Abstract

AZEVEDO, Fábio de; DIAS, Juliana Déo; BRAGHIN, Louizi de Souza Magalhães  and  BONECKER, Cláudia Costa. Length-weight regressions of the microcrustacean species from a tropical floodplain. Acta Limnol. Bras. [online]. 2012, vol.24, n.1, pp. 01-11.  Epub Aug 16, 2012. ISSN 2179-975X.  http://dx.doi.org/10.1590/S2179-975X2012005000021.

AIM: This study presents length-weight regressions adjusted for the most representative microcrustacean species and young stages of copepods from tropical lakes, together with a comparison of these results with estimates from the literature for tropical and temperate regions; METHODS: Samples were taken from six isolated lakes, in summer and winter, using a motorized pump and plankton net. The dry weight of each size class (for cladocerans) or developmental stage (for copepods) was measured using an electronic microbalance; RESULTS: Adjusted regressions were significant. We observed a trend of under-estimating the weights of smaller species and overestimating those of larger species, when using regressions obtained from temperate regions; CONCLUSION: We must be cautious about using pooled regressions from the literature, preferring models of similar species, or weighing the organisms and building new models.

Keywords : dry weight; cladocerans; copepods; biomass; secondary productivity.