Reproductive success of inbred strain MV31 of the ctenophore Mnemiopsis leidyi in a self-sustaining inland laboratory culture system

Ctenophores are an attractive phylogenetic lineage for studying animal evolution due to their early divergence from other metazoans. Among Ctenophora, <i>Mnemiopsis leidyi</i> is a model system for developmental, cellular, molecular genetic, and evolutionary studies. Until recently, many of these studies were conducted on wild-caught animals, limiting access to researchers on the coast. Here we present significant advancements towards culturing <i>M. leidyi</i> in laboratories without coastal access, enabling its wider use as an experimental and genetic model system. We detail updated feeding regimens that take advantage of co-culturing <i>Brachionus</i> rotifers with <i>Apocyclops</i> copepods, and quantify the reproductive output of our <i>M. leidyi</i> lab strain on this diet. Our updated feeding regimen maintains reproductive fitness comparable to wild-caught individuals. Importantly, we have eliminated the logistical complexities and costs of regularly feeding live larval fish to <i>M. leidyi</i>. Our updated protocols make it feasible to maintain continuous ctenophore cultures independent of access to both coastal populations of wild <i>M. leidyi</i> and larval fish culturing facilities.