Feeding greatly enhances swimming endurance of settlement-stage reef-fish larvae of damselfishes (Pomacentridae)

Abstract

Previous studies of the swimming endurance abilities of late-stage larvae of reef fishes have used laboratory swimming chambers and, with one exception, unfed larvae. Based on the exceptional study, we predicted that fed larvae should have much greater endurance than previously reported for unfed larvae. We tested the swimming endurance of the fed late-stage larvae of 6 pomacentrid species and found that all could swim at least twice as long as unfed larvae. The 3 species with larger larvae (12–14 mm standard length: SL) all grew during these experiments in spite of being forced to swim 23.3 h per day. The 3 species with smaller larvae (10–11 mm SL) did not show consistent growth. Unfed laboratory measures of swimming endurance are, therefore, very conservative, and are probably more of an indication of the reserves available to the larvae than a realistic indication of how far the larvae are capable of swimming in the field.