Effects of the duration and timing of starvation during larval life on themetamorphosis and initial juvenile size of the polychaete Hydroides elegans (Haswell)

The larvae of the polychaete Hydroides elegans were exposed to different fe eding schedules to evaluate the effects of starvation on metamorphosis and initial juvenile volume. The timing of starvation (early or late in develop ment) and the total number of days of feeding (3, 5 or 8 days) at 24 degree sC had significant effects on the percentage of larvae that successfully co mpleted metamorphosis and on the volume of the post-metamorphic juveniles. However, the duration of starvation (2, 4, 6 or 8 days) did not influence m etamorphosis or juvenile volume. For larvae that had fed for 3 or 5 days, t hose that were starved at the beginning of development had a higher percent age of successful metamorphosis and produced larger juveniles compared with those starved after an initial 3-day feeding period, Larvae that had been allowed to feed for a total of 8 days were not affected by the timing of st arvation. The percentage metamorphosis was lower in larvae that had fed for 3 days (16%), but was not significantly different between those that fed f or 5 days (47%) compared to 8 days (47%). However, juvenile volume increase d with the number of days of feeding from 0.95 nl after 3 days to 1.35 nl a fter 5 days, to 1.91 nl after 8 days of feeding. Discontinuous feeding redu ced the proportion of larvae undergoing metamorphosis and juvenile volume c ompared to larvae continuously fed for only 5 days, but had no effect on la rvae that fed for 8 days. The larvae of this extremely successful fouling s pecies are remarkably tolerant of starvation and seem to require approximat ely 5 days of continuous feeding to achieve high levels of metamorphic succ ess and large initial juvenile volume. (C) 2001 Elsevier Science B.V. All r ights reserved.