Growth, elemental and proximate biochemical composition of larval Amazon River prawn, Macrobrachium amazonicum, reared under different salinity conditions

Abstract

Larvae of the Amazon River prawn, Macrobrachium amazonicum , were reared from hatching through nine stages to the first juvenile instar, comparing four experimental conditions with two salinities (5, 10) and two different types of salt (artificial, natural). Larval biomass growth was measured in terms of changes in dry weight (W), contents of carbon and nitrogen (C, N), and proximate biochemical composition (lipid, protein); moreover, body size (carapace length, CL) was measured in first-stage juveniles. After passing through the non-feeding first larval stage, later stages showed an exponential increase in values of biomass per individual. Rates of increase differed significantly among treatments, showing generally lower growth in experiments with artificial vs. natural salt, and at 5 vs. 10. The same response pattern was found also in CL of early juvenile shrimps. Similar but mostly weaker effects were observed in the percentage C, N, lipid, and protein values (in % of W), and in the C:N mass ratio. Our data indicate that larval rearing of M. amazonicum is feasible with artificial salts and at lower than commonly used standard salinity (10). This makes the cultivation of this species feasible also in aquaculture facilities located at large distance from the coast, where a reduction of costs and logistic investments may compensate for reduced larval growth and production of smaller juveniles. However, these negative effects have to be taken into account in comparisons of growth data from different laboratories. Normal 0 21 false false false DE X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabela normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria,serif; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:DE; mso-fareast-language:EN-US;} Normal 0 21 false false false DE X-NONE X-NONE <w:LsdException Locked=false Priori