굴 Crassostrea gigas 유생 성장단계별 미세조류 12의 소화도 = Digestion indices of 12 species of microalgae by the oyster Crassostrea gigas larval development stages

다국어 초록 (Multilingual Abstract)

Twelve species of food microalgae were investigated to clarify the digestion index of Crassostrea gigas larvae using epifluorescence microscopy to choose an appropriate diet for artificial seed production in hatchery. An experiment was conducted using 1 (D shaped stage), 4 (Early umbo stage), 8 (umbo stage) and 12 (Full grown stage) days old larvae. larvae were stocked in 1 L flasks at 5 individuals/mL and fed 10×104 algal cells/mL of each species individually. Prior to larvae were fed for 3 h and then were observed under the microscope to detect ingestion; larvae were then sieved and replaced in 1 L flasks containing filtered seawater and were observed after 3, 5 and 8 h to analyse the digestion index. Values of digestion indices were specific for each alga. No evidence for the ingestion of Thalassiosira weissflogii was evident at all larval development stages tested. Digestion indices of others microalgae were 0.8-99.7% at 4 stage of larval development stages: Chlorella ellipsoidea (0.8-5.4%), Nannochloris oculata (1.4-5.0%), Isochrysis galbana (99.1-99.5%), Pavlova lutheri (99.1-99.5%), I. aff. galbana (99.4-99.5%), Cheatoceros calcitrans (0.0-99.2%), C. gracilis (0.0-99.7%), C. simplex (0.0-95.9%), Phaeodactylum tricornutum (0.0-99.6%), Tetraselmis tetrathele (0.0-99.7%) and Dunaliella tertiolecta (0.0-99.6%), respectively. Therefore, it is assumed that food microalgae showing the high digestion such as I. galbana should be supplied to the early umbo stage larvae, and then after the umbo larval stage, the mixed microalgae with diatoms and light green algae should be supplied to the full grown stage larvae to increase the digestion of their larvae.

국문 초록 (Abstract)

굴 인공종묘생산 시 적정 먹이생물을 선택하기 위하여 먹이생물로 이용되고 있는 12종의 미세조류를 대상으로 굴 유생의소화도를 조사하였다. 조사는 유생의 발달단계에 따라 D형 유생, 초기각정기 유생, 각정기 유생 및 부착기 유생으로 구분하여 수용적 1L 수조에 5 마리/mL 밀도로 각각의 성장단계별유생을 수용하고, 조사대상 먹이생물 12종을 각각 투여하였다.
소화도 측정은 먼저 12종의 먹이생물을 공급 후 3시간 동안충분히 섭취하도록 방치한 후 먹이섭취 상태를 현광현미경으로 확인하였다. 이 후 유생은 걸름망으로 걸러 여과해수가 채워진 비이커에 재 수용 후 3,5 및 8시간 후 소화도를 현광현미경으로 측정하였다. 12종 미세조류의 소화도는 유생의 발달단계에 따라 다양했다. 전 유생기 동안 Thalassiosira weissflogii는 섭취가 관찰되지 않았고, 나머지 종의 소화도는유생의 발달단계에 따라 0.8-99.7%: Chlorella ellipsoidea (0.8-5.4%), Nannochloris oculata (1.4-5.0%), Isochrysis galbana (99.1-99.5%), Pavlova lutheri (99.1-99.5%), I.
aff. galbana (99.4-99.5%), Cheatoceros calcitrans (0.0-99.2%), C. gracilis (0.0-99.7%), C. simplex (0.0-95.9%), Phaeodactylum tricornutum (0.0-99.6%),Tetraselmis tetrathele (0.0-99.7%) 그리고 Dunaliella tertiolecta (0.0-99.6%)로 나타났다. 따라서 초기 유생은 I.
galbana와 같이 소화성이 높은 것을 공급하고 각정기 이후규조류 또는 담녹조류를 혼합해 주는 것이 소화성을 높일 수있을 것으로 판단된다.

참고문헌 (Reference)

1 Gallager, S.M., "Visual observations of particle manipulation during feeding in larvae of a bivalve mollusk" 43 : 344-365, 1988

2 Coutteau, P., "The use of algal substitutes and the requirement for live algae in hatchery and nursery rearing of bivalve molluscs: An international survey" 11 : 467-476, 1992

3 Myers, J.A., "The economics of producing algae and bivalve seed in hatcheries" 86 : 163-179, 1990

4 Lemos, M.B.N., "The combined effects of salinity, temperature, antibiotics and aeration on larval growth and survival of the mangrove oyster, Crassostrea rhizophorae" 13 : 187-192, 1994

5 Ben-Amotz, A., "The biotechnology of cultivating the halotolerant alga Dunaliella. in: Trends in Biotechnology" lenum Press 121-126, 1980

6 Gerdes, D., "The Pacific oyster Crassostrea gigas. Part I. Feeding behavior of larvae and adults" 31 : 195-219, 1983

7 Robert, R., "Substitutes for live microalgae in mariculture: a review" 10 : 315-327, 1997

8 Devakie, M.N., "Salinity-temperature and nutritional effects on the setting rate of larvae of the tropical oyster, Crassostrea iredalei (Faustino)" 184 : 105-114, 2000

9 Urban, E.R., "Reduction in costs of diets for the American oyster, Crassostrea virginica (Gmelin), by the use of non-algal supplements" 38 : 277-291, 1984

10 Webb, K.L., "Phytoplankton as a food source for bibalve larvae. in: Second International Conference on Aquaculture Nutrition: Biochemical and Physiological Approaches to Shellfish Nutrition" Louisiana State University 272-291, 1982

11 Bayne, B.L., "Physiological ecology of marine molluscan larvae. in: The Mollusca, vol. III" Academic Press 299-343, 1983

12 Aldana-Aranda, D., "Observations on ingestion and digestion of unicellular algae by Strombus gigas larvae (Mollusca, Gastropoda) using epifluorescence microscopy" 92 : 359-366, 1991

13 Albentosa, M., "Nutritional value of algal diets to clam spat Venerupis pullastra" 97 : 261-269, 1993

14 Ponis, E., "Nutritional value of Pavlova lutheri, Isochrysis aff. galbana clone T-Iso and Chaetoceros calcitrans forma pumilum, either fresh or preserved, for larval and post-larval development of Pacific oyster (Crassostrea gigas)" 221 : 491-505, 2003

15 Aldana-Aranda, D., "Nutritional potentialities of Chlamydomonas coccoides and Thalassiosira fluviatilis, as measured by their ingestion and digestion rates by the Queen Conch larvae (Strombus gigas)" 156 : 9-20, 1997

16 Aldana-Aranda, D., "Ingestion and digestion of eight algae by Strombus gigas larvae (Mollusca, Gastropoda) Studied by epifluorescence microscopy" 126 : 151-158, 1994

17 Rico-Villa, B., "Influence of phytoplankton diet mixtures on microalgae consumption, larval development and settlement of the Pacific oyster Crassostrea gigas (Thunberg)" 256 : 377-388, 2006

18 Rico-Villa, R., "Influence of food density and temperature on ingestion, growth and settlement of Pacific oyster larvae, Crassostrea gigas" 287 : 395-401, 2009

19 Albentosa, M., "Growth performance and biochemical composition of Ruditapes decussatus (L.) spat fed on microalgal and wheatgerm flour diets" 232 : 23-37, 1999

20 Elston, R., "Functional morphology of the coelomocytes of the larval oysters (Crassostrea virginica and Crassostrea gigas)" 60 : 947-957, 1980

21 Elston, R., "Functional anatomy, histology and ultrastructure of the soft tissues of the larval American oyster, Crassostrea virginica" 65-93, 1980

22 Floyd, D.J., "Foods and feeding of oysters as observed with the use of radioactive plankton" 71-180, 1953

23 Baldwin, B.S., "Feeding rate responses of oyster larvae (Crassostrea virginica) to seston quantity and composition" 189 : 77-91, 1995

24 Owen, G., "Feeding and digestion in the bivalvia. in: Advances in Comparative Physiology and Biochemistry, vol. 5" Academic Press 1-35, 1974

25 Walne, P.R., "Factors affecting the relation between feeding and growth in bivalves. in: Harvesting Polluted Waters" Plenum Press 169-183, 1976

26 Helm, M.M., "Experiments in the hatchery of Pacific oyster (Crassostrea gigas Thunberg)" 11 : 1-12, 1977

27 Wisely, B., "Experimental feeding of sydney rock oysters (Carssostrea commercialis = Saccostrea cucullata): Ⅰ. optimum particle sizes and concentrations" 15 : 319-331, 1978

28 Enes, P., "Evaluation of microalgae and industrial cheese whey as diets for Tapes decussatus (L.) seed: effect on water quality, growth, survival, condition and filtration rate" 34 : 299-309, 2003

29 Babinchak, J., "Epifluorescence microscopy, a technique for the study of feeding in Crassostrea virgtnica veliger larvae" 51 : 69-76, 1979

30 Abdel-Hamid, M.E., "Effects of temperature, food and food concentrations on the growth of the larvae and spat of the edible oyster Crassostrea gigas (Thunberg)" 34 : 195-202, 1992

31 Lucas, A., "Detection of the first larval feeding in Crassostrea gigas, using epifluorescence microscope" 30 : 366-374, 1983

32 Walne, P.R., "Culture of bivalve molluscs, 173" The whitefriars Press Ltd 1974

33 Badillo-Salas, C.E., "Comparative growth of Pacific oyster (Crassostrea gigas) postlarvae with microfeed and microalgal diets" 17 : 173-186, 2009

34 Espinosa, E.P., "Comparative growth and survival of juvenile hard clams, Mercenaria mercenaria, fed commercially available diets" 25 : 503-525, 2006

35 His, E., "Combined effects of temperature and salinity on fed and starved larvae of the Mediterranean mussel, Mytilus galloprovincialis and the Japanese oyster Crassostrea gigas" 100 : 455-463, 1989

36 Dunstan, G.A., "Biochemical composition of microalgae from the green algal classes Chlorophyceae and Prasinophyceae. 2. Lipid classes and fatty acids" 161 : 115-134, 1992

37 Ponis, E., "Assessment of the performance of Pacific oyster (Crassostrea gigas) larvae fed with fresh and preserved Pavlova lutheri concentrates" 11 : 69-79, 2003

38 Ewart, J.W., "A tropical flagellate food for larval and juvenile oysters, Crassostrea virginica Gmelin" 22 : 297-300, 1981