Physiological and genetic variations in domesticated and wild populations of Litopenaeus vannamei fed with different carbohydrate levels
Por:
Arena L., Cuzon G., Pascual C., Gaxiola G., Soyez C., Van Wormhoudt A., Rosas C.
Publicada:
1 ene 2003
Resumen:
The relationship between polymorphism of ?-amylase and physiologic and biochemical behavior of L. vannamei was used to determine whether artificial selection based on body weight and body size affect the adaptation ability of shrimp to use dietary carbohydrates as a source of energy. Shrimp fitness was addressed by measurement of energy balance using growth (P), oxygen consumption (R), and ammonia excretion (U) of juveniles from wild, 7th, and 25th generations of cultured shrimp. Hemolymph glucose, digestive gland glycogen, amylase activity, and amylase polymorphism was also evaluated in the three shrimp populations. Heterozygosity, amylase activity, and starch metabolism were affected by artificial selection of L. vannamei. Shrimp from a 25th-cultured generation had less heterozygosity and physiologic alteration than did wild shrimp. Shrimp from a 7th-generation cultured shrimp population showed an intermediate state of genetic and physiologic alteration. Although a statistical comparisons cannot be made between the three studied populations, it is evident that there is a reduction in amylase activity related to shrimp domestication, with high values in wild shrimp (between 24 to 39 IU mg-1 protein), intermediate in 7th-generation cultured shrimp (between 16 to 25 IU mg-1 protein), and low in 25th-generation cultured shrimp (between 3.6 to 15.8 IU mg-1 protein). A reduction in the frequency of alleles of amylase genes possibly related to domestication of shrimp was also demonstrated. It appears that the reduction of allele frequency of amylase genes affected the adaptative ability of shrimp to use dietary carbohydrates as a source of energy and molecules and caused farmed populations to be protein dependent. Results of energy balance studies indicate that there are differences in production efficiency (P/AS) between populations: a reduction in P/AS as a function of generations of farmed shrimp suggests that efficiency with which shrimp transform energy into biomass is reduced with artificial selection.
Filiaciones:
Arena L.:
Lab. de Biol. Marina Experimental, Apdo. Post 69, Cd. del Carmen, Camp., Mexico
Cuzon G.:
Ctr. Océanol. du Pacifique, BP 7004, Taravao, French Polynesia
Pascual C.:
Lab. de Biol. Marina Experimental, Apdo. Post 69, Cd. del Carmen, Camp., Mexico
Gaxiola G.:
Lab. de Biol. Marina Experimental, Apdo. Post 69, Cd. del Carmen, Camp., Mexico
Soyez C.:
Ctr. Océanol. du Pacifique, BP 7004, Taravao, French Polynesia
Van Wormhoudt A.:
Station du Biologie, Mar. du Mus. Natl. d'Hist. Naturelle, Collége de France, BP 225, 29900, Concarneau, France
Rosas C.:
Lab. de Biol. Marina Experimental, Apdo. Post 69, Cd. del Carmen, Camp., Mexico
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