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Diel vertical migration (DVM) is common in aquatic organisms. The trade‐off between reduced predation risk in deeper, darker waters during the day and increased foraging opportunities closer to the surface at night is a leading hypothesis for DVM behaviour.Diel vertical migration behaviour has dominated research and assessment frameworks for Mysis, an omnivorous mid‐trophic level macroinvertebrate that exhibits strong DVM between benthic and pelagic habitats and plays key roles in many deep lake ecosystems. However, some historical literature and more recent evidence indicate that mysids also remain on the bottom at night, counter to expectations of DVM.We surveyed the freshwater Mysis literature using Web of Science (WoS; 1945–2019) to quantify the frequency of studies on demographics, diets, and feeding experiments that considered, assessed, or included Mysis that did not migrate vertically but remained in benthic habitats. We supplemented our WoS survey with literature searches for relevant papers published prior to 1945, journal articles and theses not listed in WoS, and additional references known to the authors but missing from WoS (e.g. only 47% of the papers used to evaluate in situ diets were identified by WoS).Results from the survey suggest that relatively little attention has been paid to the benthic components of Mysis ecology. Moreover, the literature suggests that reliance on Mysis sampling protocols using pelagic gear at night provides an incomplete picture of Mysis populations and their role in ecosystem structure and function.We summarise current knowledge of Mysis DVM and provide an expanded framework that more fully considers the role of benthic habitat. Acknowledging benthic habitat as an integral part of Mysis ecology will enable research to better understand the role of Mysis in food web processes. [ABSTRACT FROM AUTHOR]

Mysids are known for benthic-pelagic diel vertical migration (DVM), where the population is benthic by day and pelagic by night. However, historical and recent observations in members of the Mysis relicta complex suggests populations exhibit partial DVM, with some remaining benthic at night. We used pelagic net and benthic sled tows to assess diel habitat use by Mysis diluviana at two stations (60 and 100 m deep) in Lake Champlain, USA, during June-November 2015. At both stations, mysids were on the bottom both day and night, but the extent of pelagic habitat use by Mysis varied by site depth. At 60-m, pelagic densities were an order of magnitude lower during the day compared to at night, indicative of benthic-pelagic DVM. Contrary to expectations, we found no diel difference between pelagic and benthic sled density estimates at 100-m, suggesting an equal number of Mysis are benthic day and night, and an equal number are pelagic-day and night at deeper sites. Mean body length of benthic-caught mysids was greater than pelagic-caught individuals, a pattern that was evident both day and night at 100-m. Our findings indicate Mysis partial DVM is common across seasons and influenced by body size and depth. [ABSTRACT FROM AUTHOR]