Ecology of the barracudinas (Aulopiformes: Paralepididae), a ubiquitous but understudied mesopelagic predatory fish family, in the Gulf of Mexico by Richard Jones A Thesis Submitted to the Faculty of The Charles E. Schmidt College of Science In Partial Fulfillment of the Requirements for the Degree of Master of Science Florida Atlantic University Boca Raton, FL August 2018 Copyright 2018 by Richard Jones ii Acknowledgements I would like to acknowledge everyone who worked with the DEEPEND research consortium to collect these data and their funding body, the Gulf of Mexico Research Initiative, for making that work possible. I would like to give special acknowledgment to Dr. Ray Simpson for the excellent, hand drawn illustrations of each species seen in this work. I’d like to thank Drs. Tracey Sutton, Michael Vecchione, and Tamara Frank for assistance in the identification of gut contents. Thanks to my thesis committee members, Drs. Erik Noonburg and John Baldwin, for their patience and continued support. Special thanks to my adviser, Dr. Jon Moore, for bringing me to this project in every conceivable way and supporting me throughout with quiet patience and understanding. Special thanks to April Cook and Dr. Rosanna Boyle for support with data management and statistical analyses. Notable appreciation to my lab partners, Sebastian Velez, Amanda Hipps, and Carolyn Hanish, for their academic friendship, support, and networking. Thanks to my parents, Johanna and Mike, whose strategic support early on in my graduate education made this work possible. Thanks to my loyal dog, Banjo, for his concern regarding my health during long hours reading and writing at my desk. And very special thanks to my loving wife, Alyssa, for unfathomable understanding and support, burning candles and brewing coffee for me through countless weekends and sleepless nights. iv Abstract Author: Richard Jones Title: Ecology of the barracudinas (Aulopiformes: Paralepididae), a ubiquitous but understudied mesopelagic predatory fish family, in the Gulf of Mexico Institution: Florida Atlantic University Thesis Advisor: Jon A. Moore Degree: Master of Science Year: 2018 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 under- estimated. 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. Ecology of the barracudinas (Aulopiformes: Paralepididae), a ubiquitous but understudied mesopelagic predatory fish family, in the Gulf of Mexico List of Tables ..................................................................................................................... ix List of Figures ..................................................................................................................... x Chapter One: Introduction .................................................................................................. 1 Small swimmers, big problems ....................................................................................... 1 The Deepwater Horizon and the Gulf of Mexico ........................................................... 5 Barracudina: Shots in the Dark ....................................................................................... 8 Objectives ...................................................................................................................... 15 Chapter Two: Methods and Hypotheses ........................................................................... 22 Collection Methods ....................................................................................................... 22 Morphometrics and Descriptions .................................................................................. 27 Statistical Analyses ....................................................................................................... 29 Assessment of Net Evasion ........................................................................................... 31 H10 ............................................................................................................................. 32 Distributional Analyses ................................................................................................. 32 H20 ............................................................................................................................. 33 H30 ............................................................................................................................. 33 H40 ............................................................................................................................. 34 H50 ............................................................................................................................. 34 H60 ............................................................................................................................. 34 vi H70 ............................................................................................................................. 35 H80 ............................................................................................................................. 36 Dietary Analyses ........................................................................................................... 36 H90 ............................................................................................................................. 38 H100 ........................................................................................................................... 39 Ontogenetic Analyses .................................................................................................... 39 H110 ........................................................................................................................... 40 H120 ........................................................................................................................... 40 H130 ........................................................................................................................... 40 Meg Skansi vs. Point Sur............................................................................................... 43 Chapter Three: Results ...................................................................................................... 44 Overview ....................................................................................................................... 44 Species ........................................................................................................................... 51 Anotopterus pharoa.................................................................................................... 51 Lestidiops affinis ....................................................................................................... 52 Lestidiops jayakari ..................................................................................................... 65 Lestidiops mirabilis ................................................................................................... 70 Lestidium atlanticum ................................................................................................. 74 Lestrolepis intermedia ............................................................................................... 81 Macroparalepis affinis ............................................................................................... 93 Magnisudis atlantica .................................................................................................. 94 Paralepis brevirostris ............................................................................................... 105 Paralepis coregonoides ............................................................................................ 112 vii Stemonosudis gracilis .............................................................................................. 119 Stemonosudis intermedia ......................................................................................... 122 Stemonosudis rothschildi ......................................................................................... 127 Stemonosudis siliquiventer ...................................................................................... 134 Sudis atrox ............................................................................................................... 135 Sudis hyalina............................................................................................................ 142 Uncisudis advena ..................................................................................................... 149 Uncisudis quadrimaculata .......................................................................................