The Deepwater Horizon oil spill in 2010 prompted an enormous survey effort to assess the under-studied, deep-ocean ecosystems of the Gulf of Mexico. The resulting samples and datasets afforded a unique opportunity to study the ecology of a poorly known group of mesopelagic fishes, the barracudinas (Aulopiformes: Paralepididae). Here we address several important data gaps regarding the ecology of the Paralepididae. Our results indicate that a majority of barracudina species are efficient at avoiding research-sized nets, suggesting that their overall abundance has been historically underestimated. Notable differences in vertical distribution, seasonal abundances of sizes classes, and diets were observed among the three major sub-groups of the family, with potential implications to ecosystem-based management of deep-pelagic fisheries. This thesis is dedicated to all the fish, squids, and shrimps that gave their lives to make these data and to those that endured the hardship of the Deepwater Horizon oil spill. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection