Influence of temperature on the starvation threshold of nauplii of barnacle Balanus amphitrite (Cirripedia : Thoracica)

An evaluation of starvation threshold of the newly hatched Balanus amphitri te nauplii (instar; II) has been made at three different temperatures (5, 1 5 and 25 degrees C). Earlier studies on starvation in crustacean larvae dem onstrated Point of No Return (PNR) as an index of starvation. PNR is the st ate from which no larvae exposed to stress conditions can recover and compl ete metamorphosis. In this study Ultimate Recovery Point (URP) has been use d as a new index of starvation threshold. URP denotes the number of hours o f starvation after the end of which larvae can recover and continue develop ment. Larvae starved at 5 and 25 degrees C had URP of 204 h and 24 h respec tively. The larvae starved at 5 degrees C for 12 h showed reduced II instar duration (1 d) compared to control II instar duration (1.8 d). At 15 and 2 5 degrees C reduction in instar duration was not evident.