Length-weight relationship for two fish species from Ipanema National Forest, São Paulo state, Brazil

Abstract

The weight-length relationship is an important tool in the studies of fish biology, physiology and ecology, as this relationship is useful for determining weight and biomass, indicating conditions and allowing comparisons between the growth of different populations, in addition, this relationship can also be used to assess the degree of health of species in the environment. The objective of this study was to present unpublished data on the weight-length relationship (LWRs) of the species Hypostomus ancistroides and Corydoras flaveolus. The fish were sampled in the months of January and June 2013 in rivers of the Ipanema National Forest, sub-basin of the Ipanema River, collected through sieves and trawls. 91 individuals were captured, distributed in one order and two families 52 from Hypostomus ancistroides and 39 from Corydoras flaveolus. The results of this study showed that the Hypostomus ancistroides is outside of what is expected for parameter “a” 0.0058 (0.0043-0.0072), and Corydoras flaveolus is outside of what is expected for parameter “b” 3.75 (3.38-4.11), these date consisted of important biological information for freshwater fish, as this relationship justifies the search for mathematical improvement of the indices, as well as standardization of the types of condition factor used in studies with the same species, facilitating comparisons and, consequently, management and conservation actions.