취 회복 또한 저농도에서 경과시간이 길수록 빠르고 고농도에서 경과시간이 짧을 수록 회복이 늦어졌다. 주꾸미의 경우 MS-222보다는 염산리도카인이 마취에 좋았으며 작업을 고려한 사용농도 및 한계시간은 100 ppm 농도에 15분 이내가 적당하였다. 감사의 글이 논문은 2000년 국립수산진흥원 부안수산종묘시험장의 경상사업으로 수행된 연구 결과의 일부로 이에 감사드립니다.
After the juvenile octopus individuals being discharged, it is hard to separately capture them because they attach strongly to the wall of the aquarium by the suckers on the arms. Therefore, anaesthetics (MS-222 or lidocaine-HCl) are usually used for capture from attachment. The anaesthetized time of the octopus by lidocaine-HCl was more faster 1.6 to 4.5 times under 200 ppm and 6.0 to 6.5 times in 300 to 500 ppm than those in MS-222. In the anaesthetized and recovery rates (%) by the exposed time, the juvenile octopuses were anesthetized by lower concentrations of lidocaine-HCl within the short time, and rapidly recovered from anesthesia. In the secondary anesthesia of the juvenile octopuses exposed with lidocaine-HCl by the elapsed time after the primary anesthesia, the anesthetized time was later in case of lower concentrations and long elapsed times, However, the anesthetized time was faster when their concentrations were higher and the elapsed time after anesthesia were shorter. Recovery from the secondary anesthesia was faster when the elapsed time was long in lower concentration, and was later when the elapsed time was shorter. In case of Octopus ocellatus, anaesthetic effects by lidocaine- HCl concentrations were better than those of MS-222. Doses of lidocaine-HCl and critical time for works at the indoor laboratory were proper in concentration of 100 ppm within 15 min.
