Respiration rate and swimming activity of larvae of two sub-tidal nassariid gastropods under reduced oxygen levels: Implications for their distributions in Hong Kong waters

► 48 h LC50 values of N. siquijorensis larvae was lower than that of N. conoidalis. ► A greater reduction in respiration rate under hypoxia was observed for N. siquijorensis. ► Swimming velocity was reduced at a lower oxygen level for N. siquijorensis. ► These may help explain the dominance of N. siquijorensis in the eutrophic Tolo Harbour, Hong Kong.