Feeding efficiency of the larval ctenophore Mnemiopsis leidyi A. Agassiz (Ctenophora, Lobata)

Abstract

Larval stages of the ctenophore Mnemiopsis leidyi rely on metazoan prey, such as Acartia tonsa nauplii and copepodites, to support high growth rates. However, M. leidyi larvae <0.5 mm (total length) had low retention efficiencies (REs) (proportion of encountered prey actually ingested), 5.78 ± 2.6% (mean ± SE), of nauplii and were often damaged by their encounters. REs of nauplii rapidly increased, 38.94 ± 3.73%, as larvae grew to a size of ∼2.0 mm. For larvae >2.0 mm, nauplii REs plateaued at a mean of 91.03 ± 1.70%. All larvae <0.80 mm were incapable of successfully consuming copepodites. REs of copepodites increased, 23.04 ± 4.68%, as ctenophore larvae developed to ∼2.5 mm. Ctenophore larvae >2.5 mm reached a maximum copepodite RE of 63.75 ± 3.01%.