Size-weight relationships are important for population stock estimates, continuous and large-scale population monitoring, as well as permitting the estimation of population biomass from size-class distribution. While these data are basic and useful for ecological and economical analyses, such estimates for Brazilian jellyfish do not exist. Here we present size-weight relationships for the six most common species of large medusae in the coast of Paraná, southern Brazil: Tamoya haplonema Müller, 1859 and Chiropsalmus quadrumanus (Müller, 1859) - Cubozoa; Olindias sambaquiensis Müller, 1861 - Hydrozoa; Chrysaora lactea Eschscholtz, 1829, Lychnorhiza lucerna Haeckel, 1880 and Phyllorhiza punctata von Lendenfeld, 1884 - Scyphozoa. A regression of the form Y = aXb was used, in which Y = wet weight, X = umbrellar diameter (except for T. haplonema, in which umbrellar height was used), a and b are fitted parameters for each population. The majority of species showed negative allometry, since b was usually less than 3, and varied between 2.415 and 3.028.
Biometry; Cubozoa; Hydrozoa; jellyfish; Scyphozoa
