ALBERT

Description: Author Posting. © The Author(s), 2019. This is the author's version of the work. It is posted here by permission of Springer Nature for personal use, not for redistribution. The definitive version was published in Zakroff, C., Mooney, T.A. & Wirth, C. Ocean acidification responses in paralarval squid swimming behavior using a novel 3D tracking system. Hydrobiologia, 808(1),(2018):83-106, doi:10.1007/s10750-017-3342-9.

Description: Chronic embryonic exposure to ocean acidification (OA) has been shown to degrade the aragonitic statolith of paralarval squid, Doryteuthis pealeii, a key structure for their swimming behavior. This study examined if day-of-hatching paralarval D. pealeii from eggs reared under chronic OA demonstrated measurable impairments to swimming activity and control. This required the development of a novel, cost-effective, and robust method for 3D motion tracking and analysis. Squid eggs were reared in pCO2 levels in a dose-dependent manner ranging from 400 - 2200 ppm. Initial 2D experiments showed paralarvae in higher acidification environments spent more time at depth. In 3D experiments, velocity, particularly positive and negative vertical velocities, significantly decreased from 400 to 1000 ppm pCO2, but showed non-significant decreases at higher concentrations. Activity and horizontal velocity decreased linearly with increasing pCO2, indicating a subtle impact to paralarval energetics. Patterns may have been obscured by notable individual variability in the paralarvae. Responses were also seen to vary between trials on cohort or potentially annual scales. Overall, paralarval swimming appeared resilient to OA, with effects being slight. The newly developed 3D tracking system provides a powerful and accessible method for future studies to explore similar questions in the larvae of aquatic taxa.

Description: We thank D. Remsen, the MBL Marine Resources Center staff, and MBL Gemma crew for their support in acquiring squid. R. Galat and the facilities staff of the WHOI ESL provided system support. D. McCorkle, KYK Chan, and M. White provided valuable insight on the OA system. E. Moberg, A. Beet, and A. Solow assisted in the development and coding of the 3D model system. We also thank E. Bonk, K. Hoering, M. Lee, D. Weiler, and A. Schlunk for their assistance and input with the experiments. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1122374. This project is funded by NSF Grant No. 1220034.

Description: The literature on identifying larval fish also includes short publications that usually focus on one to several species, as well as detailed keys that present analytical methods for classifying larvae. The number of publications addressing the species identifi cation early life stages of fi sh and referring exclusively to those in the Baltic Sea is relatively small. In most instances, these are publications on the North Sea supplemented with information pertaining to the Baltic Sea. The fi rst wide-ranging work from this fi eld is the book by Ehrenbaum of 1905-1909 which features detailed drawings of fi sh eggs and larvae. Valuable resource is the key by Kazanova 1953 in Russian for the fi sh of the Baltic Sea and its estuaries including useful illustrations especially of herring and sprat larvae. The Atlas larw ryb Bałtyku [Atlas of Larval Baltic Fish] by Mańkowski (1964) in Polish, which is based on the work of Ehrenbaum, is still used widely today. Currently, the basic source of information on juvenile stages of marine fi sh is the key by Russell (1976) that is based on the waters in the vicinity of the British Isles. The following keys are available from the ICES (International Council for the Exploration of the Sea) for certain families of marine fi sh: Clupeidae (Saville, 1964), Ammodytidae (Macer, 1967), Pleuronectidae (Nichols, 1971). The recent publication of a key for North Sea species (Munk and Nielsen, 2005) in which the authors systematize knowledge to date, is valuable resource. The key published by Pinder (2001) dealing with species occurring in the waters of the British Isles is widely used for identifi cation of freshwater fi sh eggs and larvae but especially good are keys by Koblickaya (1981) and Makeeva et.al (2011) in Russian. The publications by Urho (1992, 1996) focus on diff erentiating larvae of brackish water fish. The aim of the book was to supplement the literature dedicated to identifying larval and juvenile fish stages. The book focuses on the species occurring in the southern Baltic Sea and the adjacent Vistula and Szczecin lagoons. The fish described include typically marine species such as cod Gadus morhua, and sprat Sprattus sprattus; freshwater species such as pikeperch Sander lucioperca, and perch Perca fl uviatilis and marine fish that spawn intensively in, among other areas, the brackish waters of the lagoons – such as herring Clupea harengus. Information is included regarding round goby Neogobius melanostomus, the invasive species, which is equally successful inhabiting the coastal waters of the Baltic as the nearly-fresh waters of the lagoons. This book includes 34 fish species belonging to 20 families. While this book does not present a systematic, step-by-step protocol for identifying larvae, it does draw together information that should make this task significantly easier. Most of the published literature includes line drawings, and while this form of presenting morphology does have its merits in that it permits highlighting individual structural characters or pigmentation, it does not always present a full picture of reality. The information presented in this book, which is based on the literature and photographs, should facilitate signifi cantly the work of those interested in studies that require identifying the species of eggs and larvae of fish. The atlas would be a valuable addition to the available literature on early life stages of fish from the waters of the southern Baltic Sea and its lagoons.

Description: Published