MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps14820

ABSTRACT: Understanding the size-related predatory effects of Mnemiopsis leidyi on ichthyoplankton is crucial for evaluating its effects on fish populations. This study examines the capability of M. leidyi to consume ichthyoplankton and assess whether consumption of fish eggs is dependent on ctenophore size. Laboratory experiments indicated that M. leidyi (4.6 - 10.5 cm total length) ingest fish eggs and larvae (Seriola lalandi). Ingested fish larvae were fully digested, while eggs were often regurgitated undigested; however, most regurgitated eggs were non-viable. Our results also revealed a significant positive relationship between ctenophore size and egg ingestion. These findings suggest that M. leidyi can consume ichthyoplankton. However, the predatory impact that this ctenophore could exert on fish recruitment in areas where these taxa co-occur will most likely depend on ctenophore abundance and body size.