This study investigated the embryonic development of Maldives clownfish Amphiprion nigripes under natural conditions (28 - 30℃) at a lagoon of Agatti Island, Lakshadweep, India. The newly deposited fish egg was capsu...This study investigated the embryonic development of Maldives clownfish Amphiprion nigripes under natural conditions (28 - 30℃) at a lagoon of Agatti Island, Lakshadweep, India. The newly deposited fish egg was capsule-shaped and orange-red, with a (0.73 ± 0.04) mm3 yolk containing 5 - 10 fat globules. The embryonic development of fertilized eggs was divided into 26 stages and the time elapsing for each stage was recorded. Results showed that the cleavage was rapid, with the first division observed 1 h 20 min after fertilization. Blastulation occurred 4 h later, followed by gastrulation 12 h after fertilization, with a yolk volume of (0.61 ± 0.06) mm3. The organogenesis process started 22 h after fertilization when the blastopores closed and notochord formation began. The embryonic stage was recorded 24 h later, with the appearance of forebrain, midbrain, hindbrain, melanophores on yolk-sac and 22 somites, and a decreased yolk volume of (0.54 ± 0.08) mm3. Other organs developed well 31 h after fertilization, whereas the heart started beating and blood circulation began 78 h later. Red pigmentation (erytrophores) appeared 96 h after fertilization, with a small yolk volume of (0.22 ± 0.02) mm3. Mouth developed well and eyes were noticeable 120 h later, with head, pectoral fin and tail frequently moving 144 h after fertilization. The embryo reached the pre-hatching stage 168 h later and started to hatch after 170 - 180 h incubation. This study first detailed the embryonic development and yolk absorption of A. nigripes under natural conditions.展开更多
Objective: To test the effects of dietary mannan oligosaccharides (MOS) on clownfish Amphiprion ocellaris (A. ocellaris). Methods: Six levels (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g/kg diet) of MOS were added to the basal ...Objective: To test the effects of dietary mannan oligosaccharides (MOS) on clownfish Amphiprion ocellaris (A. ocellaris). Methods: Six levels (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g/kg diet) of MOS were added to the basal diet (used as control diet) and fed clownfish A. ocellaris [total length (24.21 ± 0.16) mm] for 70 days. Growth performance and tissue protein were measured. Results: The result showed that growth rate was enhanced significantly in fish fed 0.10% and 0.15% MOS in diets compared to fish fed other MOS levels or control (P < 0.05). Survival rate significantly increased in fish fed diets with 0.20% and 0.25% MOS, compared to control. Fraction rates of protein growth were significantly higher in fish fed diets with 0.15%, 0.20%and 0.25% MOS supplementation than those fish fed other MOS inclusion levels and the control (P < 0.04). Dietary MOS concentrations and clownfish growth rates were significantly correlated. Optimal MOS concentration was predicted to be 0.185%, 0.173% and 0.171% at Days 14, 42 and 70, respectively. Conclusions: In conclusion, MOS-supplemented diet benefits for boosting growth, survival and body composition of the clownfish, A. ocellaris.展开更多
Objective:To study the lymphocystis disease virus(LCDV)in two species of marine ormamental fishes through histopathological investigation along with control for differentiating the tissue damage.Methods:Six naturally ...Objective:To study the lymphocystis disease virus(LCDV)in two species of marine ormamental fishes through histopathological investigation along with control for differentiating the tissue damage.Methods:Six naturally infected fishes were collected.They were anaesthetized and subsequently killed by organ dissection.The infected fish organs were aseptically cut off and stored with 10%formalin solution for histological study.Samples were examined for gross pathology including location,distribution,shape,size,colour,consistency and special features of typical external lesions by standard method.Results:The diameter of the tumor nodules ranged from 1 to 2 mm(Amphiprion ocellaris)and 2.5 to 3.5 mm(Amphiprion percula).Light microscopic observation showed over growth of tumor like nodules on the skin or scales and ventral side as well.Numerous hy pertrophied cells with basophilic intracytoplasmic inclusion bodies were in the connective tissues of dermis and between scales on two species.The nucleus of lymphocystis cell were enlarged,irregular and containing basophilic marginated chromatin.Thus,the similarities among cellular patterns of different fish LCDV isolates from different hosts indicated that these profiles do not depend on the host species.Conclusions:In conclusion,this current study of histopathological statement of LCDV may be adequate for a presumptive diagnosis of lymphocystis disease from both marine as well as fresh water fish species.The findings of asymptomatic carriers by histology using infected skin and fin sampling,which does not imply animal killing,could be important tool to epizootics caused by LCDV.This study may be very useful for further molecular studies.展开更多
基金the funding from the Ministry of Environment and Forests (India)
文摘This study investigated the embryonic development of Maldives clownfish Amphiprion nigripes under natural conditions (28 - 30℃) at a lagoon of Agatti Island, Lakshadweep, India. The newly deposited fish egg was capsule-shaped and orange-red, with a (0.73 ± 0.04) mm3 yolk containing 5 - 10 fat globules. The embryonic development of fertilized eggs was divided into 26 stages and the time elapsing for each stage was recorded. Results showed that the cleavage was rapid, with the first division observed 1 h 20 min after fertilization. Blastulation occurred 4 h later, followed by gastrulation 12 h after fertilization, with a yolk volume of (0.61 ± 0.06) mm3. The organogenesis process started 22 h after fertilization when the blastopores closed and notochord formation began. The embryonic stage was recorded 24 h later, with the appearance of forebrain, midbrain, hindbrain, melanophores on yolk-sac and 22 somites, and a decreased yolk volume of (0.54 ± 0.08) mm3. Other organs developed well 31 h after fertilization, whereas the heart started beating and blood circulation began 78 h later. Red pigmentation (erytrophores) appeared 96 h after fertilization, with a small yolk volume of (0.22 ± 0.02) mm3. Mouth developed well and eyes were noticeable 120 h later, with head, pectoral fin and tail frequently moving 144 h after fertilization. The embryo reached the pre-hatching stage 168 h later and started to hatch after 170 - 180 h incubation. This study first detailed the embryonic development and yolk absorption of A. nigripes under natural conditions.
文摘Objective: To test the effects of dietary mannan oligosaccharides (MOS) on clownfish Amphiprion ocellaris (A. ocellaris). Methods: Six levels (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g/kg diet) of MOS were added to the basal diet (used as control diet) and fed clownfish A. ocellaris [total length (24.21 ± 0.16) mm] for 70 days. Growth performance and tissue protein were measured. Results: The result showed that growth rate was enhanced significantly in fish fed 0.10% and 0.15% MOS in diets compared to fish fed other MOS levels or control (P < 0.05). Survival rate significantly increased in fish fed diets with 0.20% and 0.25% MOS, compared to control. Fraction rates of protein growth were significantly higher in fish fed diets with 0.15%, 0.20%and 0.25% MOS supplementation than those fish fed other MOS inclusion levels and the control (P < 0.04). Dietary MOS concentrations and clownfish growth rates were significantly correlated. Optimal MOS concentration was predicted to be 0.185%, 0.173% and 0.171% at Days 14, 42 and 70, respectively. Conclusions: In conclusion, MOS-supplemented diet benefits for boosting growth, survival and body composition of the clownfish, A. ocellaris.
基金Supported by Center for Marine Living Resource and Ecology,Ministry of Earth Sciences(CMLRE-Office Memorandum No:G4/3366/2013).
文摘Objective:To study the lymphocystis disease virus(LCDV)in two species of marine ormamental fishes through histopathological investigation along with control for differentiating the tissue damage.Methods:Six naturally infected fishes were collected.They were anaesthetized and subsequently killed by organ dissection.The infected fish organs were aseptically cut off and stored with 10%formalin solution for histological study.Samples were examined for gross pathology including location,distribution,shape,size,colour,consistency and special features of typical external lesions by standard method.Results:The diameter of the tumor nodules ranged from 1 to 2 mm(Amphiprion ocellaris)and 2.5 to 3.5 mm(Amphiprion percula).Light microscopic observation showed over growth of tumor like nodules on the skin or scales and ventral side as well.Numerous hy pertrophied cells with basophilic intracytoplasmic inclusion bodies were in the connective tissues of dermis and between scales on two species.The nucleus of lymphocystis cell were enlarged,irregular and containing basophilic marginated chromatin.Thus,the similarities among cellular patterns of different fish LCDV isolates from different hosts indicated that these profiles do not depend on the host species.Conclusions:In conclusion,this current study of histopathological statement of LCDV may be adequate for a presumptive diagnosis of lymphocystis disease from both marine as well as fresh water fish species.The findings of asymptomatic carriers by histology using infected skin and fin sampling,which does not imply animal killing,could be important tool to epizootics caused by LCDV.This study may be very useful for further molecular studies.
