Free amino acids and osmoregulation in penaeid shrimp

Abstract

Shrimp, Penaeus stylirostris Stimpson, were tris and P. aztecus. Regression equations (mmol subjected to increasing and decreasing salinity, 100 g-l) for glycine, glycine plus proline, proline, ranging from 10 to 5 0 %~ Glycine, proline, and alaand total amino acids were 10.156 + 0.1512, 11.426 nine levels increased significantly with increasing + 0.2332, 2.016 + 0.0652, and 21.097 + 0.2492 (desalinity. Only glycine and proline levels decreased creasing salinity), respectively. The regression significantly when the salinity was reduced. Glyequation (mmol 100 g-l) for alanine was 0.685 + cine levels a t 36% were similar in both P. styliros-0.0702 (increasing salinity).Amino acids have been shown to be involved in osmoregulation in crustaceans by several investigators. These studies have been reviewed by Schoffeniels and Gilles (1970). Although total amino acid levels have been shown to participate in osmoregulation in different species of crustaceans, the role of specific amino acids has not been identified. In a recent study Cobb and Vanderzant (1974) indicated that glycine might be the osmoregulator in white shrimp, Penaeus setiferus.In addition to their role as osmoregulators, free amino acids have been implicated as being responsible for much of the flavor in shrimp. Glycine probably causes the sweet taste in freshly caught shrimp (Hashimoto, 1965;Rajendranathan Nair and Bose, 1965). If the levels of certain amino acids increase with increases in salinity, the production of more tasty, cultured shrimp might be possible by manipulating the salinity of the water.In this study the effect of salinity in the range of 10-50%0 on amino acid levels in the tails (abdomen) of Penaeus stylirostris was investigated. Amino acid levels in brown shrimp (Penaeus aztecus) from waters of constant salinity were measured to determine the possible applicability of the results to other species. EXPERIMENTAL SECTIONMaterials. Shrimp, Penaeus stylirostris Stimpson, used in the experiment were reared in ponds of the Texas Agricultural Extension Service's mariculture facilities in Corpus Christi, Tex. Twelve fiberglass tanks (89 X 52 X 55 cm) were equipped with substrate filters, each with two 1.27-cm PVX airlifts. The filters were covered by a 5-cm layer of sand and shell. Circulation and aeration were maintained by a Conde Dry-Air Blower. Each tank was covered by a lid with an internal black polyethylene lining to prevent water evaporation. Salinity was measured with an A.O. Goldberg refractometer. Water pH was measured with an Amstro pH meter.Water a t 46% was pumped directly from the Laguna Madre through 5-fi filters into each tank and maintained a t a depth of 30 cm. Shrimp were seined from the production ponds (-16%) and five shrimp, averaging 110 mm and 10 g, were placed in each tank. The salinity was adjusted to 50%0 with seasalts and the shrimp were allowed to acclimate for 7 days. Tanks containing shrimp were designated by random selection, with two replicates of each of the following: 5 0 L control (shrimp sampled a t e...

Comparison of flavor components in shrimpLitopenaeus vannameicultured in sea water and low salinity water

“…Crustacean muscle contains high concentrations of free amino acids, particularly glycine, proline, arginine, glutamate and alanine 19–22 . In the study, higher concentrations of these amino acids were found in the muscle extracts of samples reared in sea water versus those cultured in low salinity water.…”

“…Crustacean muscle contains high concentrations of free amino acids, particularly glycine, proline, arginine, glutamate and alanine. [19][20][21][22] In the study, higher concentrations of these amino acids were found in the muscle extracts of samples reared in sea water versus those cultured in low salinity water. The effect of environmental salinity on the free amino acid composition and concentration in penaeid shrimp has also been examined.…”

Effects of Probiotics on Survival, Growth and Digestive Enzymes Activities in Freshwater Prawn Macrobrachium rosenbergii (De Man 1879)

“…In addition, the amino acid composition and concentration in the muscle of prawns may affect the quality of the prawn (Wang et al 2004). Crustacean muscles contain high concentration of free amino acids, such as arginine, glycine, proline, glutamine and alanine (Cobb et al 1975). The free amino acids have been shown to function in osmoregulation (Fang et al 1992) and also have a major contribution to the flavor of sea foods (Thompson et al 1980).…”

Effects of salinity on the ions important and sodium‐potassium ATPase in osmoregulation, cortisol, amino acids, digestive and immune enzymes in Scylla paramamosain during indoor overwintering

“…The content of Gly, Arg, Ala and Pro in the muscles of Macrobrachium olfersii under long‐term salinity stress was higher (Mcnamara, Rosa José, Greene, & Augusto, 2004). When the salinity of Penaeus was 10–50‰, Ala, Pro and Gly increased with increased external salinity, and Gly was the main osmotic pressure regulator (Cobb, Conte, & Edwards, 1975). Ala, Pro, Thr, Gly and Arg are the main contributors to osmotic regulation in Penaeus japonicus in low or high salt environments (Via, 1986).…”