Biovolume of Naidinae and Pristininae (Clitellata: Oligochaeta) in neotropical environments

Mass or volume estimators using body surface areas can be useful for environmental quality biomonitoring programs. We propose models of biovolume estimate through biometric information of Aulophorus , Dero , Nais and Pristina . The samples were collected in 51 freshwater systems in the state of São Paulo, between 2004 and 2016. Specific dimensions for each genus of 1,814 total animals were measured and individual biovolume was calculated. The conversion model was performed by linear regression analysis between the biovolume and the specific dimensions, then transformed into a power function, established by allometric law. The biovolume of Aulophorus and Dero can be estimated by the diameter of segment four (D IV ), by the equation Be = 0.775D IV 4.387 (adjusted r 2 = 0.84). For Nais species, the biovolume can be estimated by the diameter of segment seven (D VII ), by the equation Be = 0.913D VII 1.6 (adjusted r 2 = 0.59). For Pristina , the biovolume can be estimate by the diameter of segment eight (D VIII ), by the equation Be = 0.875D VIII 2.11 (adjusted r 2 = 0.69). The application of these models can help us better understand population structure, secondary production and flow of matter and energy in neotropical environments.