EFFECT OF TEMPERATURE AND SALINITY ON RESPIRATORY RATE AND DEVELOPMENT OF EARLY LARVAL STAGES OF MACROBRACHIUM-ACANTHURUS (WIEGMANN, 1836) (DECAPODA, PALAEMONIDAE)

Macrobrachium acanthurus larvae were reared at different salinity and temperature combinations (0, 7, 14, 21, 28 and 35 parts per thousand S at 15, 20, 25 and 30 degrees C). The survival and respiratory rate we re measured for zoea I, II, III and IV. The oxygen consumption rates w ere measured at 25 degrees C in all tested salinities, using a Warburg respirometer. Larvae reared in fresh water died at stage I in all tes ted temperatures. The highest survival rates were obtained at 25 and 3 0 degrees C within a range of 14-21 parts per thousand S. The metaboli c rate-salinity (M-S) curves for all zoeae studied showed lower values either in 14 (zoeae II and III) or 21 parts per thousand S (zoeae I a nd IV). However, values were not significantly different for zoeae III and IV, which showed to be more salinity independent. (C) 1997 Elsevi er Science Inc.