Cultured <i>versus</i> wild zooplankton and mixoplankton in experimental ecology: what we gain, what we lose and how to bridge the gap

ABSTRACT Laboratory cultures are foundational to marine zooplankton and mixoplankton ecology because they enable controlled, replicated experiments, life-cycle closure and mechanistic inference for theory, modeling, aquaculture and ecotoxicology. Their transferability to nature, however, is filtered by a small number of processes. First, a cultivability bottleneck restricts long-term cultures to a biased subset of handling-tolerant taxa, leaving many oceanic, fragile, or diapause-programmed species underrepresented. This is further complicated by strain-specific divergence and cryptic species. Second, sustained laboratory regimes impose interacting effects of selection and domestication-like adaptation that can shift trait means and reaction norms, particularly for variance- and risk-sensitive traits. Third, chronic laboratory crowding constitutes a distinct selective and plasticity-shaping environment. Fourth, holobiont reassembly in culture alters host–microbiome interactions linked to feeding, detoxification and stress responses. Importantly, phenotypic responses measured in wild populations are also conditional on genetic structure, recent acclimation and carry-over effects; thus, neither cultured nor wild measurements represent neutral baselines. Because grazing and tolerance parameters derived from cultures and short-term field assays dominate uncertainty in ecosystem and biogeochemical models, uncalibrated bias in either direction can propagate into large projection errors. I outline some bridging strategies to map laboratory-derived traits explicitly onto wild trait space.