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Papers by Francisco Magallon

Research paper thumbnail of Influence of temperature and salinity on the yellowleg shrimp, Penaeus californieinsis Holmes, prophenoloxidase system

The effects of salinity and temperature on plasma protein concentration and total haemocytic prop... more The effects of salinity and temperature on plasma protein concentration and total haemocytic prophenoloxidase (proPO) were determined. Groups of 10 juvenile yellowleg shrimp, Penaeus californiensis Holmes, were acclimated for 20 days at different salinities (28‰, 32‰, 36‰, 40‰ and 44‰ at 25°C) or temperatures (18, 22, 25, 28 and 32°C at 36‰). While total protein levels were not affected, the quantities of proPO increased as salinity was elevated. Temperature affected both haemolymph parameters, showing a significant decrease in proPO at 32°C, and an increase of protein at 28 and 32°C. These results may help to explain the elevated disease susceptibility of shrimp at higher salinities and/or temperatures.

Research paper thumbnail of PP 6 The brown shrimp (Penaeus californiensis) prophenoloxidase system

Research paper thumbnail of Influence of temperature and salinity on the yellowleg shrimp, Penaeus californiensis Holmes, prophenoloxidase system

Aquaculture Research, 1998

The effects of salinity and temperature on plasma protein concentration and total haemocytic prop... more The effects of salinity and temperature on plasma protein concentration and total haemocytic prophenoloxidase (proPO) were determined. Groups of 10 juvenile yellowleg shrimp, Penaeus californiensis Holmes, were acclimated for 20 days at different salinities (28‰, 32‰, 36‰, 40‰ and 44‰ at 25°C) or temperatures (18, 22, 25, 28 and 32°C at 36‰). While total protein levels were not affected, the quantities of proPO increased as salinity was elevated. Temperature affected both haemolymph parameters, showing a significant decrease in proPO at 32°C, and an increase of protein at 28 and 32°C. These results may help to explain the elevated disease susceptibility of shrimp at higher salinities and/or temperatures.

Research paper thumbnail of Growth potential of wild juvenile Penaeus stylirostris in earthen ponds receiving chemical and organic fertilizers, and pelleted feed

Aquacultural Engineering, 1995

Research paper thumbnail of Improved digestion and initial performance of whiteleg shrimp using organic salt supplements

Organic acids or their salts are promising feed additives for aquatic animals to improve growth p... more Organic acids or their salts are promising feed additives for aquatic animals to improve growth performance. We determined the effect of supplementing diets with sodium salts (formate, acetate, lactate, propionate, butyrate, fumarate, succinate and citrate) on trypsin and chymotrypsin activities, in vitro digestibility and zootechnical performance in the whiteleg shrimp (Litopenaeus vannamei). Shrimp trypsin and chymotrypsin activity increased in the presence of acetate and propionate and decreased in the presence of lactate and citrate. The highest in vitro protein digestibility of the experimental diets, using shrimp enzymes, was obtained for diets containing fumarate and succinate, which was significantly greater than the control diet (no supplements). In a growth trial, the highest final weights were in shrimp fed diets supplemented with fumarate, succinate, butyrate and propionate, increasing 53%, 46%, 38% and 29%, respectively, compared to the control. Shrimp that were fed diets with fumarate digested more feed and had a feed conversion ratio 23% higher than the control shrimp. Shrimp survival did not differ among treatments. We concluded that organic salts in the diet modify digestive enzymatic activity and in vitro protein digestibility of whiteleg shrimp. Fumarate, succinate, butyrate and propionate have potential as feed additives for L. vannamei.

Research paper thumbnail of Influence of temperature and salinity on the yellowleg shrimp, Penaeus californieinsis Holmes, prophenoloxidase system

The effects of salinity and temperature on plasma protein concentration and total haemocytic prop... more The effects of salinity and temperature on plasma protein concentration and total haemocytic prophenoloxidase (proPO) were determined. Groups of 10 juvenile yellowleg shrimp, Penaeus californiensis Holmes, were acclimated for 20 days at different salinities (28‰, 32‰, 36‰, 40‰ and 44‰ at 25°C) or temperatures (18, 22, 25, 28 and 32°C at 36‰). While total protein levels were not affected, the quantities of proPO increased as salinity was elevated. Temperature affected both haemolymph parameters, showing a significant decrease in proPO at 32°C, and an increase of protein at 28 and 32°C. These results may help to explain the elevated disease susceptibility of shrimp at higher salinities and/or temperatures.

Research paper thumbnail of PP 6 The brown shrimp (Penaeus californiensis) prophenoloxidase system

Research paper thumbnail of Influence of temperature and salinity on the yellowleg shrimp, Penaeus californiensis Holmes, prophenoloxidase system

Aquaculture Research, 1998

The effects of salinity and temperature on plasma protein concentration and total haemocytic prop... more The effects of salinity and temperature on plasma protein concentration and total haemocytic prophenoloxidase (proPO) were determined. Groups of 10 juvenile yellowleg shrimp, Penaeus californiensis Holmes, were acclimated for 20 days at different salinities (28‰, 32‰, 36‰, 40‰ and 44‰ at 25°C) or temperatures (18, 22, 25, 28 and 32°C at 36‰). While total protein levels were not affected, the quantities of proPO increased as salinity was elevated. Temperature affected both haemolymph parameters, showing a significant decrease in proPO at 32°C, and an increase of protein at 28 and 32°C. These results may help to explain the elevated disease susceptibility of shrimp at higher salinities and/or temperatures.

Research paper thumbnail of Growth potential of wild juvenile Penaeus stylirostris in earthen ponds receiving chemical and organic fertilizers, and pelleted feed

Aquacultural Engineering, 1995

Research paper thumbnail of Improved digestion and initial performance of whiteleg shrimp using organic salt supplements

Organic acids or their salts are promising feed additives for aquatic animals to improve growth p... more Organic acids or their salts are promising feed additives for aquatic animals to improve growth performance. We determined the effect of supplementing diets with sodium salts (formate, acetate, lactate, propionate, butyrate, fumarate, succinate and citrate) on trypsin and chymotrypsin activities, in vitro digestibility and zootechnical performance in the whiteleg shrimp (Litopenaeus vannamei). Shrimp trypsin and chymotrypsin activity increased in the presence of acetate and propionate and decreased in the presence of lactate and citrate. The highest in vitro protein digestibility of the experimental diets, using shrimp enzymes, was obtained for diets containing fumarate and succinate, which was significantly greater than the control diet (no supplements). In a growth trial, the highest final weights were in shrimp fed diets supplemented with fumarate, succinate, butyrate and propionate, increasing 53%, 46%, 38% and 29%, respectively, compared to the control. Shrimp that were fed diets with fumarate digested more feed and had a feed conversion ratio 23% higher than the control shrimp. Shrimp survival did not differ among treatments. We concluded that organic salts in the diet modify digestive enzymatic activity and in vitro protein digestibility of whiteleg shrimp. Fumarate, succinate, butyrate and propionate have potential as feed additives for L. vannamei.