나팔고둥 Charonia sauliae의 자원회복 및 방류종패의 생산을 위한 번식생물학적 연구 Study on reproductive biology for resources restoration and seedling production of trumpet shell Charonia sauliae원문보기
나팔고둥은 환경부 지정 멸종위기종 1급 생물로서 그 분포역이 동해남부 및 제주도를 포함한 남해안 일대 해역인 것으로 알려져 있으나, 현재는 제주도 연안에만 서식하는 것으로 밝혀져 자연자원의 회복이 시급한 과제로 등장하고 있다. 본 연구에서는 나팔고둥의 자원회복 및 양식을 위한 종묘생산 기초기술의 개발을 목적으로 채포금지 구역에서의 분포환경 및 혼획상황, 모패의 확보방법, 암수의 성숙 및 교미행동에 이은 난낭의 출산 등 번식생태를 구명하고, 수정란의 부화 및 유생과 치패의 사육 등 종묘생산에 관한 기반실험을 실시하였다.
1. 번식생태 나팔고둥 암컷과 수컷의 성비는 1.78ː1이었고 220~260 mm의 각고 범위에 있는 개체들은 암컷인데 반하여(79.5%), 수컷의 88.2%는 180~220 mm 범위였다. 이러한 연구 결과로 나팔고둥의 암컷이 수컷보다 각고의 길이가 더 큰 경향이 있는 것으로 판단된다. 나팔고둥의 성장은 암컷 나팔고둥을 제외하고는 서로 다른 먹이 종류에 큰 영향을 받지 않았다. 나팔고둥의 섭취 비율은 먹이 종류에 따라 크게 영향을 받았고, ...
나팔고둥은 환경부 지정 멸종위기종 1급 생물로서 그 분포역이 동해남부 및 제주도를 포함한 남해안 일대 해역인 것으로 알려져 있으나, 현재는 제주도 연안에만 서식하는 것으로 밝혀져 자연자원의 회복이 시급한 과제로 등장하고 있다. 본 연구에서는 나팔고둥의 자원회복 및 양식을 위한 종묘생산 기초기술의 개발을 목적으로 채포금지 구역에서의 분포환경 및 혼획상황, 모패의 확보방법, 암수의 성숙 및 교미행동에 이은 난낭의 출산 등 번식생태를 구명하고, 수정란의 부화 및 유생과 치패의 사육 등 종묘생산에 관한 기반실험을 실시하였다.
1. 번식생태 나팔고둥 암컷과 수컷의 성비는 1.78ː1이었고 220~260 mm의 각고 범위에 있는 개체들은 암컷인데 반하여(79.5%), 수컷의 88.2%는 180~220 mm 범위였다. 이러한 연구 결과로 나팔고둥의 암컷이 수컷보다 각고의 길이가 더 큰 경향이 있는 것으로 판단된다. 나팔고둥의 성장은 암컷 나팔고둥을 제외하고는 서로 다른 먹이 종류에 큰 영향을 받지 않았다. 나팔고둥의 섭취 비율은 먹이 종류에 따라 크게 영향을 받았고, 아무르불가사리 Asteras amurensis를 포식한 실험구의 섭취 비율은 별불가사리 Asterina pectinifera를 먹은 실험구보다 높게 나타났다. 또한 나팔고둥의 섭취 비율의 변이성은 실험 기간 동안 수온의 변화와 일치하였다. 별불가사리 Asterina pectinifera단독 공급구와 별불가사리 Asterina pectinifera와 아무르불가사리 Asteras amurensis 혼합 공급구의 난낭 산출이 각각 393개의 난낭과 134개의 난낭을 가지는데 반해서 아무르불가사리 Asteras amurensis를 먹은 실험구에서는 493개의 난낭을 부착하였다. 불가사리의 종류별로 먹이를 공급한 실험구에서 나팔고둥 유생의 개체 크기, 성장률과 유생의 부화율은 실험구에 따른 뚜렷한 차이는 없었으나, 유생의 생존율 경우는 불가사리 종류에 따른 영향을 받는 것으로 조사되었다. 아무르불가사리 Asteras amurensis로 사육된 구간에서 생산된 유생의 생존율은 2종의 불가사리 혼합 공급구와 별불가사리 Asterina pectinifera을 단독 공급한 실험구 보다 더 높았으며 15°C 실험구에서 부화된 유생은 20°C 실험구에서 부화된 유생의 생존율과 부화율과 비교했을 때, 높은 생존율과 부화율을 나타냈다. 난낭내 수정란은 사육 수온이 높을수록 부화 시간이 짧게 나타났으나 부화율은 낮아지는 경향이었다. 나팔고둥 수정란의 최대 부화율을 보이는 수온은 18.8°C로 나타났으며, 부화율은 94%였다. 나팔고둥은 교미 기간 동안 precopulatory mounting을 지니고 암컷 개체들은 외투강을 사용하여 부화된 알을 보호하였다. 나팔고둥은 일반적인 세포분열을 통하여 상실기, 포배기, 낭배기, 담륜자기, veliger 및 치패로 성장하는 난발생 및 유생단계를 가지고 있으며, 같은 속에 속해 있는 다른 해양 고둥류와 비교할 때 분명한 담륜자기 단계를 관찰할 수 있었고 난낭으로부터 부화된 후에도 충분한 난황을 여전히 보존하였다. 이러한 결과는 자연상태의 조건하에서 나팔고둥 어미를 제거하지 않는다고 할 경우, 유생의 생존 기회를 더욱 높일 수 있는 나팔고둥 어미만의 특유한 모성본능이라고 판단된다.
2. 종묘생산 나팔고둥의 유생 및 치패의 발생 특징, 성장 및 생존율에 미치는 수온의 영향을 수온 10°C, 15°C, 20°C, 25°C 및 30°C의 실험구에서 실시하였다. 본 실험 결과, 나팔고둥 유생 및 치패의 성장률은 수온 변화에 따fms 영향을 받는 것으로 나타났다. 유생 단계의 지속 시간은 수온과 역상관 관계를 나타내었으며, 수온은 후기유생 크기, 유생과 치패의 생존율에 관하여 영향을 미치는 것으로 나타났다. 최대 유생의 크기, 생존율 및 치패 생존율을 나타내는 수온은 각각 22.6°C, 19.8°C, 19.4°C로 조사되었다. 본 연구 결과 수온은 나팔고둥 유생과 치패의 발생, 성장 그리고 생존에 영향을 끼치는 주요 요인이라는 것을 알 수 있었으며, 나팔고둥의 최적 성장 수온은 19~23°C의 범위로 조사되었다. 유생 사육 실험에서는 먹이생물 6종(Pavlova lutheri, Tetraselmis suecica, Nannochloris oculata, Isochrysis galbana, Chaetoceros calcitrans, Phaeodactylum tricornutum)을 사용하였으며 유생과 치패의 성장 및 생존율 실험은 먹이생물 3종(T. suecica, C. calcitrans, P. tricornutum)을 사용하였다. 본 실험 결과, veliger 유생의 소화지수는 서로 다른 먹이생물 종에 따라 상당한 차이가 나타나는 것을 알 수 있었고, 유생 사육시 더 적합한 것은 T. suecica, C. calcitrans, P. tricornutum 이었다. 해양 미세조류 먹이 종류에 따른 나팔고둥 유생과 치패의 성장 및 생존에 관한 많은 영향을 끼쳤으며, P. tricornutum을 먹이로 사용했을 때 가장 효과가 좋은 것으로 나타났다. 유생 크기는 난낭에서 부화된 초기유생의 각장은 350 µm, 각폭은 210 µm이었으며 변태기에 들어가기 시작했을 때의 유생 각장은 약 550 µm, 각폭 350 µm에 달하였다. 유생의 최대 성장률은 변태기 동안 나타났으며 각폭, 개구면, 나탑의 길이와 각고와의 관계는 선형적이었다. 한편 성장률은 각폭> 개구면> 나탑의 순이었다. 또한 각폭에 대한 각고 비율, 개구면에 대한 각고의 비율 그리고 나탑과 각고의 비율은 각고가 증가함에 따라 실질적인 상관관계가 있는 것으로 나타났다. 시간 경과에 따른 먹이생물의 밀도는 모든 실험구에서 점차적으로 감소하였다. 가장 크게 감소한 실험구는 수온 20°C와 염분 33 psu 구이었으며 이러한 원인으로는 수온 20°C와 염분 33 psu의 환경적 인자 값이 유생의 먹이 활동에 더욱 적합하였던 것으로 판단된다. 수온 5°C, 10°C, 25°C에서 사육된 유생의 운동성은 각각 4, 5, 7시간 후에 감소하기 시작하였으나, 15°C와 20°C 범위의 나팔고둥 유생은 더욱 활발한 운동성을 나타냈다.
나팔고둥은 환경부 지정 멸종위기종 1급 생물로서 그 분포역이 동해남부 및 제주도를 포함한 남해안 일대 해역인 것으로 알려져 있으나, 현재는 제주도 연안에만 서식하는 것으로 밝혀져 자연자원의 회복이 시급한 과제로 등장하고 있다. 본 연구에서는 나팔고둥의 자원회복 및 양식을 위한 종묘생산 기초기술의 개발을 목적으로 채포금지 구역에서의 분포환경 및 혼획상황, 모패의 확보방법, 암수의 성숙 및 교미행동에 이은 난낭의 출산 등 번식생태를 구명하고, 수정란의 부화 및 유생과 치패의 사육 등 종묘생산에 관한 기반실험을 실시하였다.
1. 번식생태 나팔고둥 암컷과 수컷의 성비는 1.78ː1이었고 220~260 mm의 각고 범위에 있는 개체들은 암컷인데 반하여(79.5%), 수컷의 88.2%는 180~220 mm 범위였다. 이러한 연구 결과로 나팔고둥의 암컷이 수컷보다 각고의 길이가 더 큰 경향이 있는 것으로 판단된다. 나팔고둥의 성장은 암컷 나팔고둥을 제외하고는 서로 다른 먹이 종류에 큰 영향을 받지 않았다. 나팔고둥의 섭취 비율은 먹이 종류에 따라 크게 영향을 받았고, 아무르불가사리 Asteras amurensis를 포식한 실험구의 섭취 비율은 별불가사리 Asterina pectinifera를 먹은 실험구보다 높게 나타났다. 또한 나팔고둥의 섭취 비율의 변이성은 실험 기간 동안 수온의 변화와 일치하였다. 별불가사리 Asterina pectinifera단독 공급구와 별불가사리 Asterina pectinifera와 아무르불가사리 Asteras amurensis 혼합 공급구의 난낭 산출이 각각 393개의 난낭과 134개의 난낭을 가지는데 반해서 아무르불가사리 Asteras amurensis를 먹은 실험구에서는 493개의 난낭을 부착하였다. 불가사리의 종류별로 먹이를 공급한 실험구에서 나팔고둥 유생의 개체 크기, 성장률과 유생의 부화율은 실험구에 따른 뚜렷한 차이는 없었으나, 유생의 생존율 경우는 불가사리 종류에 따른 영향을 받는 것으로 조사되었다. 아무르불가사리 Asteras amurensis로 사육된 구간에서 생산된 유생의 생존율은 2종의 불가사리 혼합 공급구와 별불가사리 Asterina pectinifera을 단독 공급한 실험구 보다 더 높았으며 15°C 실험구에서 부화된 유생은 20°C 실험구에서 부화된 유생의 생존율과 부화율과 비교했을 때, 높은 생존율과 부화율을 나타냈다. 난낭내 수정란은 사육 수온이 높을수록 부화 시간이 짧게 나타났으나 부화율은 낮아지는 경향이었다. 나팔고둥 수정란의 최대 부화율을 보이는 수온은 18.8°C로 나타났으며, 부화율은 94%였다. 나팔고둥은 교미 기간 동안 precopulatory mounting을 지니고 암컷 개체들은 외투강을 사용하여 부화된 알을 보호하였다. 나팔고둥은 일반적인 세포분열을 통하여 상실기, 포배기, 낭배기, 담륜자기, veliger 및 치패로 성장하는 난발생 및 유생단계를 가지고 있으며, 같은 속에 속해 있는 다른 해양 고둥류와 비교할 때 분명한 담륜자기 단계를 관찰할 수 있었고 난낭으로부터 부화된 후에도 충분한 난황을 여전히 보존하였다. 이러한 결과는 자연상태의 조건하에서 나팔고둥 어미를 제거하지 않는다고 할 경우, 유생의 생존 기회를 더욱 높일 수 있는 나팔고둥 어미만의 특유한 모성본능이라고 판단된다.
2. 종묘생산 나팔고둥의 유생 및 치패의 발생 특징, 성장 및 생존율에 미치는 수온의 영향을 수온 10°C, 15°C, 20°C, 25°C 및 30°C의 실험구에서 실시하였다. 본 실험 결과, 나팔고둥 유생 및 치패의 성장률은 수온 변화에 따fms 영향을 받는 것으로 나타났다. 유생 단계의 지속 시간은 수온과 역상관 관계를 나타내었으며, 수온은 후기유생 크기, 유생과 치패의 생존율에 관하여 영향을 미치는 것으로 나타났다. 최대 유생의 크기, 생존율 및 치패 생존율을 나타내는 수온은 각각 22.6°C, 19.8°C, 19.4°C로 조사되었다. 본 연구 결과 수온은 나팔고둥 유생과 치패의 발생, 성장 그리고 생존에 영향을 끼치는 주요 요인이라는 것을 알 수 있었으며, 나팔고둥의 최적 성장 수온은 19~23°C의 범위로 조사되었다. 유생 사육 실험에서는 먹이생물 6종(Pavlova lutheri, Tetraselmis suecica, Nannochloris oculata, Isochrysis galbana, Chaetoceros calcitrans, Phaeodactylum tricornutum)을 사용하였으며 유생과 치패의 성장 및 생존율 실험은 먹이생물 3종(T. suecica, C. calcitrans, P. tricornutum)을 사용하였다. 본 실험 결과, veliger 유생의 소화지수는 서로 다른 먹이생물 종에 따라 상당한 차이가 나타나는 것을 알 수 있었고, 유생 사육시 더 적합한 것은 T. suecica, C. calcitrans, P. tricornutum 이었다. 해양 미세조류 먹이 종류에 따른 나팔고둥 유생과 치패의 성장 및 생존에 관한 많은 영향을 끼쳤으며, P. tricornutum을 먹이로 사용했을 때 가장 효과가 좋은 것으로 나타났다. 유생 크기는 난낭에서 부화된 초기유생의 각장은 350 µm, 각폭은 210 µm이었으며 변태기에 들어가기 시작했을 때의 유생 각장은 약 550 µm, 각폭 350 µm에 달하였다. 유생의 최대 성장률은 변태기 동안 나타났으며 각폭, 개구면, 나탑의 길이와 각고와의 관계는 선형적이었다. 한편 성장률은 각폭> 개구면> 나탑의 순이었다. 또한 각폭에 대한 각고 비율, 개구면에 대한 각고의 비율 그리고 나탑과 각고의 비율은 각고가 증가함에 따라 실질적인 상관관계가 있는 것으로 나타났다. 시간 경과에 따른 먹이생물의 밀도는 모든 실험구에서 점차적으로 감소하였다. 가장 크게 감소한 실험구는 수온 20°C와 염분 33 psu 구이었으며 이러한 원인으로는 수온 20°C와 염분 33 psu의 환경적 인자 값이 유생의 먹이 활동에 더욱 적합하였던 것으로 판단된다. 수온 5°C, 10°C, 25°C에서 사육된 유생의 운동성은 각각 4, 5, 7시간 후에 감소하기 시작하였으나, 15°C와 20°C 범위의 나팔고둥 유생은 더욱 활발한 운동성을 나타냈다.
The trumpet shell Charonia sauliae, belonging to Cymatiidae family (Gastropoda), is very rare and valuable marine mollusk species. This large marine snail (shell length may reach 50 cm) had been used by people for centuries as a kind of food and its shell served to jewellery and trum...
The trumpet shell Charonia sauliae, belonging to Cymatiidae family (Gastropoda), is very rare and valuable marine mollusk species. This large marine snail (shell length may reach 50 cm) had been used by people for centuries as a kind of food and its shell served to jewellery and trumpet making. Its shells has been sought after by shell collectors which has led to decrease of Charonia sauliae number. Charonia sauliae natural habitats are distributed in tropical and semi-tropical areas of all three oceans, and were noted at the sea shore of the Red Sea, pacific regions of Africa and Madagascar, and the islands of Pacific in the Atlantic Ocean this species individual was catched at sea coast of Southern Europe. This species inhabits bottom zone of the coral reefs at the depth 20~50 m, but it also was found in deeper sea bottom areas, at the depth 200~300 m. The trumpet shell is animal of prey and its food are mainly starfish species Then the trumpet shell plays an important rolein the reef community. Because of fact that starfish are a kind of harmful organisms which threaten many aquatic economically valuable animals, use of Charonia sauliae for control starfish population appears a good solution for supporting mariculture. A real problem now is lowering number of Charonia sauliae individuals in natural environment. This species is really rare and e.g. in sea coast of Korea in last years it was noted in the southern part of Korean sea coast and Jeju Island coast only. The Ministry of Environment of Korea designated the trumpet shell as a endangered species. The trumpet shell is protected by law in other countries as well (Australia, Fiji, the Seychelles). Then supporting of the trumpet shell population via artificial propagation appears the only way of this valuable species protection. In order to preparation for its artificial seed production the research on breeding biology ought to carried out and developed. In the past there were few studies about the trumpet shell, and this studies mainly focused on tetradotoxin presence in individuals of this species (the trumpet shell use poison in order to paralyse starfish) and possibility of poisoning among people who ate trumpet shell's flesh with digestive glands. The knowledge about biology of Charonia sauliae is recognized in a lesser degree. But this information is necessary for preparation and improving culture techniques of Charonia sauliae. Then this complex studies focused on various aspects of the trumpet shell biology. Very important question is the influence of main environmental factors e.g. temperature and salinity on different aspects of living processes of Charonia sauliae larvae and spat as well as adult individuals. Particular attention was paid on reproductive aspects of this species biology. The studies on proper diet of this species were important as well. Obtained information will allow to devise methods for artificial seed production of this species. The stage of gonadal development for male trumpet shell was assigned based on the presence or absence of male gametogenic cells within the follicles in the connective tissue. Female developmental stages were assigned based on the presence of ova and oocytes in the gonad. Various characteristics of the follicle, such as the shape and thickness of the follicular wall were used as indicators in order to determine gonadal developmental stages. Ovary and testis development in Charonia sauliae can be divided into five stages: growing, mature, spent, degenerative and resting. The trumpet shell has multiple fecundation and fertilization during the spawning season for out-of-step gonadal development in high-temperature and low-salinity environments. The sex ratio of Charonia sauliae were estimated based on shell length. The overall sex ratio in this study was 1.78:1 (female:male). Individuals with shell lengths from 220~260 mm were mostly females (79.52%), whilst 88,21% of males had shell length in the range 180~220 mm. This results showed that female trumpet shell tended to have larger shells. The effects of different types of food on the growth and reproduction of the trumpet shell Charonia sauliae was investigated in this study. The trumpet shells were reared with three various food types: Asterina pectinifera, Asterias amurensis, and the mixture consisting of this two species. The obtained results showed that growth of the trumpet shell were not significantly influenced by different food types (one-way ANOVA: P>0.05) except the body size of female trumpet shell (P<0.05). The ingestion rates of the trumpet shell were significantly affected by the food types (P<0.05) and the rates of Charonia sauliae fed on A. amurensis were significantly higher that those fed on A. pectinifera (P0.05). However, survival rates of the larvae were significantly influenced by the food types of adult Charonia sauliae(P<0.05). Survival rates of larvae produced by the broodstock fed on A. amurensis were significantly higher than those fed on mixed food and A. pectinifera(P<0.05). Moreover, the larvae incubated under lower water temperature revealed slightly higher survival rate and hatching rate compared with the higher temperature. The aim of presented study was investigation of the effect of water temperature on hatch of egg capsule of Charonia sauliae. Experiments were conducted at different water temperatures (15, 17, 20 and 23°C). The results showed that different water temperatures had significant influence on the trumpet shell eggs capsule stages (P<0.05). Higher water temperature resulted in shorter duration of stages. Water temperature also significantly influenced on the hatching rate of egg capsule of trumpet shell Charonia sauliae (P<0.05), but increase of water temperature did not result in a higher mean hatching rate of egg capsule. The temperature yielding the maximum hatching rate was estimated to be 18.8°C. The number of hatching eggs per egg capsule was depended on water temperature as well (P<0.05). Temperature estimated for maximum number of hatching rate (TMN) was 18.8°C. The obtained results of this study confirmed the effect of water temperature factor on - 134 - eggs development in egg capsules. The reproductive behavior and embryonic development of the gastropod Charonia sauliae inhabiting the south coast of Korea was described under laboratory conditions for the first time. The trumpet shell Charonia sauliae possesses precopulatory mounting behavior during mating period and female individuals usually protect egg mass incubation using their mantle cavity. The embryonic development pattern of Charonia sauliae belongs to typical indirect development; undergoing cleavage stage, blastula stage, gastrulae stage, trochophore, veliger; finally developing to be spat. Comparing with other con-family animals, it could observe the evident trochophore stage and still conserved adequate yolk after hatching out of the egg capsules, which might be facilitate to increase the larval survival opportunity. The effect of water temperature on development, growth and survival rate of larvae and spat of Charonia sauliae were investigated. Experiments were conducted at different water temperatures (10, 15, 20, 25 and 30°C). The results showed that the growth rates of trumpet shell larvae and spat were significant influenced by different temperatures (P<0.05). Duration time of larval stage was negatively correlated with the water temperature (P<0.05). Water temperature significantly influenced on the postlarval size, larval survival and spat survival rates (P<0.05). The temperature estimated for yielding the maximum larval size, larval survival and spat survival rate were 22.6, 19.8 and 19.4°C, respectively. The results indicated that water temperature is a major factor influencing development, growth and survival of trumpet shell larvae and spat, and better development results for trumpet shell could be achieved at 19~23 °C. The effectsof three different microalgae on the development, growth and survival rate of the larvae and spat were investigated. For the larval feeding experiments were used six species: Pavlova lutheri, Tetraselmis suecica, Nannochloris oculata, Isochrysis galbana, Chaetoceros calcitrans and Phaeodactylum tricornutum. For the larval and spat growth and survival experiments were used three species: T. suecica, C. calcitrans and P. tricornutum. Obtained results exhibited that the temporal digestion index (TDI) for the veliger larvae was significantly different for larvae fed the different microalgae species (P<0.05), and better suitable for larval consumption were T. suecica, C. calcitrans and P. tricornutum. The food type had significant influence on the growth and survival of the larvae and spat (P aperture length > initial spiral whorl length. The ratio of shell length to shell width, shell length to aperture length and shell length to initial spiral whorl length was also positively correlated with shell length increasing. The effect of water temperature and salinity on food intake and motility of Charonia sauliae larvae was investigated. Five temperature gradient (5, 10, 15, 20, 25°C) and four salinities gradient (25, 30, 33, 40‰) were tested. The larvae of trumpet shell which had been hatched three days before experiment were used as an experimental subject. Larvae were fed with Isochrysis galbana with the initial concentration 2.5x105 cells ml-1. Changes of food concentration and motility on elapsed time were recorded. On elapsed time the concentrations of Isochrysis galbana decrease gradually in all treatment groups. The most significant decline was noted at the cultural temperature 20°C and salinity 33. That implies that these two environmental factor values were suitable for better feeding activity of larvae. The motility of larvae reared at temperature 5, 10 and 25°C began to decline after 4, 5 and 7 hours respectively. At the water temperature ranged 15 and 20°C the trumpet shell larvae had better acivity. Presented study provided a key information about so far not well known biology of Charonia sauliae which is valuable species. The value of obtained results is high and give the significant contribution in the area of marine biology and aquaculture. This information is essential for artificial propagation of the trumpet shell. Obtained data about reproduction behavior of the trumpet shell will allow to conduct successful reproduction under artificial control conditions. The investigation of larvae dietary requirements as well as adult individuals of Charonia sauliae is very important for receiving high efficiency of survival larvae and spat. Experiments which were carried out also showed optimal diet for adult individuals favourable receiving the best efficiency of reproduction. The trumpet shell's artificial seed production and further artificial propagation of this species will allow use of this species as a useful tool for protection of economically important shellfish culture from harmful organism which are starfish. The strategy of support predators population is widely used technique as a kind of biomanipulation. The results of this study can be use as a preliminary guidelines by industrial and educational institutions for improving artificial culture method of the trumpet shell via further research under this subject. The other very important aspect of artificial breeding of Charonia sauliae is environmental biodiversity protection. This species is now very rare and is strictly protected by law not only in Korea but in other countries as well. Then supporting of Charonia sauliae's population by artificial propagation appears to be reasonable solution.
The trumpet shell Charonia sauliae, belonging to Cymatiidae family (Gastropoda), is very rare and valuable marine mollusk species. This large marine snail (shell length may reach 50 cm) had been used by people for centuries as a kind of food and its shell served to jewellery and trumpet making. Its shells has been sought after by shell collectors which has led to decrease of Charonia sauliae number. Charonia sauliae natural habitats are distributed in tropical and semi-tropical areas of all three oceans, and were noted at the sea shore of the Red Sea, pacific regions of Africa and Madagascar, and the islands of Pacific in the Atlantic Ocean this species individual was catched at sea coast of Southern Europe. This species inhabits bottom zone of the coral reefs at the depth 20~50 m, but it also was found in deeper sea bottom areas, at the depth 200~300 m. The trumpet shell is animal of prey and its food are mainly starfish species Then the trumpet shell plays an important rolein the reef community. Because of fact that starfish are a kind of harmful organisms which threaten many aquatic economically valuable animals, use of Charonia sauliae for control starfish population appears a good solution for supporting mariculture. A real problem now is lowering number of Charonia sauliae individuals in natural environment. This species is really rare and e.g. in sea coast of Korea in last years it was noted in the southern part of Korean sea coast and Jeju Island coast only. The Ministry of Environment of Korea designated the trumpet shell as a endangered species. The trumpet shell is protected by law in other countries as well (Australia, Fiji, the Seychelles). Then supporting of the trumpet shell population via artificial propagation appears the only way of this valuable species protection. In order to preparation for its artificial seed production the research on breeding biology ought to carried out and developed. In the past there were few studies about the trumpet shell, and this studies mainly focused on tetradotoxin presence in individuals of this species (the trumpet shell use poison in order to paralyse starfish) and possibility of poisoning among people who ate trumpet shell's flesh with digestive glands. The knowledge about biology of Charonia sauliae is recognized in a lesser degree. But this information is necessary for preparation and improving culture techniques of Charonia sauliae. Then this complex studies focused on various aspects of the trumpet shell biology. Very important question is the influence of main environmental factors e.g. temperature and salinity on different aspects of living processes of Charonia sauliae larvae and spat as well as adult individuals. Particular attention was paid on reproductive aspects of this species biology. The studies on proper diet of this species were important as well. Obtained information will allow to devise methods for artificial seed production of this species. The stage of gonadal development for male trumpet shell was assigned based on the presence or absence of male gametogenic cells within the follicles in the connective tissue. Female developmental stages were assigned based on the presence of ova and oocytes in the gonad. Various characteristics of the follicle, such as the shape and thickness of the follicular wall were used as indicators in order to determine gonadal developmental stages. Ovary and testis development in Charonia sauliae can be divided into five stages: growing, mature, spent, degenerative and resting. The trumpet shell has multiple fecundation and fertilization during the spawning season for out-of-step gonadal development in high-temperature and low-salinity environments. The sex ratio of Charonia sauliae were estimated based on shell length. The overall sex ratio in this study was 1.78:1 (female:male). Individuals with shell lengths from 220~260 mm were mostly females (79.52%), whilst 88,21% of males had shell length in the range 180~220 mm. This results showed that female trumpet shell tended to have larger shells. The effects of different types of food on the growth and reproduction of the trumpet shell Charonia sauliae was investigated in this study. The trumpet shells were reared with three various food types: Asterina pectinifera, Asterias amurensis, and the mixture consisting of this two species. The obtained results showed that growth of the trumpet shell were not significantly influenced by different food types (one-way ANOVA: P>0.05) except the body size of female trumpet shell (P<0.05). The ingestion rates of the trumpet shell were significantly affected by the food types (P<0.05) and the rates of Charonia sauliae fed on A. amurensis were significantly higher that those fed on A. pectinifera (P0.05). However, survival rates of the larvae were significantly influenced by the food types of adult Charonia sauliae(P<0.05). Survival rates of larvae produced by the broodstock fed on A. amurensis were significantly higher than those fed on mixed food and A. pectinifera(P<0.05). Moreover, the larvae incubated under lower water temperature revealed slightly higher survival rate and hatching rate compared with the higher temperature. The aim of presented study was investigation of the effect of water temperature on hatch of egg capsule of Charonia sauliae. Experiments were conducted at different water temperatures (15, 17, 20 and 23°C). The results showed that different water temperatures had significant influence on the trumpet shell eggs capsule stages (P<0.05). Higher water temperature resulted in shorter duration of stages. Water temperature also significantly influenced on the hatching rate of egg capsule of trumpet shell Charonia sauliae (P<0.05), but increase of water temperature did not result in a higher mean hatching rate of egg capsule. The temperature yielding the maximum hatching rate was estimated to be 18.8°C. The number of hatching eggs per egg capsule was depended on water temperature as well (P<0.05). Temperature estimated for maximum number of hatching rate (TMN) was 18.8°C. The obtained results of this study confirmed the effect of water temperature factor on - 134 - eggs development in egg capsules. The reproductive behavior and embryonic development of the gastropod Charonia sauliae inhabiting the south coast of Korea was described under laboratory conditions for the first time. The trumpet shell Charonia sauliae possesses precopulatory mounting behavior during mating period and female individuals usually protect egg mass incubation using their mantle cavity. The embryonic development pattern of Charonia sauliae belongs to typical indirect development; undergoing cleavage stage, blastula stage, gastrulae stage, trochophore, veliger; finally developing to be spat. Comparing with other con-family animals, it could observe the evident trochophore stage and still conserved adequate yolk after hatching out of the egg capsules, which might be facilitate to increase the larval survival opportunity. The effect of water temperature on development, growth and survival rate of larvae and spat of Charonia sauliae were investigated. Experiments were conducted at different water temperatures (10, 15, 20, 25 and 30°C). The results showed that the growth rates of trumpet shell larvae and spat were significant influenced by different temperatures (P<0.05). Duration time of larval stage was negatively correlated with the water temperature (P<0.05). Water temperature significantly influenced on the postlarval size, larval survival and spat survival rates (P<0.05). The temperature estimated for yielding the maximum larval size, larval survival and spat survival rate were 22.6, 19.8 and 19.4°C, respectively. The results indicated that water temperature is a major factor influencing development, growth and survival of trumpet shell larvae and spat, and better development results for trumpet shell could be achieved at 19~23 °C. The effectsof three different microalgae on the development, growth and survival rate of the larvae and spat were investigated. For the larval feeding experiments were used six species: Pavlova lutheri, Tetraselmis suecica, Nannochloris oculata, Isochrysis galbana, Chaetoceros calcitrans and Phaeodactylum tricornutum. For the larval and spat growth and survival experiments were used three species: T. suecica, C. calcitrans and P. tricornutum. Obtained results exhibited that the temporal digestion index (TDI) for the veliger larvae was significantly different for larvae fed the different microalgae species (P<0.05), and better suitable for larval consumption were T. suecica, C. calcitrans and P. tricornutum. The food type had significant influence on the growth and survival of the larvae and spat (P aperture length > initial spiral whorl length. The ratio of shell length to shell width, shell length to aperture length and shell length to initial spiral whorl length was also positively correlated with shell length increasing. The effect of water temperature and salinity on food intake and motility of Charonia sauliae larvae was investigated. Five temperature gradient (5, 10, 15, 20, 25°C) and four salinities gradient (25, 30, 33, 40‰) were tested. The larvae of trumpet shell which had been hatched three days before experiment were used as an experimental subject. Larvae were fed with Isochrysis galbana with the initial concentration 2.5x105 cells ml-1. Changes of food concentration and motility on elapsed time were recorded. On elapsed time the concentrations of Isochrysis galbana decrease gradually in all treatment groups. The most significant decline was noted at the cultural temperature 20°C and salinity 33. That implies that these two environmental factor values were suitable for better feeding activity of larvae. The motility of larvae reared at temperature 5, 10 and 25°C began to decline after 4, 5 and 7 hours respectively. At the water temperature ranged 15 and 20°C the trumpet shell larvae had better acivity. Presented study provided a key information about so far not well known biology of Charonia sauliae which is valuable species. The value of obtained results is high and give the significant contribution in the area of marine biology and aquaculture. This information is essential for artificial propagation of the trumpet shell. Obtained data about reproduction behavior of the trumpet shell will allow to conduct successful reproduction under artificial control conditions. The investigation of larvae dietary requirements as well as adult individuals of Charonia sauliae is very important for receiving high efficiency of survival larvae and spat. Experiments which were carried out also showed optimal diet for adult individuals favourable receiving the best efficiency of reproduction. The trumpet shell's artificial seed production and further artificial propagation of this species will allow use of this species as a useful tool for protection of economically important shellfish culture from harmful organism which are starfish. The strategy of support predators population is widely used technique as a kind of biomanipulation. The results of this study can be use as a preliminary guidelines by industrial and educational institutions for improving artificial culture method of the trumpet shell via further research under this subject. The other very important aspect of artificial breeding of Charonia sauliae is environmental biodiversity protection. This species is now very rare and is strictly protected by law not only in Korea but in other countries as well. Then supporting of Charonia sauliae's population by artificial propagation appears to be reasonable solution.
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