Size-mass relationships and the influence of larval and case size on the consumption rates of Triplectides sp. (Trichoptera, Leptoceridae)
Kiffer, Walace Pandolpho; Mendes, Flavio; Rangel, Juliana Vieira; Barbosa, Pâmela; Serpa, Karoline; Moretti, Marcelo da Silva
published: May 1, 2016
ArtNo. ESP141018801005, Price: 29.00 €
Biomass data are frequently used in studies to assess colonization rates, food preferences and secondary production of aquatic invertebrate shredders. Herein, we determined size-mass relationships for larvae of Triplectides sp. using three mathematical models and different body and case variables. Size-mass relationships were determined from 51 individuals who were removed from their cases, measured and had their dry mass determined. Larval body variables provided equations with higher coefficients of determination than that of case variables. Body and tibia lengths were the best predictors in the power and exponential models. Larval body and case variables were also used to investigate Triplectides sp. case selection and the possible influences of larval size and cases on leaf consumption. Relative consumption rates were calculated from 30 individuals who were exposed individu- ally to leaves of a native riparian species (Miconia chartacea). Case dry mass was positively correlated with larval body length. Relative consumption rates varied according with larval size and were negatively correlated with biomass and body length. Our results suggest that tibia length is the most suitable predictor for biomass estimation of larvae of Triplectides sp., and larger larvae consume lower quantities of leaf litter per unit of mass. In addition, case variables should not be used to estimate biomass, which is likely due to the generalist case-selection behavior exhibited by these larvae.