1. (Gastropoda), (Prosobranchia), (Mesogastropoda), (Pleuroceridae),,,. 3 7,.,,.,,.,.. (Habe and Itagaki, 1978), (Nakano and Nishiwaki, 1989), (Koike et al., 1992), (Nakano and Izawa, 1996). (S. forticosta) (Kil, 1977), (Im et al., 1986), (Kim et al., 1985) (Kim et al., 1987). 1).

Turbo cornutus (Lee, 1980), Anodonta (Sinanodonta) woodiana (Chung, 1980), Fulvia mutica (Chang and Lee, 1982), Solen strictus (Chung et al, 1986), Ruditapes philippinarum (Chung et al., 1994), Patinopecten yessoensis (Chang et al., 1985; Chang et al., 1997), Tresus keenae (Kim et al., 1999), (Kang, 1986),.,. 2. 2.1..,,,. 2.,,,.,, 5. 2.2. (S. gottschei) 4 184.3±56.1 5 350.0±127.6, 9 132.4±65.2. 10, 11 300, 12 113.4±50.5 (Fig. 1). 4, 0 150 2, 3 10%, 4 25.7% 5. 9 60.3%, 10, 11. 150 300 2 75%, 6. 7 50%, 10. 300 450 5 6, 7. 450 600 3 5, 10, 11, 12 2, 9.

AVERAGE OOCYTE DIAMETER ( μm ) 500 400 300 200 100 0 Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. MONTH 2.3., (Fig. 2 3). Trochophore Pre-veliger 0.2 mm Veliger Juvenile

2400 LARVAE NUMBER/SNAIL 2000 1600 1200 800 400 n=8 n=13 n=13 n=7 n=8 n=11 n=7 n=7 n=11 n=12 n=5 n=10 0 Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. MONTH trochophore 1 1.2%, 5 65.2%. 8 6%, 10 38.4% 12 3.2%. Pre-veliger 1 2.3% 6 27.6% 8 7.2%. 10 24.0%, trochophore 12. Veliger 4 32.7% 5 10.4% 6 12. Juvenile 1 82.4%, 5 1.4%. 8 64.2%, 9, 10 11, 12. juvenile trochophore 5 10, 2. 2.4., 2, 2 9, 3 10, 4, 5 11, 6, 7 12, 8 1, 2 8, 3, 4 9, 5 10, 11, 6 12, 7 1.

, 2. 3. 3.1. 30 29.51 mm 13.19 mm 2.32 g. 3.2. 30, 60, 90 120 500 Bottle 1, Fig. 4.. 3.3. 105 243 245 187 ( 2, Fig. 5). 3.4. + 60 122 ( 3-4, Fig. 6). UV. 18 22 12. 1 300 500.

1. * Time to parturition ** Number of new born juvenile

2. UV * Time to parturition ** Number of new born juvenile

3. + ( : 60 ) * Time to parturition ** Number of new born juvenile

4. + ( : 30 ) * Time to parturition ** Number of new born juvenile

300 120 Mean time to parturition 250 200 150 100 50 Mean time to parturition Mean number of juvenile 100 80 60 40 20 Mean number of juvenile 0 0 CON 30 60 90 120 Duration of air exposure (min) Fig. 4. Mean time to parturition and number of juvenile of freshwater snail, Semisulcospira gottschei by air exposure. Mean time to parturition 300 250 200 150 100 50 Mean time to parturition Mean number of juvenile 250 200 150 100 50 Mean number of juvenile 0 0 CON 3 6 9 Increasing of water temperature Fig. 5. Mean time to parturition and number of juvenile of freshwater snail, Semisulcospira gottschei by increasing water temperature.

70 140 Mean time to parturition 60 50 40 30 20 10 Mean time to parturition Mean number of juvenile 120 100 80 60 40 20 Mean number of juvenile 0 CON 60 min+3 Up 60 min+6 Up 60 min+9 Up 0 Air exposure (60 min) + Increasing of water temperature Fig. 6. Mean time and number of parturition of freshwater snail, Semisulcospira gottschei by increasing water temperature and air exposure (60 min). Chang, Y.J. and T.Y. Lee. 1982. Gametogenesis and reproductive cycle of the cockle, Fulvia mutica (Reeve). Bull. Korean Fish. Soc., 15, 241-253. Chang, Y.J., H.K. Lim and Y.J. Park. 1997. Reproductive cycle of the cultured scallop, Patinopecten yessoensis in eastern waters of Korea. J. Aquaculture, 10(2), 133-141. (in Korean) Chang, Y.J., K. Mori and T. Nomura. 1985. Studies on the scallop, Patinopecten yessoensis, in sowing cultures in Abashiri waters -Reproductive periodicity. Tohoku J. Agr. Res., 35, 91-104. Chung, E.Y. 1980. Reproductive cycle and breeding season of the freshwater clam, Anodonta (Sinanodonta) woodiana (Lea). Bull. Korean Fish. Soc., 13, 135-144. (in Korean) Chung, E.Y., H.B. Kim and T.Y. Lee. 1986. Annual reproductive cycle of the jackknife clams, Solen strictus and Solen gordonis. Bull. Korean Fish. Soc., 19, 563-574. (in Korean) Chung, E.Y., D.K. Ryou and J.H. Lee. 1994. Gonadal development, age and growth of

the shortnecked clam, Ruditapes philippinarum (Pelecypoda; Veneridae), on the coast of Kimje, Korea. Korean J. Malacol., 10, 38-54. Habe, S. and H. Itagaki. 1978. Ecological study on the freshwater snail Semisulcospira libertina (Gould, 1959). Jap. J. Malac. (Venus)., 37, 77-82. Im, S.K., I.S. Joung, P.R. Chung and K.T. Lee. 1986. Residual chlorinated hydrocarbon pesticides in Semisulcospira spp. (Gastropoda: Pleuroceridae) collected at the endemic and non-endemic areas of paragonimiasis in Korea. Korean J. Malacol. 2(1), 13-25. (In Korean) Koike, K., S. Kuniyoshi, K. Furuse, N. Umezawa, A. Masuda and S. Nishiwaki. 1992. Seasonal changes in gametogenesis and embryo composition in the brood pouch of Semisulcospira libertina. Venus, 51, 279-294. (in Japanese) Kil, B.S. 1977. Ecological studies on the freshwater gastropodas in Korea. Distribution of Semisulcospira forticosta in the Taebaek range. Korea. J. Limnol., 10, 29-35. (in Korean) Kim, Y.H., T.K. Lee and Y.S. Cha. 1985. Studies on the nutritive component of black snail, Semisulcospira libertina. Collection of Thesis, Chonbuk Nat. Uni., 16, 101-105. (in Korean) Kim, D.H., H.K. Lim, K.S. Min, Y.J. Chang and T.I. Kim. 1999. Reproductive cycle of surf clam (Tresus keenae) in southern coast of Korea. J. Korean Fish. Soc., 32, 659-663. (in Korean) Lee, J.H. 1980. Gametogenesis and reproductive cycle of the topshell, Turbo cornutus Solander. Bull. Korean Fish. Soc., 13, 125-134. (in Korean) Nakano, D. and K. Izawa. 1996. Reproductive biology of Semisulcospira libertina (Prosobranchia: Pleuroceridae) in Iga Basin, Mie Prefecture. Venus, 55, 235-241. Nakano, D. and S. Nishiwaki. 1989. Anatomical and histological studies on the reproductive system of Semisulcospira libertina (Prosobranchia: Pleuroceridae). Venus, 48, 263-273.

표 1. 다슬기수입량 : 연도별 2000년 2001년 2002년 2003년10월 냉동다슬기 3.4 79.88 92 151.5 냉동 ( 자숙 ) 8.09 272 2.46 25.71 냉동 ( 참다슬기 ) 3.75 냉동 ( 참. 자숙 ) 3.92 냉동살 ( 자숙 ) 149.21 458.85 641.27 냉동살 ( 참다슬기 ) 3.26 냉동살 ( 참. 자숙 ) 47.69 냉장다슬기 5 활다슬기 54.47 97.72 활 ( 참다슬기 ) 21.46 2.11 15.7 합계 165.7 377.09 613.15 983.51 표 2. 다슬기수입량 국가별 2000년 2001년 2002년 2003년10월 중국 ( 냉동다슬기 ) 3.4 79.88 92 151.5 중국 ( 냉동-자숙 ) 8.09 2.46 25.71 중국 ( 냉동살-자숙 ) 149.21 272 448.69 550.4 중국 ( 냉장다슬기 ) 5 중국 ( 냉동-참다슬기 ) 3.75 중국 ( 활다슬기-참 ) 21.46 2.11 중국 ( 냉동살-참, 자숙 ) 3.26 중국 ( 활다슬기 ) 40.26 65.34 합계 165.7 377.09 588.78 792.95 북한 ( 냉동살-자숙 ) 7.14 88.87 북한 ( 냉동-참다슬기 ) 17.74 북한 ( 참다슬기, 자숙 ) 3.92 북한 ( 다슬기살-참, 자숙 ) 47.69 북한 ( 활다슬기 ) 16.62 북한 ( 활다슬기-참다슬기 ) 15.7 합계 7.14 190.54 일본 ( 냉동살-자숙 ) 7.14 2 일본 ( 활다슬기 ) 14.21 15.76 일본 ( 냉동살-자숙 ) 합계 21.35 17.76

곳체 - 다슬기성장비교 곳체 - 참다슬기성장비교 7 6 곳체 참다슬기 8 7 곳체 참다슬기 5 6 각고 (mm) 4 3 2 각고 (mm) 5 4 3 2 1 1 0 4/1 4/11 4/21 5/1 5/11 5/21 5/31 6/10 6/20 6/30 7/10 사육일 0 5/8 5/18 5/28 6/7 6/17 6/27 7/7 7/17 7/27 8/6 사육일

n-3 HUFA

α α

α

Flake Pellet Powder Mean weight gain (mg/snail) 100 bc a ab cd cd bc bc d cd 0 1 2 3 Diets