Larvacean (Chordata, Tunicata) abundance and inferred secondary production off southeastern Brazil

► We studied the temporal variability in larvacean abundance and production. ► Among eleven larvacean species found, Oikopleura longicauda was the most abundant. ► Higher abundance and biomass occurred when the water column was stratified. ► Larvacean had low biomass, but high secondary and detritus production.