Is Chelidonichthys lucerna (Linnaeus, 1758) a Marine Estuarine-Dependent Fish? Insights from Saccular Otolith Microchemistry

Abstract

Tub gurnard, Chelidonichthys lucerna (Linnaeus, 1758), is a Mediterranean-Atlantic benthic species usually captured as by-catch by Portuguese traditional fisheries and considered the most important commercial fish species of the family Triglidae. However, to date, little is known about its habitat residency and whether the species can be considered a marine estuarine-dependent fish. Otolith microchemistry has proven effective in providing information about fish movement patterns throughout different water salinities. In this study, core-to-edge transects of Sr:Ca in the fish saccular otoliths of 35 juveniles of C. lucerna captured in March 2007 by a scientific survey along the Portuguese coast were used to assess the species movement between brackish and marine waters. Data suggest that most individuals (97%) have an estuarine-dependent profile, with 63% showing a clear presence in marine waters during the early life history periods. Evidence of an estuarine residence throughout the fish life cycle was found in only 3% of individuals. Ba:Ca profiles did not reflect an inverse relationship with Sr:Ca salinity results but corroborated findings from other authors about the influence of upwelling processes and freshwater runoffs on Ba incorporation into the otoliths of coastal fish. Furthermore, the data also showed that C. lucerna can occupy and migrate among habitats with diverse salinity degrees, showing high environmental plasticity and adaptation.

Travelling in Microphis (Teleostei: Syngnathidae) Otoliths with Two-Dimensional X-ray Fluorescence Maps: Twists and Turns on the Road to Strontium Incorporation

“…Nowadays, the most commonly used method is 1D transect or point-by-point methods such as laser ablation coupled to an inductively coupled plasma mass spectrometer (LA-ICPMS). This method has many uses such as in the study of the amphidromous life cycle of Sicydiinae gobies [ 5 ], stock assessment of the migratory porcupine fish by Sr marking [ 21 ] or the study of the migratory behaviour of commercial fish [ 22 ]. With this method, researchers can focus on the early growth region [ 23 ] or can obtain life history profiles along a transect over a chosen growth axis of the otolith; these types of transects are often used to detect environmental changes during the individual’s life such as migrations between water masses of varying salinity [ 5 , 12 , 24 ].…”

Chelidonichthys lucerna (Linnaeus, 1758) Population Structure in the Northeast Atlantic Inferred from Landmark-Based Body Morphometry

“…Following a larval pelagic phase [27,28], C. lucerna exhibits a particular pattern of seasonal migratory movements during the juvenile and adult stages within its depth ranges throughout the year, showing a more pronounced concentration of individuals in shallower depths during spring and summer, moving progressively into deeper waters in the winter period [29][30][31]. Recently, it has been shown that C. lucerne, although mainly a marine fish, can occupy and migrate among habitats with diverse salinity degrees, thereby showing high environmental plasticity and adaptation [32]. In 2006, ICES classified C. lucerna as a potential species for commercial exploitation and has recommended that monitoring programs should be conducted to acquire information on biological parameters for stock assessment purposes [33].…”