Examinando por Autor "Klarian, Sebastian A."
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Ítem A Deep Dive into the Trophic Ecology of Engraulis ringens: Assessing Diet Through Stomach Content and Stable Isotope Analysis(Multidisciplinary Digital Publishing Institute (MDPI), 0024-12) Cárcamo, Carolina; Schultz, Eric T.; Leiva, Francisco; Saavedra, Alvaro; Klarian, Sebastian A.Our study investigates the trophic ecology of the anchoveta (Engraulis ringens). The anchoveta plays a key role in the Greater Humboldt Ecosystem and is extensively exploited by countries from the south-eastern Pacific Ocean. For a comprehensive study of trophic ecology, we employed a combined approach that included stomach content analysis, stable isotope analysis, and scaled mass index of body condition. Our results showed that the multivariate composition of the diet varies significantly between life stage and fishing zones in Chile. Copepods and euphausiids emerged as the dominant prey found in the stomachs across all fisheries zones. Stable isotope analysis revealed significant differences among different zones. The scaled mass index values were higher in the northern zone compared to the southern zones, for both juveniles and adults. This research carries significant implications for fisheries management and conservation efforts, such as the development of targeted management strategies that address variations in the trophic structure of anchoveta across different life stages and fishing zones. © 2024 by the authors.Ítem First record of hyper melanosis in the Patagonian redfish Sebastes oculatus Valenciennes, 1833 (Scorpaenidae) in the southeastern Pacific Ocean(Escuela de Ciencias del Mar, 2023) Sanchez, Jorge; Burgos, Fernando; Melendez, Roberto; Klarian, Sebastian A.The coloration pattern alteration occurs at a low frequency in fish. The excesses of dark pigments in living organisms are known as melanism or melanosis, but a total blackening of the skin is known as hyper melanism or hyper melanosis. Little is known about why the extreme conditions of albinism and melanosis occur among fish. To date, there are no records of melanism for the genus Sebastes. Here, we report the first case of hyper melanosis in rockfish Sebastes oculatus (Patagonian redfish) in the southeastern Pacific Ocean. In 2005, small-scale fishers from Quintay Beach (Valparaiso, Chile) captured a single individual of Patagonian redfish covered with an excess of dark pigmentation. The specimen had a total length of 35.5 cm, and we followed the literature available to determine its morphometric and meristic features. The measurements led us to conclude that the specimen was a black S. oculatus with a rare melanosis condition. Our finding contributes to the knowledge of this species, and we infer that this melanosis case was caused by genetic heritage or some intergenetic hybridization. Still, genetic studies are necessary to confirm this hypothesis. © 2023, Escuela de Ciencias del Mar. All rights reserved.Ítem Food metrics of two meso-benthic chondrichthyans in waters of central Chile(Universidad De Valparaíso, Chile, 2022-10-05) Canales-Cerro, Carlos; Morales, Naití A.; Concha, Francisco J.; Fernandoy, Francisco; Hernández, Sebastian; Meléndez, Roberto; Klarian, Sebastian A.Little has been studied of the food metrics of most chondrichthyans, which provide baseline information for the assessment of fishing status to guide the development of ecosystem-based management plans. Therefore, the main goal of this study was to approach the isotopic niche of Dipturus chilensis and Callorhinchus callorynchus in the Bay of Valparaíso (central Chile). The main findings showed that C. callorynchus presented a narrow ellipse (E= 0.79; RC= 4.14; θ= 1.39), meanwhile D. chilensis, presented an ellipse with greater extension (E= 0.95; RC= 8.23; θ=-0.11), therefore a wide isotopic niche. © The author(s).