Research Product

Effects of the juvenile hormone analogue (S)-methoprene on the larval development and survival of the estuarine mud crab Rhithropanopeus harrisii were examined in the laboratory. Crab larvae continuously exposed to 1000 µg (S )-methoprene/liter did not survive beyond zoeal stage I. With continuous exposure to 100 µg (S)-methoprene/liter, mortality significantly increased through all larval stages except for zoeal stage II, and development duration significantly increased through all zoeal stages and not the premetamorphic megalopa. No supernumerary larval stages occurred with exposure to (S )-methoprene. R. harrisii larvae appear to be more sensitive to the single isomer formulation (S)-methoprene than to the double isomer formulation, (R,S)-methoprene, and these larvae appear to be more sensitive to (S )-methoprene exposure than larvae of the grass shrimp, Palaemonetes pugio.