aquaCalc 1.0: Software to Aid Design and Operation of Aquaculture Systems. User'sManual for Macinstosh and Windows Versions

摘要

Several length and weight measurements commonly are used to characterize the sizeof cultured organisms. For example, over the course of a production run, samples of heads-on shrimp may be weighted to estimate biomass, as feeding regimes are calibrated in this way. These shrimp, however, likely will be marketed either in terms of the number of tails per pound or the number of whole animals per kilogram--not in terms of their individual, heads-on mass. Further, it often is quicker and requires less handling to measure the length of an individual--be it carapace length of a shrimp or standard length of a fish--rather than to measure its weight. Growth data reported in the literature frequently are expressed in terms of a length, such as the distance in millimeters from the edge of the carapace to the posterior end of the eye socket of a shrimp. However, such measurements are inconvenient for the commercial aquaculturist interested in comparing these data with his own, since the latter most often expressed in terms of whole weight. In such cases, the need naturally arises to convert between length and weight. Conversion equations, derived empirically from length and weight data of a large, well-defined sample, serve this purpose. Those employed in the L/W Conversions dialog were taken from references cited at the end of this section, and several of these relationships are tabulated below for species supported in this version of aquaCalc.