During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sp...During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sperm on landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs during spawning. There was no significant difference in egg survival to the eyed-stage of development or to hatch among any of the treatments, with a mean (SE) percent survival to the eyed stage of 63.9 (5.8). These results indicate that only relatively short residence times of activated milt on eggs during landlocked fall Chinook salmon spawning are needed to ensure egg survival, resulting in potentially substantial reductions in production-level spawning times and associated labor costs.展开更多
Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outd...Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were used.Triplicate groups of male C.gariepinus[(303.22±1.89)g body weight]were fed with four diets supplemented T.conophorum seed powder respectively,a control diet without T.conophorum seed powder 2 times a day at 3%of body weight for 70 days.Male C.gariepinus broodstocks[average individual weight,(303.22±1.89)g]were randomly distributed with density of 10 fish into 15 outdoor concrete tanks.At the end of the 70-day experiment,gonado-somatic index and reproductive indices were determined.Results:Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment.Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg/kg T.conophorum seed powder compared to other experimental diets.The results indicated that supplement diets with medicinal plant(T.conophorum)enhanced growth and improved gonado-somatic index,and reproductive indices of male C.gariepinus broodstocks.Conclusions:T.conophorum have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.展开更多
This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Niger...This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Nigeria,while the fish’s milt was collected and analyzed for microbial load at laboratory of the Department of Microbiology,Federal University of Agriculture,Abeokuta,Ogun State.The molecular characterization of the amplicon was done at International Institute of Tropical Agriculture,Ibadan.Bio-edit was used for importing and mining nucleotide sequences into gene bank.As revealed by the results,bacterial organisms that were present in the milt of Clarias gariepinus are Aeromonas caviae,Proteus mirabilis,Serratia rubidaea,Pseudomonas mosselii,Acinetobacter soli and Klebsiella variicola.The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86%-97.04%and their accession numbers.These bacteria indicated high levels of faecal contamination in the environment.In conclusion,bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.Therefore,fish farmers should maintain a hygiene and serene environment during breeding and culturing of catfish.展开更多
文摘During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sperm on landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs during spawning. There was no significant difference in egg survival to the eyed-stage of development or to hatch among any of the treatments, with a mean (SE) percent survival to the eyed stage of 63.9 (5.8). These results indicate that only relatively short residence times of activated milt on eggs during landlocked fall Chinook salmon spawning are needed to ensure egg survival, resulting in potentially substantial reductions in production-level spawning times and associated labor costs.
文摘Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were used.Triplicate groups of male C.gariepinus[(303.22±1.89)g body weight]were fed with four diets supplemented T.conophorum seed powder respectively,a control diet without T.conophorum seed powder 2 times a day at 3%of body weight for 70 days.Male C.gariepinus broodstocks[average individual weight,(303.22±1.89)g]were randomly distributed with density of 10 fish into 15 outdoor concrete tanks.At the end of the 70-day experiment,gonado-somatic index and reproductive indices were determined.Results:Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment.Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg/kg T.conophorum seed powder compared to other experimental diets.The results indicated that supplement diets with medicinal plant(T.conophorum)enhanced growth and improved gonado-somatic index,and reproductive indices of male C.gariepinus broodstocks.Conclusions:T.conophorum have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.
文摘This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Nigeria,while the fish’s milt was collected and analyzed for microbial load at laboratory of the Department of Microbiology,Federal University of Agriculture,Abeokuta,Ogun State.The molecular characterization of the amplicon was done at International Institute of Tropical Agriculture,Ibadan.Bio-edit was used for importing and mining nucleotide sequences into gene bank.As revealed by the results,bacterial organisms that were present in the milt of Clarias gariepinus are Aeromonas caviae,Proteus mirabilis,Serratia rubidaea,Pseudomonas mosselii,Acinetobacter soli and Klebsiella variicola.The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86%-97.04%and their accession numbers.These bacteria indicated high levels of faecal contamination in the environment.In conclusion,bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.Therefore,fish farmers should maintain a hygiene and serene environment during breeding and culturing of catfish.
